| Message ID | 20190716082655.1620-1-peter.ujfalusi@ti.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | dmaengine: ti: edma: Polled completion support | expand |
On 16-07-19, 11:26, Peter Ujfalusi wrote: > Hi, > > Changes since v4: > - Split the DMA_COMPLETE and !txstate check as Vinod suggested > > Change since v3: > - fix DMA pointer tracking for memcpy > - completion polling is only done when it is asked by not providing > DMA_PREP_INTERRUPT for memcpy > > Changes since v2: > - Fix typo in the comment for patch 0 > > Changes since v1: > - Cleanup patch for the array register handling > - typo fixed in patch2 commit message > > The code around the array register access was pretty confusing for the first > look, so clean them up first then use the cleaner way in the polled handling. > > When a DMA client driver does not set the DMA_PREP_INTERRUPT because it > does not want to use interrupts for DMA completion or because it can not > rely on DMA interrupts due to executing the memcpy when interrupts are > disabled it will poll the status of the transfer. > > Since we can not tell from any EDMA register that the transfer is > completed, we can only know that the paRAM set has been sent to TPTC for > processing we need to check the residue of the transfer, if it is 0 then > the transfer is completed. > > The polled completion can bve tested by applying: > https://patchwork.kernel.org/patch/10966499/ > > Enabling the memcpy for EDMA and run the dmatest with polled = 1. > > Or, enable the EDMA memcpy support and boot up any dra7 family device with > display enabled. The workaround for DMM errata i878 uses polled DMA memcpy. Applied, thanks. Fixed typo in 2nd patch while at it
Vinod, On 29/07/2019 9.42, Vinod Koul wrote: > On 16-07-19, 11:26, Peter Ujfalusi wrote: >> Hi, >> >> Changes since v4: >> - Split the DMA_COMPLETE and !txstate check as Vinod suggested >> >> Change since v3: >> - fix DMA pointer tracking for memcpy >> - completion polling is only done when it is asked by not providing >> DMA_PREP_INTERRUPT for memcpy >> >> Changes since v2: >> - Fix typo in the comment for patch 0 >> >> Changes since v1: >> - Cleanup patch for the array register handling >> - typo fixed in patch2 commit message >> >> The code around the array register access was pretty confusing for the first >> look, so clean them up first then use the cleaner way in the polled handling. >> >> When a DMA client driver does not set the DMA_PREP_INTERRUPT because it >> does not want to use interrupts for DMA completion or because it can not >> rely on DMA interrupts due to executing the memcpy when interrupts are >> disabled it will poll the status of the transfer. >> >> Since we can not tell from any EDMA register that the transfer is >> completed, we can only know that the paRAM set has been sent to TPTC for >> processing we need to check the residue of the transfer, if it is 0 then >> the transfer is completed. >> >> The polled completion can bve tested by applying: >> https://patchwork.kernel.org/patch/10966499/ >> >> Enabling the memcpy for EDMA and run the dmatest with polled = 1. >> >> Or, enable the EDMA memcpy support and boot up any dra7 family device with >> display enabled. The workaround for DMM errata i878 uses polled DMA memcpy. > > Applied, thanks. Fixed typo in 2nd patch while at it Thank you! I was about to send v6 with the fixed typo. - Péter Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
Vinod, On 29/07/2019 9.42, Vinod Koul wrote: > On 16-07-19, 11:26, Peter Ujfalusi wrote: >> Hi, >> >> Changes since v4: >> - Split the DMA_COMPLETE and !txstate check as Vinod suggested >> >> Change since v3: >> - fix DMA pointer tracking for memcpy >> - completion polling is only done when it is asked by not providing >> DMA_PREP_INTERRUPT for memcpy >> >> Changes since v2: >> - Fix typo in the comment for patch 0 >> >> Changes since v1: >> - Cleanup patch for the array register handling >> - typo fixed in patch2 commit message >> >> The code around the array register access was pretty confusing for the first >> look, so clean them up first then use the cleaner way in the polled handling. >> >> When