| Message ID | 1430713734-12175-1-git-send-email-dinguyen@opensource.altera.com (mailing list archive) |
|---|---|
| State | Rejected |
| Headers | show |
Hi Krzystof, On 5/4/15 12:30 AM, Krzysztof Kozlowski wrote: > 2015-05-04 13:28 GMT+09:00 <dinguyen@opensource.altera.com>: >> From: Dinh Nguyen <dinguyen@opensource.altera.com> >> >> Turn on the clock to the PL330 DMA if there is a clock node provided. > > Why? There is no explanation in the patch for this important question - why? > > Amba bus already does this and provide a wrapper function. > Additionally that would mess up with runtime PM and clock > enable/disable. I don't see the clock for the DMA getting turned on at all, which is why after the kernel has booted, the filesystem tries to open up a serial port using DMA and the system hangs. The failure is seen here: http://arm-soc.lixom.net/bootlogs/next/next-20150504/socfpga-arm-multi_v7_defconfig.html This only happens with the multi_v7_defconfig, because the PL330 DMA is getting built into the kernel, while the socfpga_defconfig does not enable the PL330. The DTS for the socfpga platform looks like this: pdma: pdma@ffe01000 { compatible = "arm,pl330", "arm,primecell"; reg = <0xffe01000 0x1000>; interrupts = <0 104 4>, <0 105 4>, ... #dma-cells = <1>; #dma-channels = <8>; #dma-requests = <32>; clocks = <&l4_main_clk>; clock-names = "apb_pclk"; }; Perhaps I have the wrong designation for clock-names and the amba bus is not able to pick up the correct clock? Dinh -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
2015-05-04 22:28 GMT+09:00 Dinh Nguyen <dinguyen@opensource.altera.com>: > Hi Krzystof, > > On 5/4/15 12:30 AM, Krzysztof Kozlowski wrote: >> 2015-05-04 13:28 GMT+09:00 <dinguyen@opensource.altera.com>: >>> From: Dinh Nguyen <dinguyen@opensource.altera.com> >>> >>> Turn on the clock to the PL330 DMA if there is a clock node provided. >> >> Why? There is no explanation in the patch for this important question - why? >> >> Amba bus already does this and provide a wrapper function. >> Additionally that would mess up with runtime PM and clock >> enable/disable. > > I don't see the clock for the DMA getting turned on at all, which is why > after the kernel has booted, the filesystem tries to open up a serial > port using DMA and the system hangs. The failure is seen here: > > http://arm-soc.lixom.net/bootlogs/next/next-20150504/socfpga-arm-multi_v7_defconfig.html Thanks! The amba bus and pl330 should enable the clock and then disable it after probing: static int amba_probe(struct device *dev) { ... ret = amba_get_enable_pclk(pcdev); ... I wonder why do you think it is not enabled at all? > > This only happens with the multi_v7_defconfig, because the PL330 DMA is > getting built into the kernel, while the socfpga_defconfig does not > enable the PL330. It makes sense. If pl330 driver is not enabled then necessary clocks are turned on by bootloader. Probing pl330 effectively disables the clock (if DMA is not used). > The DTS for the socfpga platform looks like this: > > pdma: pdma@ffe01000 { > compatible = "arm,pl330", "arm,primecell"; > reg = <0xffe01000 0x1000>; > interrupts = <0 104 4>, > <0 105 4>, > ... > #dma-cells = <1>; > #dma-channels = <8>; > #dma-requests = <32>; > clocks = <&l4_main_clk>; > clock-names = "apb_pclk"; > }; > > Perhaps I have the wrong designation for clock-names and the amba bus is > not able to pick up the correct clock? I have two ideas: 1. Is this really the clock for the DMA? If DMA is not used then disabling it should be OK. 2. Disabling the clock may effectively disable its parent or grandparent if there are not more users. Maybe some other driver needs these parents to be enabled? This was the issue for at least one similar error (on Exynos boards). Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
+CC Olof On 5/4/15 8:50 AM, Krzysztof Kozlowski wrote: > 2015-05-04 22:28 GMT+09:00 Dinh Nguyen <dinguyen@opensource.altera.com>: >> Hi Krzystof, >> >> On 5/4/15 12:30 AM, Krzysztof Kozlowski wrote: >>> 2015-05-04 13:28 GMT+09:00 <dinguyen@opensource.altera.com>: >>>> From: Dinh Nguyen <dinguyen@opensource.altera.com> >>>> >>>> Turn on the clock to the PL330 DMA if there is a clock node provided. >>> >>> Why? There is no explanation in the patch for this important question - why? >>> >>> Amba bus already does this and provide a wrapper function. >>> Additionally that would mess up with runtime PM and clock >>> enable/disable. >> >> I don't see the clock for the DMA getting turned on at all, which is why >> after the kernel has booted, the filesystem tries to open up a serial >> port using DMA and the system hangs. The failure is seen here: >> >> http://arm-soc.lixom.net/bootlogs/next/next-20150504/socfpga-arm-multi_v7_defconfig.html > > Thanks! > > The amba bus and pl330 should enable the clock and then disable it > after probing: > static int amba_probe(struct device *dev) > { > ... > ret = amba_get_enable_pclk(pcdev); > ... > > I wonder why do you think it is not enabled at all? I've checked it down to the register level that the gate for this clock does not get set. > >> >> This only happens with the multi_v7_defconfig, because the PL330 DMA is >> getting built into the kernel, while the socfpga_defconfig does not >> enable the PL330. > > It makes sense. If pl330 driver is not enabled then necessary clocks > are turned on by bootloader. Probing pl330 effectively disables the > clock (if DMA is not used). > >> The DTS for the socfpga platform looks like this: >> >> pdma: pdma@ffe01000 { >> compatible = "arm,pl330", "arm,primecell"; >> reg = <0xffe01000 0x1000>; >> interrupts = <0 104 4>, >> <0 105 4>, >> ... >> #dma-cells = <1>; >> #dma-channels = <8>; >> #dma-requests = <32>; >> clocks = <&l4_main_clk>; >> clock-names = "apb_pclk"; >> }; >> >> Perhaps I have the wrong designation for clock-names and the amba bus is >> not able to pick up the correct clock? > > I have two ideas: > 1. Is this really the clock for the DMA? If DMA is not used then > disabling it should be OK. Yes, this is the clock for the DMA. Yeah, leaving this clock off is fine, until the DMA gets used. Up until v4.0, SoCFPGA was not using the DMA at all, but in v4.0, there was a patch to assign the UARTs to it's DMA channel. https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/arch/arm/boot/dts/socfpga.dtsi?id=78c03c7af89721bd8a4428408a8cc7b53972e4b8 > 2. Disabling the clock may effectively disable its parent or > grandparent if there are not more users. Maybe some other driver needs > these parents to be enabled? This was the issue for at least one > similar error (on