| Message ID | 20190217121513.22965-2-beagleboard@davidjohnsummers.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ARM: dts: rk3288 Tinker Board (S) updates | expand |
Hi David, On 2019-02-17 12:15 pm, David Summers wrote: > This patch makes some minor changes to how the sd card is > described in the device tree for the ASUS Tinker Board (S). In > particular on the Tinker Board S, when booted from the eMMC, and with > no card in the sd slot, and the log has endless messages about not > being able to detect the card. > > Several methods to remove this error have been tried, the only one > that works is the broken-cd and so that is what is applied here. I don't have a Tinker Board, but the symptom sounds instantly familiar from hacking on another RK3288 box; have you tried adding "regulator-always-on" to the vccio_sd regulator? With the reference design (which I would assume the Tinker Board has no reason to deviate from in this area), the CD pin is either wired directly to the SoC with no external pull-up, or explicitly pulled up to VCCIO_SD. Either way, when the dwmmc driver probes and discovers there is no card present, it sets the currently-unnecessary vqmmc-supply as inactive, and thus the regulator core turns off VCCIO_SD entirely. Unfortunately, this removes the voltage from the entire I/O domain including the internal pull-up, which ends up leaving the CD pin floating and generating spurious events. Robin. > Alas the ASUS schematic is not clear enough to indicate if the card > detect is wired up to the cpu, the schematic does not show internal > wiring on the Tinker Board! > > Now this error didn't show up on the Tinker Board, as that machine > only boots where there is a sd card installed. However as the TB and > TBS are so similar it is expected that the Tinker Board also doesn't > have a functioning card detect. Hence the change here is made to the > dtsi file, so it applies to both TB and TBS. > > The disable-wp is also removed, it doesnt seem needed on the micro > sdcard slots, and without thisn the card can still be written > to. Hence this flag is also removed. > > Signed-off-by: David Summers <beagleboard@davidjohnsummers.uk> > --- > arch/arm/boot/dts/rk3288-tinker.dtsi | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/arch/arm/boot/dts/rk3288-tinker.dtsi b/arch/arm/boot/dts/rk3288-tinker.dtsi > index 2b38075a2917..fceaeed44e34 100644 > --- a/arch/arm/boot/dts/rk3288-tinker.dtsi > +++ b/arch/arm/boot/dts/rk3288-tinker.dtsi > @@ -432,9 +432,7 @@ > bus-width = <4>; > cap-mmc-highspeed; > cap-sd-highspeed; > - card-detect-delay = <200>; > - disable-wp; /* wp not hooked up */ > + broken-cd; > pinctrl-names = "default"; > pinctrl-0 = <&sdmmc_clk &sdmmc_cmd &sdmmc_cd &sdmmc_bus4>; > status = "okay"; >
On 17/02/2019 14:00, Robin Murphy wrote: > Hi David, > > On 2019-02-17 12:15 pm, David Summers wrote: >> This patch makes some minor changes to how the sd card is >> described in the device tree for the ASUS Tinker Board (S). In >> particular on the Tinker Board S, when booted from the eMMC, and with >> no card in the sd slot, and the log has endless messages about not >> being able to detect the card. >> >> Several methods to remove this error have been tried, the only one >> that works is the broken-cd and so that is what is applied here. > > I don't have a Tinker Board, but the symptom sounds instantly familiar > from hacking on another RK3288 box; have you tried adding > "regulator-always-on" to the vccio_sd regulator? > > With the reference design (which I would assume the Tinker Board has > no reason to deviate from in this area), the CD pin is either wired > directly to the SoC with no external pull-up, or explicitly pulled up > to VCCIO_SD. Either way, when the dwmmc driver probes and discovers > there is no card present, it sets the currently-unnecessary > vqmmc-supply as inactive, and thus the regulator core turns off > VCCIO_SD entirely. Unfortunately, this removes the voltage from the > entire I/O domain including the internal pull-up, which ends up > leaving the CD pin floating and generating spurious events. > > Robin. Hi Robin, An interesting suggestion - no it hasn't been tried to always set the vccio_sd regulator on. Will give it a go on ArchLinux Arm. I guess this would explain why the Tinker Board booting from sd doesn't see the error, as its enabled probably in uboot and then keeps working. IIRC though, if booting the TBS from eMMC, then inserting an sd card and the errors stop. I guess this wouldn't happen if the power wasn't applied? I guess also that "regulator-always-on" is a quick test - but that for submission to kernel it would be better done via "mmc-pwrseq-simple"? Anyway I set up a test - so we can confirm this. David.