a DMA client driver does not set the DMA_PREP_INTERRUPT because it >> does not want to use interrupts for DMA completion or because it can not >> rely on DMA interrupts due to executing the memcpy when interrupts are >> disabled it will poll the status of the transfer. >> >> Since we can not tell from any EDMA register that the transfer is >> completed, we can only know that the paRAM set has been sent to TPTC for >> processing we need to check the residue of the transfer, if it is 0 then >> the transfer is completed. >> >> The polled completion can bve tested by applying: >> https://patchwork.kernel.org/patch/10966499/ Should I resend this patch so the polled mode can be tested in upstream? - Péter Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
On 29-07-19, 10:24, Peter Ujfalusi wrote: > Vinod, > > On 29/07/2019 9.42, Vinod Koul wrote: > > On 16-07-19, 11:26, Peter Ujfalusi wrote: > >> Hi, > >> > >> Changes since v4: > >> - Split the DMA_COMPLETE and !txstate check as Vinod suggested > >> > >> Change since v3: > >> - fix DMA pointer tracking for memcpy > >> - completion polling is only done when it is asked by not providing > >> DMA_PREP_INTERRUPT for memcpy > >> > >> Changes since v2: > >> - Fix typo in the comment for patch 0 > >> > >> Changes since v1: > >> - Cleanup patch for the array register handling > >> - typo fixed in patch2 commit message > >> > >> The code around the array register access was pretty confusing for the first > >> look, so clean them up first then use the cleaner way in the polled handling. > >> > >> When a DMA client driver does not set the DMA_PREP_INTERRUPT because it > >> does not want to use interrupts for DMA completion or because it can not > >> rely on DMA interrupts due to executing the memcpy when interrupts are > >> disabled it will poll the status of the transfer. > >> > >> Since we can not tell from any EDMA register that the transfer is > >> completed, we can only know that the paRAM set has been sent to TPTC for > >> processing we need to check the residue of the transfer, if it is 0 then > >> the transfer is completed. > >> > >> The polled completion can bve tested by applying: > >> https://patchwork.kernel.org/patch/10966499/ > > Should I resend this patch so the polled mode can be tested in upstream? Yes sure
On 29-07-19, 10:22, Peter Ujfalusi wrote: > Vinod, > > On 29/07/2019 9.42, Vinod Koul wrote: > > On 16-07-19, 11:26, Peter Ujfalusi wrote: > >> Hi, > >> > >> Changes since v4: > >> - Split the DMA_COMPLETE and !txstate check as Vinod suggested > >> > >> Change since v3: > >> - fix DMA pointer tracking for memcpy > >> - completion polling is only done when it is asked by not providing > >> DMA_PREP_INTERRUPT for memcpy > >> > >> Changes since v2: > >> - Fix typo in the comment for patch 0 > >> > >> Changes since v1: > >> - Cleanup patch for the array register handling > >> - typo fixed in patch2 commit message > >> > >> The code around the array register access was pretty confusing for the first > >> look, so clean them up first then use the cleaner way in the polled handling. > >> > >> When a DMA client driver does not set the DMA_PREP_INTERRUPT because it > >> does not want to use interrupts for DMA completion or because it can not > >> rely on DMA interrupts due to executing the memcpy when interrupts are > >> disabled it will poll the status of the transfer. > >> > >> Since we can not tell from any EDMA register that the transfer is > >> completed, we can only know that the paRAM set has been sent to TPTC for > >> processing we need to check the residue of the transfer, if it is 0 then > >> the transfer is completed. > >> > >> The polled completion can bve tested by applying: > >> https://patchwork.kernel.org/patch/10966499/ > >> > >> Enabling the memcpy for EDMA and run the dmatest with polled = 1. > >> > >> Or, enable the EDMA memcpy support and boot up any dra7 family device with > >> display enabled. The workaround for DMM errata i878 uses polled DMA memcpy. > > > > Applied, thanks. Fixed typo in 2nd patch while at it > > Thank you! I was about to send v6 with the fixed typo. Simpler typos are ok to fix while applying