Exynos boards). > I'll check up on these issues. When I was debugging this issue, the l4_main_clk is only used by the DMA, so it was not getting turned on by an other drivers. Thanks, Dinh -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 05/04/2015 09:06 AM, Dinh Nguyen wrote: > +CC Olof > > On 5/4/15 8:50 AM, Krzysztof Kozlowski wrote: >> 2015-05-04 22:28 GMT+09:00 Dinh Nguyen <dinguyen@opensource.altera.com>: >>> Hi Krzystof, >>> >>> On 5/4/15 12:30 AM, Krzysztof Kozlowski wrote: >>>> 2015-05-04 13:28 GMT+09:00 <dinguyen@opensource.altera.com>: >>>>> From: Dinh Nguyen <dinguyen@opensource.altera.com> >>>>> >>>>> Turn on the clock to the PL330 DMA if there is a clock node provided. >>>> >>>> Why? There is no explanation in the patch for this important question - why? >>>> >>>> Amba bus already does this and provide a wrapper function. >>>> Additionally that would mess up with runtime PM and clock >>>> enable/disable. >>> >>> I don't see the clock for the DMA getting turned on at all, which is why >>> after the kernel has booted, the filesystem tries to open up a serial >>> port using DMA and the system hangs. The failure is seen here: >>> >>> http://arm-soc.lixom.net/bootlogs/next/next-20150504/socfpga-arm-multi_v7_defconfig.html >> >> Thanks! >> >> The amba bus and pl330 should enable the clock and then disable it >> after probing: >> static int amba_probe(struct device *dev) >> { >> ... >> ret = amba_get_enable_pclk(pcdev); >> ... >> >> I wonder why do you think it is not enabled at all? > > I've checked it down to the register level that the gate for this clock > does not get set. > >> >>> >>> This only happens with the multi_v7_defconfig, because the PL330 DMA is >>> getting built into the kernel, while the socfpga_defconfig does not >>> enable the PL330. >> >> It makes sense. If pl330 driver is not enabled then necessary clocks >> are turned on by bootloader. Probing pl330 effectively disables the >> clock (if DMA is not used). >> >>> The DTS for the socfpga platform looks like this: >>> >>> pdma: pdma@ffe01000 { >>> compatible = "arm,pl330", "arm,primecell"; >>> reg = <0xffe01000 0x1000>; >>> interrupts = <0 104 4>, >>> <0 105 4>, >>> ... >>> #dma-cells = <1>; >>> #dma-channels = <8>; >>> #dma-requests = <32>; >>> clocks = <&l4_main_clk>; >>> clock-names = "apb_pclk"; >>> }; >>> >>> Perhaps I have the wrong designation for clock-names and the amba bus is >>> not able to pick up the correct clock? >> >> I have two ideas: >> 1. Is this really the clock for the DMA? If DMA is not used then >> disabling it should be OK. > > Yes, this is the clock for the DMA. Yeah, leaving this clock off is > fine, until the DMA gets used. Up until v4.0, SoCFPGA was not using the > DMA at all, but in v4.0, there was a patch to assign the UARTs to it's > DMA channel. > > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/arch/arm/boot/dts/socfpga.dtsi?id=78c03c7af89721bd8a4428408a8cc7b53972e4b8 > >> 2. Disabling the clock may effectively disable its parent or >> grandparent if there are not more users. Maybe some other driver needs >> these parents to be enabled? This was the issue for at least one >> similar error (on Exynos boards). >> > > I'll check up on these issues. When I was debugging this issue, the > l4_main_clk is only used by the DMA, so it was not getting turned on by > an other drivers. > Ah, it looks like perhaps there's a problem with the serial driver and suspend/resume? If disable CONFIG_PM, then the DMA seems to be working fine with the debug uart. It appears the DMA is getting suspended and doesn't get resumed. Dinh -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
2015-05-05 4:52 GMT+09:00 Dinh Nguyen <dinguyen@opensource.altera.com>: > On 05/04/2015 09:06 AM, Dinh Nguyen wrote: >> +CC Olof >> >> On 5/4/15 8:50 AM, Krzysztof Kozlowski wrote: >>> 2015-05-04 22:28 GMT+09:00 Dinh Nguyen <dinguyen@opensource.altera.com>: >>>> Hi Krzystof, >>>> >>>> On 5/4/15 12:30 AM, Krzysztof Kozlowski wrote: >>>>> 2015-05-04 13:28 GMT+09:00 <dinguyen@opensource.altera.com>: >>>>>> From: Dinh Nguyen <dinguyen@opensource.altera.com> >>>>>> >>>>>> Turn on the clock to the PL330 DMA if there is a clock node provided. >>>>> >>>>> Why? There is no explanation in the patch for this important question - why? >>>>> >>>>> Amba bus already does this and provide a wrapper function. >>>>> Additionally that would mess up with runtime PM and clock >>>>> enable/disable. >>>> >>>> I don't see the clock for the DMA getting turned on at all, which is why >>>> after the kernel has booted, the filesystem tries to open up a serial >>>> port using DMA and the system hangs. The failure is seen here: >>>> >>>> http://arm-soc.lixom.net/bootlogs/next/next-20150504/socfpga-arm-multi_v7_defconfig.html >>> >>> Thanks! >>> >>> The amba bus and pl330 should enable the clock and then disable it >>> after probing: >>> static int amba_probe(struct device *dev) >>> { >>> ... >>> ret = amba_get_enable_pclk(pcdev); >>> ... >>> >>> I wonder why do you think it is not enabled at all? >> >> I've checked it down to the register level that the gate for this clock >> does not get set. >> >>> >>>> >>>> This only happens with the multi_v7_defconfig, because the PL330 DMA is >>>> getting built into the kernel, while the socfpga_defconfig does not >>>> enable the PL330. >>> >>> It makes sense. If pl330 driver is not enabled then necessary clocks >>> are turned on by bootloader. Probing pl330 effectively disables the >>> clock (if DMA is not used). >>> >>>> The DTS for the socfpga platform looks like this: >>>> >>>> pdma: pdma@ffe01000 { >>>> compatible = "arm,pl330", "arm,primecell"; >>>> reg = <0xffe01000 0x1000>; >>>> interrupts = <0 104 4>, >>>> <0 105 4>, >>>> ... >>>> #dma-cells = <1>; >>>> #dma-channels = <8>; >>>> #dma-requests = <32>; >>>> clocks = <&l4_main_clk>; >>>> clock-names = "apb_pclk"; >>>> }; >>>> >>>> Perhaps I have the wrong designation for clock-names and the amba bus is >>>> not able to pick up the correct clock? >>> >>> I have two ideas: >>> 1. Is this really the clock for the DMA? If DMA is not used then >>> disabling it should be OK. >> >> Yes, this is the clock for the DMA. Yeah, leaving this clock off is >> fine, until the DMA gets used. Up until v4.0, SoCFPGA was not using the >> DMA at all, but in v4.0, there was a patch to assign the UARTs to it's >> DMA channel. >> >> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/arch/arm/boot/dts/socfpga.dtsi?id=78c03c7af89721bd8a4428408a8cc7b53972e4b8 >> >>> 2. Disabling the clock may effectively disable its parent or >>> grandparent if there are not more