Hi David, we need a better patch subject here e.g. ARM: dts: rk3288-tinker: Fix SD card detection plus a Fixes tag for the commit we want to fix. > David Summers <beagleboard@davidjohnsummers.uk> hat am 17. Februar 2019 um 13:15 geschrieben: > > > This patch makes some minor changes to how the sd card is > described in the device tree for the ASUS Tinker Board (S). In > particular on the Tinker Board S, when booted from the eMMC, and with > no card in the sd slot, and the log has endless messages about not > being able to detect the card. > > Several methods to remove this error have been tried, the only one > that works is the broken-cd and so that is what is applied here. > > Alas the ASUS schematic is not clear enough to indicate if the card > detect is wired up to the cpu, the schematic does not show internal > wiring on the Tinker Board! > > Now this error didn't show up on the Tinker Board, as that machine > only boots where there is a sd card installed. However as the TB and > TBS are so similar it is expected that the Tinker Board also doesn't > have a functioning card detect. Hence the change here is made to the > dtsi file, so it applies to both TB and TBS. > > The disable-wp is also removed, it doesnt seem needed on the micro > sdcard slots, and without thisn the card can still be written > to. Hence this flag is also removed. > > Signed-off-by: David Summers <beagleboard@davidjohnsummers.uk> > --- > arch/arm/boot/dts/rk3288-tinker.dtsi | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/arch/arm/boot/dts/rk3288-tinker.dtsi b/arch/arm/boot/dts/rk3288-tinker.dtsi > index 2b38075a2917..fceaeed44e34 100644 > --- a/arch/arm/boot/dts/rk3288-tinker.dtsi > +++ b/arch/arm/boot/dts/rk3288-tinker.dtsi > @@ -432,9 +432,7 @@ > bus-width = <4>; > cap-mmc-highspeed; > cap-sd-highspeed; > - card-detect-delay = <200>; > - disable-wp; /* wp not hooked up */ I think we should keep as long as it doesn't hurt. > + broken-cd; > pinctrl-names = "default"; > pinctrl-0 = <&sdmmc_clk &sdmmc_cmd &sdmmc_cd &sdmmc_bus4>; > status = "okay"; > -- > beagleboard@davidjohnsummers.uk > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On 17/02/2019 15:19, David Summers wrote: > On 17/02/2019 14:00, Robin Murphy wrote: >> Hi David, >> >> On 2019-02-17 12:15 pm, David Summers wrote: >>> This patch makes some minor changes to how the sd card is >>> described in the device tree for the ASUS Tinker Board (S). In >>> particular on the Tinker Board S, when booted from the eMMC, and with >>> no card in the sd slot, and the log has endless messages about not >>> being able to detect the card. >>> >>> Several methods to remove this error have been tried, the only one >>> that works is the broken-cd and so that is what is applied here. >> >> I don't have a Tinker Board, but the symptom sounds instantly familiar >> from hacking on another RK3288 box; have you tried adding >> "regulator-always-on" to the vccio_sd regulator? >> >> With the reference design (which I would assume the Tinker Board has >> no reason to deviate from in this area), the CD pin is either wired >> directly to the SoC with no external pull-up, or explicitly pulled up >> to VCCIO_SD. Either way, when the dwmmc driver probes and discovers >> there is no card present, it sets the currently-unnecessary >> vqmmc-supply as inactive, and thus the regulator core turns off >> VCCIO_SD entirely. Unfortunately, this removes the voltage from the >> entire I/O domain including the internal pull-up, which ends up >> leaving the CD pin floating and generating spurious events. >> >> Robin. > > Hi Robin, > > An interesting suggestion - no it hasn't been tried to always set the > vccio_sd regulator on. Will give it a go on ArchLinux Arm. > > I guess this would explain why the Tinker Board booting from sd doesn't > see the error, as its enabled probably in uboot and then keeps working. > > IIRC though, if booting the TBS from eMMC, then inserting an sd card and > the errors stop. I guess this wouldn't happen if the power wasn't applied? That's the fun part of this scenario - the presence of a card is unambiguous, it's only the absence of one which depends on the pull-up state, so whenever as a card is inserted everything does work correctly. Assuming they are the same errors I was seeing, they're from the driver *thinking* a card is inserted due to CD floating low, then failing to communicate with it, after which it powers down the I/O interface again and the whole cycle begins anew. > I guess also that "regulator-always-on" is a quick test - but that for > submission to kernel it would be better done via "mmc-pwrseq-simple"? No, it's a valid description of the hardware to say "disabling this regulator makes something fail to work as expected" if that is truly the case. Besides, pwrseq is about how to initialise a detected present card, not how to correctly detect that presence in the first place. > Anyway I set up a test - so we can confirm this. Great - there is of course still the possibility that the pin really isn't wired up at all, in which case ignoring CD and taking the CPU overhead of polling would be the only option, but the vendor DT doesn't have any signs to suggest that's the case, and makes me lean more towards the pull-up issue. Robin.
