On 15/07/19 2:37 PM, Baolin Wang wrote: > Hi Adrian, > > On Mon, 15 Jul 2019 at 19:20, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote: >> >> On 15/07/19 1:58 PM, Baolin Wang wrote: >>> In sdhci_runtime_resume_host() function, we will always do software reset >>> for all, but according to the specification, we should issue reset command >>> and reinitialize the SD/eMMC card. >> >> Where does it say that? > > I checked the SD host controller simplified specification Ver4.20, and > in Page 75, Software Reset For All bit, it says "if this bit is set > to1, the host driver should issue reset command and reinitialize the > SD card". (I did not check other versions). That might simply be assuming that the bus power also controls the card power. > >> >>> However, we only do reinitialize the >>> SD/eMMC card when the SD/eMMC card are power down during runtime suspend. >>> >>> Thus for those platforms that do not power down the SD/eMMC card during >>> runtime suspend, we should not do software reset for all. >>> To fix this >>> issue, we can add one condition to validate the MMC_CAP_AGGRESSIVE_PM >>> to decide if we can do software reset for all or just reset command >>> and data lines. >>> >>> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx> >>> --- >>> drivers/mmc/host/sdhci.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c >>> index 9715834..470c5e0 100644 >>> --- a/drivers/mmc/host/sdhci.c >>> +++ b/drivers/mmc/host/sdhci.c >>> @@ -3333,7 +3333,7 @@ int sdhci_runtime_resume_host(struct sdhci_host *host) >>> host->ops->enable_dma(host); >>> } >>> >>> - sdhci_init(host, 0); >>> + sdhci_init(host, !(mmc->caps & MMC_CAP_AGGRESSIVE_PM)); >> >> We have done a full reset for a long time, so it would be surprising to need >> to change it. >> >> What problem is it causing? > > If we did not power down the SD card during runtime suspend, and we > reset for all when runtime resume, our SD host controller can not work > well, will meet some strange behavior, like: > > [ 6.525397] mmc0: Got data interrupt 0x00000002 even though no data > operation was in progress. > [ 6.534189] mmc0: sdhci: ============ SDHCI REGISTER DUMP =========== > [ 6.540797] mmc0: sdhci: Sys addr: 0x00000008 | Version: 0x00000004 > [ 6.547413] mmc0: sdhci: Blk size: 0x00000200 | Blk cnt: 0x00000000 > [ 6.554029] mmc0: sdhci: Argument: 0x03200101 | Trn mode: 0x00000033 > [ 6.560645] mmc0: sdhci: Present: 0x01f000f0 | Host ctl: 0x00000030 > [ 6.567262] mmc0: sdhci: Power: 0x00000000 | Blk gap: 0x00000000 > [ 6.573877] mmc0: sdhci: Wake-up: 0x00000000 | Clock: 0x00000007 > [ 6.580493] mmc0: sdhci: Timeout: 0x0000000e | Int stat: 0x00000000 > [ 6.587109] mmc0: sdhci: Int enab: 0x037f000b | Sig enab: 0x037f000b > [ 6.593726] mmc0: sdhci: ACmd stat: 0x00000000 | Slot int: 0x00000000 > [ 6.600342] mmc0: sdhci: Caps: 0x1c6d0080 | Caps_1: 0x08000007 > [ 6.606959] mmc0: sdhci: Cmd: 0x0000061b | Max curr: 0x00ffffff > [ 6.613574] mmc0: sdhci: Resp[0]: 0x00001201 | Resp[1]: 0x00000000 > [ 6.620190] mmc0: sdhci: Resp[2]: 0x00000000 | Resp[3]: 0x00000000 > [ 6.626806] mmc0: sdhci: Host ctl2: 0x00003807 > [ 6.631364] mmc0: sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x00000000df062000 > [ 6.638697] mmc0: sdhci: ============================================ > [ 6.645379] mmc0: cache flush error -84 > > Got data interrupt but no data commands are processing now. With this > patch, then our SD host controller can work well. Did I miss anything > else? Thanks. The response seems to show the card in state 9 bus-testing, which would suggest the use of CMD19 for eMMC. Perhaps the wrong command is used for eMMC re-tuning? The difficulty with changing long standing flow is that it might reveal problems for other existing hardware. Did you consider making a driver-specific change? The ->reset() callback could be used.