users. Maybe some other driver needs >>> these parents to be enabled? This was the issue for at least one >>> similar error (on Exynos boards). >>> >> >> I'll check up on these issues. When I was debugging this issue, the >> l4_main_clk is only used by the DMA, so it was not getting turned on by >> an other drivers. >> > > Ah, it looks like perhaps there's a problem with the serial driver and > suspend/resume? If disable CONFIG_PM, then the DMA seems to be working > fine with the debug uart. It appears the DMA is getting suspended and > doesn't get resumed. > You mean runtime PM suspend and resume or system sleep? During boot only the first one should happen. Could you test the DMA with dmatest? Disable the DMA in UART and compile with CONFIG_DMATEST. Syntax for testing is here: Documentation/dmaengine/dmatest.txt Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 05/04/2015 10:55 PM, Krzysztof Kozlowski wrote: > 2015-05-05 4:52 GMT+09:00 Dinh Nguyen <dinguyen@opensource.altera.com>: >> On 05/04/2015 09:06 AM, Dinh Nguyen wrote: >>> +CC Olof >>> >>> On 5/4/15 8:50 AM, Krzysztof Kozlowski wrote: >>>> 2015-05-04 22:28 GMT+09:00 Dinh Nguyen <dinguyen@opensource.altera.com>: >>>>> Hi Krzystof, >>>>> >>>>> On 5/4/15 12:30 AM, Krzysztof Kozlowski wrote: >>>>>> 2015-05-04 13:28 GMT+09:00 <dinguyen@opensource.altera.com>: >>>>>>> From: Dinh Nguyen <dinguyen@opensource.altera.com> >>>>>>> >>>>>>> Turn on the clock to the PL330 DMA if there is a clock node provided. >>>>>> >>>>>> Why? There is no explanation in the patch for this important question - why? >>>>>> >>>>>> Amba bus already does this and provide a wrapper function. >>>>>> Additionally that would mess up with runtime PM and clock >>>>>> enable/disable. >>>>> >>>>> I don't see the clock for the DMA getting turned on at all, which is why >>>>> after the kernel has booted, the filesystem tries to open up a serial >>>>> port using DMA and the system hangs. The failure is seen here: >>>>> >>>>> http://arm-soc.lixom.net/bootlogs/next/next-20150504/socfpga-arm-multi_v7_defconfig.html >>>> >>>> Thanks! >>>> >>>> The amba bus and pl330 should enable the clock and then disable it >>>> after probing: >>>> static int amba_probe(struct device *dev) >>>> { >>>> ... >>>> ret = amba_get_enable_pclk(pcdev); >>>> ... >>>> >>>> I wonder why do you think it is not enabled at all? >>> >>> I've checked it down to the register level that the gate for this clock >>> does not get set. >>> >>>> >>>>> >>>>> This only happens with the multi_v7_defconfig, because the PL330 DMA is >>>>> getting built into the kernel, while the socfpga_defconfig does not >>>>> enable the PL330. >>>> >>>> It makes sense. If pl330 driver is not enabled then necessary clocks >>>> are turned on by bootloader. Probing pl330 effectively disables the >>>> clock (if DMA is not used). >>>> >>>>> The DTS for the socfpga platform looks like this: >>>>> >>>>> pdma: pdma@ffe01000 { >>>>> compatible = "arm,pl330", "arm,primecell"; >>>>> reg = <0xffe01000 0x1000>; >>>>> interrupts = <0 104 4>, >>>>> <0 105 4>, >>>>> ... >>>>> #dma-cells = <1>; >>>>> #dma-channels = <8>; >>>>> #dma-requests = <32>; >>>>> clocks = <&l4_main_clk>; >>>>> clock-names = "apb_pclk"; >>>>> }; >>>>> >>>>> Perhaps I have the wrong designation for clock-names and the amba bus is >>>>> not able to pick up the correct clock? >>>> >>>> I have two ideas: >>>> 1. Is this really the clock for the DMA? If DMA is not used then >>>> disabling it should be OK. >>> >>> Yes, this is the clock for the DMA. Yeah, leaving this clock off is >>> fine, until the DMA gets used. Up until v4.0, SoCFPGA was not using the >>> DMA at all, but in v4.0, there was a patch to assign the UARTs to it's >>> DMA channel. >>> >>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/arch/arm/boot/dts/socfpga.dtsi?id=78c03c7af89721bd8a4428408a8cc7b53972e4b8 >>> >>>> 2. Disabling the clock may effectively disable its parent or >>>> grandparent if there are not more users. Maybe some other driver needs >>>> these parents to be enabled? This was the issue for at least one >>>> similar error (on Exynos boards). >>>> >>> >>> I'll check up on these issues. When I was debugging this issue, the >>> l4_main_clk is only used by the DMA, so it was not getting turned on by >>> an other drivers. >>> >> >> Ah, it looks like perhaps there's a problem with the serial driver and >> suspend/resume? If disable CONFIG_PM, then the DMA seems to be working >> fine with the debug uart. It appears the DMA is getting suspended and >> doesn't get resumed. >> > > You mean runtime PM suspend and resume or system sleep? During boot > only the first one should happen. It's runtime PM suspend/resume. > > Could you test the DMA with dmatest? Disable the DMA in UART and > compile with CONFIG_DMATEST. Syntax for testing is here: > Documentation/dmaengine/dmatest.txt > # echo Y > /sys/module/dmatest/parameters/run [ 93.143775] dmatest: Started 1 threads using dma0chan0 [ 93.149227] pm_generic_runtime_resume [ 93.153334] dmatest: Started 1 threads using dma0chan1 [ 93.159380] dmatest: Started 1 threads using dma0chan2 [ 93.165041] dmatest: Started 1 threads using dma0chan3 [ 93.170280] dmatest: Started 1 threads using dma0chan4 [ 93.175996] dmatest: Started 1 threads using dma0chan5 [ 93.181642] dmatest: Started 1 threads using dma0chan6 [ 93.188754] dmatest: dma0chan1-copy0: summary 10 tests, 0 failures 282 iops 2008 KB/s (0) [ 93.197091] dmatest: Started 1 threads using dma0chan7 [ 93.199353] dmatest: dma0chan3-copy0: summary 10 tests, 0 failures 297 iops 2260 KB/s (0) [ 93.205407] dmatest: dma0chan0-copy0: summary 10 tests, 0 failures 177 iops 1364 KB/s (0) [ 93.215599] dmatest: dma0chan2-copy0: summary 10 tests, 0 failures 196 iops 1450 KB/s (0) [ 93.219994] dmatest: dma0chan4-copy0: summary 10 tests, 0 failures 225 iops 1554 KB/s (0) [ 93.224322] dmatest: dma0chan5-copy0: summary 10 tests, 0 failures 231 iops 1948 KB/s (0) [ 93.230065] dmatest: dma0chan6-copy0: summary 10 tests, 0 failures 231 iops 1759 KB/s (0) [ 93.231251] dmatest: dma0chan7-copy0: summary 10 tests, 0 failures 298 iops 2331 KB/s (0) [ 93.243523] pm_generic_runtime_suspend root@socfpga_cyclone5:~# Dinh -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 05/05/2015 09:56 AM, Dinh Nguyen wrote: > On 05/04/2015 10:55 PM, Krzysztof Kozlowski wrote: >> 2015-05-05 4:52 GMT+09:00 Dinh Nguyen <dinguyen@opensource.altera.com>: >>> On 05/04/2015 09:06 AM, Dinh Nguyen wrote: >>>> +CC Olof >>>> >>>> On 5/4/15 8:50 AM, Krzysztof Kozlowski wrote: >>>>> 2015-05-04 22:28 GMT+09:00 Dinh Nguyen <dinguyen@opensource.altera.com>: >>>>>> Hi