Thanks Stefan, If the change to make sure that power is set to vccio_sd work, and so I have to do another patch, I'll make sure I update. David. On 17/02/2019 20:29, Stefan Wahren wrote: > Hi David, > > we need a better patch subject here e.g. > > ARM: dts: rk3288-tinker: Fix SD card detection > > plus a Fixes tag for the commit we want to fix. > >> David Summers <beagleboard@davidjohnsummers.uk> hat am 17. Februar 2019 um 13:15 geschrieben: >> >> >> This patch makes some minor changes to how the sd card is >> described in the device tree for the ASUS Tinker Board (S). In >> particular on the Tinker Board S, when booted from the eMMC, and with >> no card in the sd slot, and the log has endless messages about not >> being able to detect the card. >> >> Several methods to remove this error have been tried, the only one >> that works is the broken-cd and so that is what is applied here. >> >> Alas the ASUS schematic is not clear enough to indicate if the card >> detect is wired up to the cpu, the schematic does not show internal >> wiring on the Tinker Board! >> >> Now this error didn't show up on the Tinker Board, as that machine >> only boots where there is a sd card installed. However as the TB and >> TBS are so similar it is expected that the Tinker Board also doesn't >> have a functioning card detect. Hence the change here is made to the >> dtsi file, so it applies to both TB and TBS. >> >> The disable-wp is also removed, it doesnt seem needed on the micro >> sdcard slots, and without thisn the card can still be written >> to. Hence this flag is also removed. >> >> Signed-off-by: David Summers <beagleboard@davidjohnsummers.uk> >> --- >> arch/arm/boot/dts/rk3288-tinker.dtsi | 3 +-- >> 1 file changed, 1 insertion(+), 2 deletions(-) >> >> diff --git a/arch/arm/boot/dts/rk3288-tinker.dtsi b/arch/arm/boot/dts/rk3288-tinker.dtsi >> index 2b38075a2917..fceaeed44e34 100644 >> --- a/arch/arm/boot/dts/rk3288-tinker.dtsi >> +++ b/arch/arm/boot/dts/rk3288-tinker.dtsi >> @@ -432,9 +432,7 @@ >> bus-width = <4>; >> cap-mmc-highspeed; >> cap-sd-highspeed; >> - card-detect-delay = <200>; >> - disable-wp; /* wp not hooked up */ > I think we should keep as long as it doesn't hurt. > >> + broken-cd; >> pinctrl-names = "default"; >> pinctrl-0 = <&sdmmc_clk &sdmmc_cmd &sdmmc_cd &sdmmc_bus4>; >> status = "okay"; >> -- >> beagleboard@davidjohnsummers.uk >> >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-kernel@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On 18/02/2019 11:54, Robin Murphy wrote: > On 17/02/2019 15:19, David Summers wrote: >> On 17/02/2019 14:00, Robin Murphy wrote: >>> Hi David, >>> >>> On 2019-02-17 12:15 pm, David Summers wrote: >>>> This patch makes some minor changes to how the sd card is >>>> described in the device tree for the ASUS Tinker Board (S). In >>>> particular on the Tinker Board S, when booted from the eMMC, and with >>>> no card in the sd slot, and the log has endless messages about not >>>> being able to detect the card. >>>> >>>> Several methods to remove this error have been tried, the only one >>>> that works is the broken-cd and so that is what is applied here. >>> >>> I don't have a Tinker Board, but the symptom sounds instantly >>> familiar from hacking on another RK3288 box; have you tried adding >>> "regulator-always-on" to the vccio_sd regulator? >>> >>> With the reference design (which I would assume the Tinker Board has >>> no reason to deviate from in this area), the CD pin is either wired >>> directly to the SoC with no external pull-up, or explicitly pulled >>> up to VCCIO_SD. Either way, when the dwmmc driver probes and >>> discovers there is no card present, it sets the >>> currently-unnecessary vqmmc-supply as inactive, and thus the >>> regulator core turns off VCCIO_SD entirely. Unfortunately, this >>> removes the voltage from the entire I/O domain including the >>> internal pull-up, which ends up leaving the CD pin floating and >>> generating spurious events. >>> >>> Robin. >> >> Hi Robin, >> >> An interesting suggestion - no it hasn't been tried to always set the >> vccio_sd regulator on. Will give it