Krzystof, >>>>>> >>>>>> On 5/4/15 12:30 AM, Krzysztof Kozlowski wrote: >>>>>>> 2015-05-04 13:28 GMT+09:00 <dinguyen@opensource.altera.com>: >>>>>>>> From: Dinh Nguyen <dinguyen@opensource.altera.com> >>>>>>>> >>>>>>>> Turn on the clock to the PL330 DMA if there is a clock node provided. >>>>>>> >>>>>>> Why? There is no explanation in the patch for this important question - why? >>>>>>> >>>>>>> Amba bus already does this and provide a wrapper function. >>>>>>> Additionally that would mess up with runtime PM and clock >>>>>>> enable/disable. >>>>>> >>>>>> I don't see the clock for the DMA getting turned on at all, which is why >>>>>> after the kernel has booted, the filesystem tries to open up a serial >>>>>> port using DMA and the system hangs. The failure is seen here: >>>>>> >>>>>> http://arm-soc.lixom.net/bootlogs/next/next-20150504/socfpga-arm-multi_v7_defconfig.html >>>>> >>>>> Thanks! >>>>> >>>>> The amba bus and pl330 should enable the clock and then disable it >>>>> after probing: >>>>> static int amba_probe(struct device *dev) >>>>> { >>>>> ... >>>>> ret = amba_get_enable_pclk(pcdev); >>>>> ... >>>>> >>>>> I wonder why do you think it is not enabled at all? >>>> >>>> I've checked it down to the register level that the gate for this clock >>>> does not get set. >>>> >>>>> >>>>>> >>>>>> This only happens with the multi_v7_defconfig, because the PL330 DMA is >>>>>> getting built into the kernel, while the socfpga_defconfig does not >>>>>> enable the PL330. >>>>> >>>>> It makes sense. If pl330 driver is not enabled then necessary clocks >>>>> are turned on by bootloader. Probing pl330 effectively disables the >>>>> clock (if DMA is not used). >>>>> >>>>>> The DTS for the socfpga platform looks like this: >>>>>> >>>>>> pdma: pdma@ffe01000 { >>>>>> compatible = "arm,pl330", "arm,primecell"; >>>>>> reg = <0xffe01000 0x1000>; >>>>>> interrupts = <0 104 4>, >>>>>> <0 105 4>, >>>>>> ... >>>>>> #dma-cells = <1>; >>>>>> #dma-channels = <8>; >>>>>> #dma-requests = <32>; >>>>>> clocks = <&l4_main_clk>; >>>>>> clock-names = "apb_pclk"; >>>>>> }; >>>>>> >>>>>> Perhaps I have the wrong designation for clock-names and the amba bus is >>>>>> not able to pick up the correct clock? >>>>> >>>>> I have two ideas: >>>>> 1. Is this really the clock for the DMA? If DMA is not used then >>>>> disabling it should be OK. >>>> >>>> Yes, this is the clock for the DMA. Yeah, leaving this clock off is >>>> fine, until the DMA gets used. Up until v4.0, SoCFPGA was not using the >>>> DMA at all, but in v4.0, there was a patch to assign the UARTs to it's >>>> DMA channel. >>>> >>>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/arch/arm/boot/dts/socfpga.dtsi?id=78c03c7af89721bd8a4428408a8cc7b53972e4b8 >>>> >>>>> 2. Disabling the clock may effectively disable its parent or >>>>> grandparent if there are not more users. Maybe some other driver needs >>>>> these parents to be enabled? This was the issue for at least one >>>>> similar error (on Exynos boards). >>>>> >>>> >>>> I'll check up on these issues. When I was debugging this issue, the >>>> l4_main_clk is only used by the DMA, so it was not getting turned on by >>>> an other drivers. >>>> >>> >>> Ah, it looks like perhaps there's a problem with the serial driver and >>> suspend/resume? If disable CONFIG_PM, then the DMA seems to be working >>> fine with the debug uart. It appears the DMA is getting suspended and >>> doesn't get resumed. >>> >> >> You mean runtime PM suspend and resume or system sleep? During boot >> only the first one should happen. > > It's runtime PM suspend/resume. > >> >> Could you test the DMA with dmatest? Disable the DMA in UART and >> compile with CONFIG_DMATEST. Syntax for testing is here: >> Documentation/dmaengine/dmatest.txt >> > > # echo Y > /sys/module/dmatest/parameters/run > [ 93.143775] dmatest: Started 1 threads using dma0chan0 > [ 93.149227] pm_generic_runtime_resume > [ 93.153334] dmatest: Started 1 threads using dma0chan1 > [ 93.159380] dmatest: Started 1 threads using dma0chan2 > [ 93.165041] dmatest: Started 1 threads using dma0chan3 > [ 93.170280] dmatest: Started 1 threads using dma0chan4 > [ 93.175996] dmatest: Started 1 threads using dma0chan5 > [ 93.181642] dmatest: Started 1 threads using dma0chan6 > [ 93.188754] dmatest: dma0chan1-copy0: summary 10 tests, 0 failures > 282 iops 2008 KB/s (0) > [ 93.197091] dmatest: Started 1 threads using dma0chan7 > [ 93.199353] dmatest: dma0chan3-copy0: summary 10 tests, 0 failures > 297 iops 2260 KB/s (0) > [ 93.205407] dmatest: dma0chan0-copy0: summary 10 tests, 0 failures > 177 iops 1364 KB/s (0) > [ 93.215599] dmatest: dma0chan2-copy0: summary 10 tests, 0 failures > 196 iops 1450 KB/s (0) > [ 93.219994] dmatest: dma0chan4-copy0: summary 10 tests, 0 failures > 225 iops 1554 KB/s (0) > [ 93.224322] dmatest: dma0chan5-copy0: summary 10 tests, 0 failures > 231 iops 1948 KB/s (0) > [ 93.230065] dmatest: dma0chan6-copy0: summary 10 tests, 0 failures > 231 iops 1759 KB/s (0) > [ 93.231251] dmatest: dma0chan7-copy0: summary 10 tests, 0 failures > 298 iops 2331 KB/s (0) > [ 93.243523] pm_generic_runtime_suspend > root@socfpga_cyclone5:~# > If I run dmatest the 2nd time it fails. It does not look like amba_pm_runtime_resume() is getting called to turn on the clocks on the subsequent tries. Dinh -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Krzysztof, On 05/05/2015 02:22 PM, Dinh Nguyen wrote: > On 05/05/2015 09:56 AM, Dinh Nguyen wrote: >> On 05/04/2015 10:55 PM, Krzysztof Kozlowski wrote: >>> 2015-05-05 4:52 GMT+09:00 Dinh Nguyen <dinguyen@opensource.altera.com>: >>>> On 05/04/2015 09:06 AM, Dinh Nguyen wrote: >>>>> +CC Olof >>>>> >>>>> On 5/4/15 8:50 AM, Krzysztof Kozlowski wrote: >>>>>> 2015-05-04 22:28 GMT+09:00 Dinh Nguyen <dinguyen@opensource.altera.com>: >>>>>>> Hi Krzystof, >>>>>>> >>>>>>> On 5/4/15 12:30 AM, Krzysztof Kozlowski wrote: >>>>>>>> 2015-05-04 13:28 GMT+09:00 <dinguyen@opensource.altera.com>: >>>>>>>>> From: Dinh Nguyen <dinguyen@opensource.altera.com> >>>>>>>>> >>>>>>>>> Turn on the clock to the PL330 DMA if there is a clock node provided. >>>>>>>> >>>>>>>> Why? There is no explanation in the patch for this important question - why? >>>>>>>> >>>>>>>> Amba bus already does this and provide a wrapper function. >>>>>>>> Additionally that would mess up with runtime PM and clock >>>>>>>> enable/disable. >>>>>>> >>>>>>> I don't see the clock for the DMA getting turned on at all, which is why >>>>>>> after the kernel has booted, the filesystem tries to open up a serial >>>>>>> port using DMA and the system hangs. The failure is seen here: >>>>>>> >>>>>>> http://arm-soc.lixom.net/bootlogs/next/next-20150504/socfpga-arm-multi_v7_defconfig.html >>>>>> >>>>>> Thanks! >>>>>> >>>>>> The amba bus and pl330 should enable the clock and then disable it >>>>>> after probing: >>>>>> static int amba_probe(struct device *dev) >>>>>> { >>>>>> ... >>>>>> ret = amba_get_enable_pclk(pcdev); >>>>>> ... >>>>>> >>>>>> I wonder why do you think it is not enabled at all? >>>>> >>>>> I've checked it down to the register level that the gate for this clock >>>>> does not get set. >>>>> >>>>>> >>>>>>> >>>>>>> This only happens with the multi_v7_defconfig, because the PL330 DMA is >>>>>>> getting built into the kernel, while the socfpga_defconfig does not >>>>>>> enable the PL330. >>>>>> >>>>>> It makes sense. If pl330 driver is not enabled then necessary clocks >>>>>> are turned on by bootloader. Probing pl330 effectively disables the >>>>>> clock (if DMA is not used). >>>>>> >>>>>>> The DTS for the socfpga platform looks like this: >>>>>>> >>>>>>> pdma: pdma@ffe01000 { >>>>>>> compatible = "arm,pl330", "arm,primecell"; >>>>>>> reg = <0xffe01000 0x1000>; >>>>>>> interrupts = <0 104 4>, >>>>>>> <0 105 4>, >>>>>>> ... >>>>>>> #dma-cells = <1>; >>>>>>> #dma-channels = <8>; >>>>>>> #dma-requests = <32>; >>>>>>> clocks = <&l4_main_clk>; >>>>>>> clock-names = "apb_pclk"; >>>>>>> }; >>>>>>> >>>>>>> Perhaps I have the wrong designation for clock-names and the amba bus is >>>>>>> not able to pick up the correct clock? >>>>>> >>>>>> I have two ideas: >>>>>> 1. Is this really the clock for the DMA? If DMA is not used then >>>>>> disabling it should be OK. >>>>> >>>>> Yes, this is the clock for the DMA. Yeah, leaving this clock off is >>>>> fine, until the DMA gets used. Up until v4.0, SoCFPGA was not using the >>>>> DMA at all, but in v4.0, there was a patch to assign the UARTs to it's >>>>> DMA channel. >>>>> >>>>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/arch/arm/boot/dts/socfpga.dtsi?id=78c03c7af89721bd8a4428408a8cc7b53972e4b8 >>>>> >>>>>> 2. Disabling the clock may effectively disable its parent or >>>>>> grandparent if there are not more users. Maybe some other driver needs >>>>>> these parents to be enabled? This was the issue for at least one >>>>>> similar error (on Exynos boards). >>>>>> >>>>> >>>>> I'll check up on these issues. When I was debugging this issue, the >>>>> l4_main_clk is only used by the DMA, so it was not getting turned on by >>>>> an other drivers. >>>>> >>>> >>>> Ah, it looks like perhaps there's a problem with the serial driver and >>>> suspend/resume? If disable CONFIG_PM, then the DMA seems to be working >>>> fine with the debug uart. It appears the DMA is getting suspended and >>>> doesn't get resumed. >>>> >>> >>> You mean runtime PM suspend and resume or system sleep? During boot >>> only the first one should happen. >> >> It's runtime PM suspend/resume. >> >>> >>> Could you test the DMA with dmatest? Disable the DMA in UART and >>> compile with CONFIG_DMATEST. Syntax for testing is here: >>> Documentation/dmaengine/dmatest.txt >>> >> >> # echo Y > /sys/module/dmatest/parameters/run >> [ 93.143775] dmatest: Started 1 threads using dma0chan0 >> [ 93.149227] pm_generic_runtime_resume >> [ 93.153334] dmatest: Started 1 threads using dma0chan1 >> [ 93.159380] dmatest: Started 1 threads using dma0chan2 >> [ 93.165041] dmatest: Started 1 threads using dma0chan3 >> [ 93.170280] dmatest: Started 1 threads using dma0chan4 >> [ 93.175996] dmatest: Started 1 threads using dma0chan5 >> [ 93.181642] dmatest: Started 1 threads using dma0chan6 >> [ 93.188754] dmatest: dma0chan1-copy0: summary 10 tests, 0 failures >> 282 iops 2008 KB/s (0) >> [ 93.197091] dmatest: Started 1 threads using dma0chan7 >> [ 93.199353] dmatest: dma0chan3-copy0: summary 10 tests, 0 failures >> 297 iops 2260 KB/s (0) >> [ 93.205407] dmatest: dma0chan0-copy0: summary 10 tests, 0 failures >> 177 iops 1364 KB/s (0) >> [ 93.215599] dmatest: dma0chan2-copy0: summary 10 tests, 0 failures >> 196 iops 1450 KB/s (0) >> [ 93.219994] dmatest: dma0chan4-copy0: summary 10 tests, 0 failures >> 225 iops 1554 KB/s (0) >> [ 93.224322] dmatest: dma0chan5-copy0: summary 10 tests, 0 failures >> 231 iops 1948 KB/s (0) >> [ 93.230065] dmatest: dma0chan6-copy0: summary 10 tests, 0 failures >> 231 iops 1759 KB/s (0) >> [ 93.231251] dmatest: dma0chan7-copy0: summary 10 tests, 0 failures >> 298 iops 2331 KB/s (0) >> [ 93.243523] pm_generic_runtime_suspend >> root@socfpga_cyclone5:~# >> > > If I run dmatest the 2nd time it fails. It does not look like > amba_pm_runtime_resume() is getting called to turn on the clocks on the > subsequent tries. > I managed to track this down the call dmaengine_terminate_all(), which then calls into pl330_terminate_all(). So in pl330_terminate_all(), it call _stop, which hits a infinite loop, UNTIL. But since the amba_pm_runtime_resume() has not been called yet, the clock is turned off. Thus, we're stuck in an infinite loop. I'm not sure what would be right approach to fix this? Thanks, Dinh -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 21.05.2015 05:30, Dinh Nguyen wrote: > Hi Krzysztof, > > On 05/05/2015 02:22 PM, Dinh Nguyen wrote: >> On 05/05/2015 09:56 AM, Dinh Nguyen wrote: >>> On 05/04/2015 10:55 PM, Krzysztof Kozlowski wrote: >>>> 2015-05-05 4:52 GMT+09:00 Dinh Nguyen <dinguyen@opensource.altera.com>: >>>>> On 05/04/2015 09:06 AM, Dinh Nguyen wrote: >>>>>> +CC Olof >>>>>> >>>>>> On 5/4/15 8:50 AM, Krzysztof Kozlowski wrote: >>>>>>> 2015-05-04 22:28 GMT+09:00 Dinh Nguyen <dinguyen@opensource.altera.com>: >>>>>>>> Hi Krzystof, >>>>>>>> >>>>>>>> On 5/4/15 12:30 AM, Krzysztof Kozlowski wrote: >>>>>>>>> 2015-05-04 13:28 GMT+09:00 <dinguyen@opensource.altera.com>: >>>>>>>>>> From: Dinh Nguyen <dinguyen@opensource.altera.com> >>>>>>>>>> >>>>>>>>>> Turn on the clock to the PL330 DMA if there is a clock node provided. >>>>>>>>> >>>>>>>>> Why? There is no explanation in the patch for this important question - why? >>>>>>>>> >>>>>>>>> Amba bus already does this and provide a wrapper function. >>>>>>>>> Additionally that would mess up with runtime PM and clock >>>>>>>>> enable/disable. >>>>>>>> >>>>>>>> I don't see the clock for the DMA getting turned on at all, which is why >>>>>>>> after the kernel has booted, the filesystem tries to open up a serial >>>>>>>> port using DMA and the system hangs. The failure is seen here: >>>>>>>> >>>>>>>> http://arm-soc.lixom.net/bootlogs/next/next-20150504/socfpga-arm-multi_v7_defconfig.html >>>>>>> >>>>>>> Thanks! >>>>>>> >>>>>>> The amba bus and pl330 should enable the clock and then disable it >>>>>>> after probing: >>>>>>> static