a go on ArchLinux Arm. >> >> I guess this would explain why the Tinker Board booting from sd >> doesn't see the error, as its enabled probably in uboot and then >> keeps working. >> >> IIRC though, if booting the TBS from eMMC, then inserting an sd card >> and the errors stop. I guess this wouldn't happen if the power wasn't >> applied? > > That's the fun part of this scenario - the presence of a card is > unambiguous, it's only the absence of one which depends on the pull-up > state, so whenever as a card is inserted everything does work > correctly. Assuming they are the same errors I was seeing, they're > from the driver *thinking* a card is inserted due to CD floating low, > then failing to communicate with it, after which it powers down the > I/O interface again and the whole cycle begins anew. > >> I guess also that "regulator-always-on" is a quick test - but that >> for submission to kernel it would be better done via >> "mmc-pwrseq-simple"? > > No, it's a valid description of the hardware to say "disabling this > regulator makes something fail to work as expected" if that is truly > the case. Besides, pwrseq is about how to initialise a detected > present card, not how to correctly detect that presence in the first > place. > >> Anyway I set up a test - so we can confirm this. > > Great - there is of course still the possibility that the pin really > isn't wired up at all, in which case ignoring CD and taking the CPU > overhead of polling would be the only option, but the vendor DT > doesn't have any signs to suggest that's the case, and makes me lean > more towards the pull-up issue. > > Robin. Robin, Heard back from the user on ArchLinux Arm who has a tinker Board S, he tested your solution, and it worked. Excellent, as it means the CPU won't have to poll the card! I'll probably add both "regulator-always-on;" and "regulator-boot-on;", as reading the regulator documentation, and the Tinker Board boots from sd card, and the TinkerBoard S has the option of booting from the sd card - we can be fairly sure that uboot has already enabled the power supply. So best to withdraw this patch. I'll do a fresh one, when I get time - probably the weekend ... Thanks for the help, I should have though of looking beyond sdmmc part of device tree. So we are grateful that you remembered your solution when you had the problem on another board. Regards, David
diff --git a/arch/arm/boot/dts/rk3288-tinker.dtsi b/arch/arm/boot/dts/rk3288-tinker.dtsi index 2b38075a2917..fceaeed44e34 100644 --- a/arch/arm/boot/dts/rk3288-tinker.dtsi +++ b/arch/arm/boot/dts/rk3288-tinker.dtsi @@ -432,9 +432,7 @@ bus-width = <4>; cap-mmc-highspeed; cap-sd-highspeed; - card-detect-delay = <200>; - disable-wp; /* wp not hooked up */ + broken-cd; pinctrl-names = "default"; pinctrl-0 = <&sdmmc_clk &sdmmc_cmd &sdmmc_cd &sdmmc_bus4>; status = "okay"; --
This patch makes some minor changes to how the sd card is described in the device tree for the ASUS Tinker Board (S). In particular on the Tinker Board S, when booted from the eMMC, and with no card in the sd slot, and the log has endless messages about not being able to detect the card. Several methods to remove this error have been tried, the only one that works is the broken-cd and so that is what is applied here. Alas the ASUS schematic is not clear enough to indicate if the card detect is wired up to the cpu, the schematic does not show internal wiring on the Tinker Board! Now this error didn't show up on the Tinker Board, as that machine only boots where there is a sd card installed. However as the TB and TBS are so similar it is expected that the Tinker Board also doesn't have a functioning card detect. Hence the change here is made to the dtsi file, so it applies to both TB and TBS. The disable-wp is also removed, it doesnt seem needed on the micro sdcard slots, and without thisn the card can still be written to. Hence this flag is also removed. Signed-off-by: David Summers <beagleboard@davidjohnsummers.uk> --- arch/arm/boot/dts/rk3288-tinker.dtsi | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) beagleboard@davidjohnsummers.uk