int amba_probe(struct device *dev) >>>>>>> { >>>>>>> ... >>>>>>> ret = amba_get_enable_pclk(pcdev); >>>>>>> ... >>>>>>> >>>>>>> I wonder why do you think it is not enabled at all? >>>>>> >>>>>> I've checked it down to the register level that the gate for this clock >>>>>> does not get set. >>>>>> >>>>>>> >>>>>>>> >>>>>>>> This only happens with the multi_v7_defconfig, because the PL330 DMA is >>>>>>>> getting built into the kernel, while the socfpga_defconfig does not >>>>>>>> enable the PL330. >>>>>>> >>>>>>> It makes sense. If pl330 driver is not enabled then necessary clocks >>>>>>> are turned on by bootloader. Probing pl330 effectively disables the >>>>>>> clock (if DMA is not used). >>>>>>> >>>>>>>> The DTS for the socfpga platform looks like this: >>>>>>>> >>>>>>>> pdma: pdma@ffe01000 { >>>>>>>> compatible = "arm,pl330", "arm,primecell"; >>>>>>>> reg = <0xffe01000 0x1000>; >>>>>>>> interrupts = <0 104 4>, >>>>>>>> <0 105 4>, >>>>>>>> ... >>>>>>>> #dma-cells = <1>; >>>>>>>> #dma-channels = <8>; >>>>>>>> #dma-requests = <32>; >>>>>>>> clocks = <&l4_main_clk>; >>>>>>>> clock-names = "apb_pclk"; >>>>>>>> }; >>>>>>>> >>>>>>>> Perhaps I have the wrong designation for clock-names and the amba bus is >>>>>>>> not able to pick up the correct clock? >>>>>>> >>>>>>> I have two ideas: >>>>>>> 1. Is this really the clock for the DMA? If DMA is not used then >>>>>>> disabling it should be OK. >>>>>> >>>>>> Yes, this is the clock for the DMA. Yeah, leaving this clock off is >>>>>> fine, until the DMA gets used. Up until v4.0, SoCFPGA was not using the >>>>>> DMA at all, but in v4.0, there was a patch to assign the UARTs to it's >>>>>> DMA channel. >>>>>> >>>>>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/arch/arm/boot/dts/socfpga.dtsi?id=78c03c7af89721bd8a4428408a8cc7b53972e4b8 >>>>>> >>>>>>> 2. Disabling the clock may effectively disable its parent or >>>>>>> grandparent if there are not more users. Maybe some other driver needs >>>>>>> these parents to be enabled? This was the issue for at least one >>>>>>> similar error (on Exynos boards). >>>>>>> >>>>>> >>>>>> I'll check up on these issues. When I was debugging this issue, the >>>>>> l4_main_clk is only used by the DMA, so it was not getting turned on by >>>>>> an other drivers. >>>>>> >>>>> >>>>> Ah, it looks like perhaps there's a problem with the serial driver and >>>>> suspend/resume? If disable CONFIG_PM, then the DMA seems to be working >>>>> fine with the debug uart. It appears the DMA is getting suspended and >>>>> doesn't get resumed. >>>>> >>>> >>>> You mean runtime PM suspend and resume or system sleep? During boot >>>> only the first one should happen. >>> >>> It's runtime PM suspend/resume. >>> >>>> >>>> Could you test the DMA with dmatest? Disable the DMA in UART and >>>> compile with CONFIG_DMATEST. Syntax for testing is here: >>>> Documentation/dmaengine/dmatest.txt >>>> >>> >>> # echo Y > /sys/module/dmatest/parameters/run >>> [ 93.143775] dmatest: Started 1 threads using dma0chan0 >>> [ 93.149227] pm_generic_runtime_resume >>> [ 93.153334] dmatest: Started 1 threads using dma0chan1 >>> [ 93.159380] dmatest: Started 1 threads using dma0chan2 >>> [ 93.165041] dmatest: Started 1 threads using dma0chan3 >>> [ 93.170280] dmatest: Started 1 threads using dma0chan4 >>> [ 93.175996] dmatest: Started 1 threads using dma0chan5 >>> [ 93.181642] dmatest: Started 1 threads using dma0chan6 >>> [ 93.188754] dmatest: dma0chan1-copy0: summary 10 tests, 0 failures >>> 282 iops 2008 KB/s (0) >>> [ 93.197091] dmatest: Started 1 threads using dma0chan7 >>> [ 93.199353] dmatest: dma0chan3-copy0: summary 10 tests, 0 failures >>> 297 iops 2260 KB/s (0) >>> [ 93.205407] dmatest: dma0chan0-copy0: summary 10 tests, 0 failures >>> 177 iops 1364 KB/s (0) >>> [ 93.215599] dmatest: dma0chan2-copy0: summary 10 tests, 0 failures >>> 196 iops 1450 KB/s (0) >>> [ 93.219994] dmatest: dma0chan4-copy0: summary 10 tests, 0 failures >>> 225 iops 1554 KB/s (0) >>> [ 93.224322] dmatest: dma0chan5-copy0: summary 10 tests, 0 failures >>> 231 iops 1948 KB/s (0) >>> [ 93.230065] dmatest: dma0chan6-copy0: summary 10 tests, 0 failures >>> 231 iops 1759 KB/s (0) >>> [ 93.231251] dmatest: dma0chan7-copy0: summary 10 tests, 0 failures >>> 298 iops 2331 KB/s (0) >>> [ 93.243523] pm_generic_runtime_suspend >>> root@socfpga_cyclone5:~# >>> >> >> If I run dmatest the 2nd time it fails. It does not look like >> amba_pm_runtime_resume() is getting called to turn on the clocks on the >> subsequent tries. >> > > > I managed to track this down the call dmaengine_terminate_all(), which > then calls into pl330_terminate_all(). So in pl330_terminate_all(), it > call _stop, which hits a infinite loop, UNTIL. But since the > amba_pm_runtime_resume() has not been called yet, the clock is turned > off. Thus, we're stuck in an infinite loop. > > I'm not sure what would be right approach to fix this? Good catch. I confirmed that device is not runtime resumed. I wonder why it works in my case (pl330 on Exynos4412)... Anyway I have an idea to fix it. I'll send a patch. Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 21.05.2015 09:16, Krzysztof Kozlowski wrote: > On 21.05.2015 05:30, Dinh Nguyen wrote: >> Hi Krzysztof, >> >> On 05/05/2015 02:22 PM, Dinh Nguyen wrote: >>> On 05/05/2015 09:56 AM, Dinh Nguyen wrote: >>>> On 05/04/2015 10:55 PM, Krzysztof Kozlowski wrote: >>>>> 2015-05-05 4:52 GMT+09:00 Dinh Nguyen <dinguyen@opensource.altera.com>: >>>>>> On 05/04/2015 09:06 AM, Dinh Nguyen wrote: >>>>>>> +CC Olof >>>>>>> >>>>>>> On 5/4/15 8:50 AM, Krzysztof Kozlowski wrote: >>>>>>>> 2015-05-04 22:28 GMT+09:00 Dinh Nguyen <dinguyen@opensource.altera.com>: >>>>>>>>> Hi Krzystof, >>>>>>>>> >>>>>>>>> On 5/4/15 12:30 AM, Krzysztof Kozlowski wrote: >>>>>>>>>> 2015-05-04 13:28 GMT+09:00 <dinguyen@opensource.altera.com>: >>>>>>>>>>> From: Dinh Nguyen <dinguyen@opensource.altera.com> >>>>>>>>>>> >>>>>>>>>>> Turn on the clock to the PL330 DMA if there is a clock node provided. >>>>>>>>>> >>>>>>>>>> Why? There is no explanation in the patch for this important question - why? >>>>>>>>>> >>>>>>>>>> Amba bus already does this and provide a wrapper function. >>>>>>>>>> Additionally that would mess up with runtime PM and clock >>>>>>>>>> enable/disable. >>>>>>>>> >>>>>>>>> I don't see the clock for the DMA getting turned on at all, which is why >>>>>>>>> after the kernel has booted, the filesystem tries to open up a serial >>>>>>>>> port using DMA and the system hangs. The failure is seen here: >>>>>>>>> >>>>>>>>> http://arm-soc.lixom.net/bootlogs/next/next-20150504/socfpga-arm-multi_v7_defconfig.html >>>>>>>> >>>>>>>> Thanks! >>>>>>>> >>>>>>>> The amba bus and pl330 should enable the clock and then disable it >>>>>>>> after probing: >>>>>>>> static int amba_probe(struct device *dev) >>>>>>>> { >>>>>>>> ... >>>>>>>> ret = amba_get_enable_pclk(pcdev); >>>>>>>> ... >>>>>>>> >>>>>>>> I wonder why do you think it is not enabled at all? >>>>>>> >>>>>>> I've checked it down to the register level that the gate for this clock >>>>>>> does not get set. >>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>>> This only happens with the multi_v7_defconfig, because the PL330 DMA is >>>>>>>>> getting built into the kernel, while the socfpga_defconfig does not >>>>>>>>> enable the PL330. >>>>>>>> >>>>>>>> It makes sense. If pl330 driver is not enabled then necessary clocks >>>>>>>> are turned on by bootloader. Probing pl330 effectively disables the >>>>>>>> clock (if DMA is not used). >>>>>>>> >>>>>>>>> The DTS for the socfpga platform looks like this: >>>>>>>>> >>>>>>>>> pdma: pdma@ffe01000 { >>>>>>>>> compatible = "arm,pl330", "arm,primecell"; >>>>>>>>> reg = <0xffe01000 0x1000>; >>>>>>>>> interrupts = <0 104 4>, >>>>>>>>> <0 105 4>, >>>>>>>>> ... >>>>>>>>> #dma-cells = <1>; >>>>>>>>> #dma-channels = <8>; >>>>>>>>> #dma-requests = <32>; >>>>>>>>> clocks = <&l4_main_clk>; >>>>>>>>> clock-names = "apb_pclk"; >>>>>>>>> }; >>>>>>>>> >>>>>>>>> Perhaps I have the wrong designation for clock-names and the amba bus is >>>>>>>>> not able to pick up the correct clock? >>>>>>>> >>>>>>>> I have two ideas: >>>>>>>> 1. Is this really the clock for the DMA? If DMA is not used then >>>>>>>> disabling it should be OK. >>>>>>> >>>>>>> Yes, this is the clock for the DMA. Yeah, leaving this clock off is >>>>>>> fine, until the DMA gets used. Up until v4.0, SoCFPGA was not using the >>>>>>> DMA at all, but in v4.0, there was a patch to assign the UARTs to it's >>>>>>> DMA channel. >>>>>>> >>>>>>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/arch/arm/boot/dts/socfpga.dtsi?id=78c03c7af89721bd8a4428408a8cc7b53972e4b8 >>>>>>> >>>>>>>> 2. Disabling the clock may effectively disable its parent or >>>>>>>> grandparent if there are not more users. Maybe some other driver needs >>>>>>>> these parents to be enabled? This was the issue for at least one >>>>>>>> similar error (on Exynos boards). >>>>>>>> >>>>>>> >>>>>>> I'll check up on these issues. When I was debugging this issue, the >>>>>>> l4_main_clk is only used by the DMA, so it was not getting turned on by >>>>>>> an other drivers. >>>>>>> >>>>>> >>>>>> Ah, it looks like perhaps there's a problem with the serial driver and >>>>>> suspend/resume? If disable CONFIG_PM, then the DMA seems to be working >>>>>> fine with the debug uart. It appears the DMA is getting suspended and >>>>>> doesn't get resumed. >>>>>> >>>>> >>>>> You mean runtime PM suspend and resume or system sleep? During boot >>>>> only the first one should happen. >>>> >>>> It's runtime PM suspend/resume. >>>> >>>>> >>>>> Could you test the DMA with dmatest? Disable the DMA in UART and >>>>> compile with CONFIG_DMATEST. Syntax for testing is here: >>>>> Documentation/dmaengine/dmatest.txt >>>>> >>>> >>>> # echo Y > /sys/module/dmatest/parameters/run >>>> [ 93.143775] dmatest: Started 1 threads using dma0chan0 >>>> [ 93.149227] pm_generic_runtime_resume >>>> [ 93.153334] dmatest: Started 1 threads using dma0chan1 >>>> [ 93.159380] dmatest: Started 1 threads using dma0chan2 >>>> [ 93.165041] dmatest: Started 1 threads using dma0chan3 >>>> [ 93.170280] dmatest: Started 1 threads using dma0chan4 >>>> [ 93.175996] dmatest: Started 1 threads using dma0chan5 >>>> [ 93.181642] dmatest: Started 1 threads using dma0chan6 >>>> [ 93.188754] dmatest: dma0chan1-copy0: summary 10 tests, 0 failures >>>> 282 iops 2008 KB/s (0) >>>> [ 93.197091] dmatest: Started 1 threads using dma0chan7 >>>> [ 93.199353] dmatest: dma0chan3-copy0: summary 10 tests, 0 failures >>>> 297 iops 2260 KB/s (0) >>>> [ 93.205407] dmatest: dma0chan0-copy0: summary 10 tests, 0 failures >>>> 177 iops 1364 KB/s (0) >>>> [ 93.215599] dmatest: dma0chan2-copy0: summary 10 tests, 0 failures >>>> 196 iops 1450 KB/s (0) >>>> [ 93.219994] dmatest: dma0chan4-copy0: summary 10 tests, 0 failures >>>> 225 iops 1554 KB/s (0) >>>> [ 93.224322] dmatest: dma0chan5-copy0: summary 10 tests, 0 failures >>>> 231 iops 1948 KB/s (0) >>>> [ 93.230065] dmatest: dma0chan6-copy0: summary 10 tests, 0 failures >>>> 231 iops 1759 KB/s (0) >>>> [ 93.231251] dmatest: dma0chan7-copy0: summary 10 tests, 0 failures >>>> 298 iops 2331 KB/s (0) >>>> [ 93.243523] pm_generic_runtime_suspend >>>> root@socfpga_cyclone5:~# >>>> >>> >>> If I run dmatest the 2nd time it fails. It does not look like >>> amba_pm_runtime_resume() is getting called to turn on the clocks on the >>> subsequent tries. >>> >> >> >> I managed to track this down the call dmaengine_terminate_all(), which >> then calls into pl330_terminate_all(). So in pl330_terminate_all(), it >> call _stop, which hits a infinite loop, UNTIL. But since the >> amba_pm_runtime_resume() has not been called yet, the clock is turned >> off. Thus, we're stuck in an infinite loop. >> >> I'm not sure what would be right approach to fix this? > > Good catch. I confirmed that device is not runtime resumed. I wonder why > it works in my case (pl330 on Exynos4412)... > > Anyway I have an idea to fix it. I'll send a patch. I sent a patch. Could you test on your board and confirm that this fixes the issue? Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 05/20/2015 07:35 PM, Krzysztof Kozlowski wrote: > On 21.05.2015 09:16, Krzysztof Kozlowski wrote: >> On 21.05.2015 05:30, Dinh Nguyen wrote: >>> Hi Krzysztof, >>> >>> On 05/05/2015 02:22 PM, Dinh Nguyen wrote: >>>> On 05/05/2015 09:56 AM, Dinh Nguyen wrote: >>>>> On 05/04/2015 10:55 PM, Krzysztof Kozlowski wrote: >>>>>> 2015-05-05 4:52 GMT+09:00 Dinh Nguyen <dinguyen@opensource.altera.com>: >>>>>>> On 05/04/2015 09:06 AM, Dinh Nguyen wrote: >>>>>>>> +CC Olof >>>>>>>> >>>>>>>> On 5/4/15 8:50 AM, Krzysztof Kozlowski wrote: >>>>>>>>> 2015-05-04 22:28 GMT+09:00 Dinh Nguyen <dinguyen@opensource.altera.com>: >>>>>>>>>> Hi Krzystof, >>>>>>>>>> >>>>>>>>>> On 5/4/15 12:30 AM, Krzysztof Kozlowski wrote: >>>>>>>>>>> 2015-05-04 13:28 GMT+09:00 <dinguyen@opensource.altera.com>: >>>>>>>>>>>> From: Dinh Nguyen <dinguyen@opensource.altera.com> >>>>>>>>>>>> >>>>>>>>>>>> Turn on the clock to the PL330 DMA if there is a clock node provided. >>>>>>>>>>> >>>>>>>>>>> Why? There is no explanation in the patch for this important question - why? >>>>>>>>>>> >>>>>>>>>>> Amba bus already does this and provide a wrapper function. >>>>>>>>>>> Additionally that would mess up with runtime PM and clock >>>>>>>>>>> enable/disable. >>>>>>>>>> >>>>>>>>>> I don't see the clock for the DMA getting turned on at all, which is why >>>>>>>>>> after the kernel has booted, the filesystem tries to open up a serial >>>>>>>>>> port using DMA and the system hangs. The failure is seen here: >>>>>>>>>> >>>>>>>>>> http://arm-soc.lixom.net/bootlogs/next/next-20150504/socfpga-arm-multi_v7_defconfig.html >>>>>>>>> >>>>>>>>> Thanks! >>>>>>>>> >>>>>>>>> The amba bus and pl330 should enable the clock and then disable it >>>>>>>>> after probing: >>>>>>>>> static int amba_probe(struct device *dev) >>>>>>>>> { >>>>>>>>> ... >>>>>>>>> ret = amba_get_enable_pclk(pcdev); >>>>>>>>> ... >>>>>>>>> >>>>>>>>> I wonder why do you think it is not enabled at all? >>>>>>>> >>>>>>>> I've checked it down to the register level that the gate for this clock >>>>>>>> does not get set. >>>>>>>> >>>>>>>>> >>>>>>>>>> >>>>>>>>>> This only happens with the multi_v7_defconfig, because the PL330 DMA is >>>>>>>>>> getting built into the kernel, while the socfpga_defconfig does not >>>>>>>>>> enable the PL330. >>>>>>>>> >>>>>>>>> It makes sense. If pl330 driver is not enabled then necessary clocks >>>>>>>>> are turned on by bootloader. Probing pl330 effectively disables the >>>>>>>>> clock (if DMA is not used). >>>>>>>>> >>>>>>>>>> The DTS for the socfpga platform looks like this: >>>>>>>>>> >>>>>>>>>> pdma: pdma@ffe01000 { >>>>>>>>>> compatible = "arm,pl330", "arm,primecell"; >>>>>>>>>> reg = <0xffe01000 0x1000>; >>>>>>>>>> interrupts = <0 104 4>, >>>>>>>>>> <0 105 4>, >>>>>>>>>> ... >>>>>>>>>> #dma-cells = <1>; >>>>>>>>>> #dma-channels = <8>; >>>>>>>>>> #dma-requests = <32>; >>>>>>>>>> clocks = <&l4_main_clk>; >>>>>>>>>> clock-names = "apb_pclk"; >>>>>>>>>> }; >>>>>>>>>> >>>>>>>>>> Perhaps I have the wrong designation for clock-names and the amba bus is >>>>>>>>>> not able to pick up the correct clock? >>>>>>>>> >>>>>>>>> I have two ideas: >>>>>>>>> 1. Is this really the clock for the DMA? If DMA is not used then >>>>>>>>> disabling it should be OK. >>>>>>>> >>>>>>>> Yes, this is the clock for the DMA. Yeah, leaving this clock off is >>>>>>>> fine, until the DMA gets used. Up until v4.0, SoCFPGA was not using the >>>>>>>> DMA at all, but in v4.0, there was a patch to assign the UARTs to it's >>>>>>>> DMA channel. >>>>>>>> >>>>>>>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/arch/arm/boot/dts/socfpga.dtsi?id=78c03c7af89721bd8a4428408a8cc7b53972e4b8 >>>>>>>> >>>>>>>>> 2. Disabling the clock may effectively disable its parent or >>>>>>>>> grandparent if there are not more users. Maybe some other driver needs >>>>>>>>> these parents to be enabled? This was the issue for at least one >>>>>>>>> similar error (on Exynos boards). >>>>>>>>> >>>>>>>> >>>>>>>> I'll check up on these issues. When I was debugging this issue, the >>>>>>>> l4_main_clk is only used by the DMA, so it was not getting turned on by >>>>>>>> an other drivers. >>>>>>>> >>>>>>> >>>>>>> Ah, it looks like perhaps there's a problem with the serial driver and >>>>>>> suspend/resume? If disable CONFIG_PM, then the DMA seems to be working >>>>>>> fine with the debug uart. It appears the DMA is getting suspended and >>>>>>> doesn't get resumed. >>>>>>> >>>>>> >>>>>> You mean runtime PM suspend and resume or system sleep? During boot >>>>>> only the first one should happen. >>>>> >>>>> It's runtime PM suspend/resume. >>>>> >>>>>> >>>>>> Could you test the DMA with dmatest? Disable the DMA in UART and >>>>>> compile with CONFIG_DMATEST. Syntax for testing is here: >>>>>> Documentation/dmaengine/dmatest.txt >>>>>> >>>>> >>>>> # echo Y > /sys/module/dmatest/parameters/run >>>>> [ 93.143775] dmatest: Started 1 threads using dma0chan0 >>>>> [ 93.149227] pm_generic_runtime_resume >>>>> [ 93.153334] dmatest: Started 1 threads using dma0chan1 >>>>> [ 93.159380] dmatest: Started 1 threads using dma0chan2 >>>>> [ 93.165041] dmatest: Started 1 threads using dma0chan3 >>>>> [ 93.170280] dmatest: Started 1 threads using dma0chan4 >>>>> [ 93.175996] dmatest: Started 1 threads using dma0chan5 >>>>> [ 93.181642] dmatest: Started 1 threads using dma0chan6 >>>>> [ 93.188754] dmatest: dma0chan1-copy0: summary 10 tests, 0 failures >>>>> 282 iops 2008 KB/s (0) >>>>> [ 93.197091] dmatest: Started 1 threads using dma0chan7 >>>>> [ 93.199353] dmatest: dma0chan3-copy0: summary 10 tests, 0 failures >>>>> 297 iops 2260 KB/s (0) >>>>> [ 93.205407] dmatest: dma0chan0-copy0: summary 10 tests, 0 failures >>>>> 177 iops 1364 KB/s (0) >>>>> [ 93.215599] dmatest: dma0chan2-copy0: summary 10 tests, 0 failures >>>>> 196 iops 1450 KB/s (0) >>>>> [ 93.219994] dmatest: dma0chan4-copy0: summary 10 tests, 0 failures >>>>> 225 iops 1554 KB/s (0) >>>>> [ 93.224322] dmatest: dma0chan5-copy0: summary 10 tests, 0 failures >>>>> 231 iops 1948 KB/s (0) >>>>> [ 93.230065] dmatest: dma0chan6-copy0: summary 10 tests, 0 failures >>>>> 231 iops 1759 KB/s (0) >>>>> [ 93.231251] dmatest: dma0chan7-copy0: summary 10 tests, 0 failures >>>>> 298 iops 2331 KB/s (0) >>>>> [ 93.243523] pm_generic_runtime_suspend >>>>> root@socfpga_cyclone5:~# >>>>> >>>> >>>> If I run dmatest the 2nd time it fails. It does not look like >>>> amba_pm_runtime_resume() is getting called to turn on the clocks on the >>>> subsequent tries. >>>> >>> >>> >>> I managed to track this down the call dmaengine_terminate_all(), which >>> then calls into pl330_terminate_all(). So in pl330_terminate_all(), it >>> call _stop, which hits a infinite loop, UNTIL. But since the >>> amba_pm_runtime_resume() has not been called yet, the clock is turned >>> off. Thus, we're stuck in an infinite loop. >>> >>> I'm not sure what would be right approach to fix this? >> >> Good catch. I confirmed that device is not runtime resumed. I wonder why >> it works in my case (pl330 on Exynos4412)... >> >> Anyway I have an idea to fix it. I'll send a patch. > > I sent a patch. Could you test on your board and confirm that this fixes > the issue? > Thanks alot for the patch! It does indeed fixes the issue for me. 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diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index 0e1f567..82eb641 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2894,6 +2894,10 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id) adev->dev.dma_parms = &pl330->dma_parms; + adev->pclk = devm_clk_get(&adev->dev, "apb_pclk"); + if (adev->pclk) + clk_prepare_enable(adev->pclk); + /* * This is the limit for transfers with a buswidth of 1, larger * buswidths will have larger limits.