Re: [PATCH v3 2/7] mmc: sdhci-of-arasan: Fix SDHCI_RESET_ALL for CQHCI

Adrian Hunter
2022-10-25T13:09:52Z

On 24/10/22 20:54, Brian Norris wrote:
> SDHCI_RESET_ALL resets will reset the hardware CQE state, but we aren't
> tracking that properly in software. When out of sync, we may trigger
> various timeouts.
>
> It's not typical to perform resets while CQE is enabled, but one
> particular case I hit commonly enough: mmc_suspend() -> mmc_power_off().
> Typically we will eventually deactivate CQE (cqhci_suspend() ->
> cqhci_deactivate()), but that's not guaranteed -- in particular, if
> we perform a partial (e.g., interrupted) system suspend.
>
> The same bug was already found and fixed for two other drivers, in v5.7
> and v5.9:
>
> 5cf583f1fb9c mmc: sdhci-msm: Deactivate CQE during SDHC reset

As checkpatch.pl says:

ERROR: Please use git commit description style 'commit <12+ chars of sha1> (" ")' - ie: 'commit 5cf583f1fb9c ("mmc: sdhci-msm: Deactivate CQE during SDHC reset")'

> df57d73276b8 mmc: sdhci-pci: Fix SDHCI_RESET_ALL for CQHCI for Intel GLK-based controllers

And again

>
> The latter is especially prescient, saying "other drivers using CQHCI
> might benefit from a similar change, if they also have CQHCI reset by
> SDHCI_RESET_ALL."
>
> So like these other patches, deactivate CQHCI when resetting the
> controller. Do this via the new sdhci_and_cqhci_reset() helper.

For stable, this patch is dependent on "mmc: cqhci: Provide
helper for resetting both SDHCI and CQHCI". Best point that out
here in this commit message as well.

>
> Fixes: 84362d79f436 ("mmc: sdhci-of-arasan: Add CQHCI support for arasan,sdhci-5.1")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Brian Norris <briannorris@chromium.org>
> Reviewed-by: Guenter Roeck <linux@roeck-us.net>

Otherwise:

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
>
> Changes in v3:
> - Refactor to a "SDHCI and CQHCI" helper -- sdhci_and_cqhci_reset()
>
> Changes in v2:
> - Rely on cqhci_deactivate() to safely handle (ignore)
> not-yet-initialized CQE support
>
> drivers/mmc/host/sdhci-of-arasan.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> index 3997cad1f793..cfb891430174 100644
> --- a/drivers/mmc/host/sdhci-of-arasan.c
> +++ b/drivers/mmc/host/sdhci-of-arasan.c
> @@ -25,6 +25,7 @@
> #include <linux/firmware/xlnx-zynqmp.h>
>
> #include "cqhci.h"
> +#include "sdhci-cqhci.h"
> #include "sdhci-pltfm.h"
>
> #define SDHCI_ARASAN_VENDOR_REGISTER 0x78
> @@ -366,7 +367,7 @@ static void sdhci_arasan_reset(struct sdhci_host *host, u8 mask)
> struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
>
> - sdhci_reset(host, mask);
> + sdhci_and_cqhci_reset(host, mask);
>
> if (sdhci_arasan->quirks & SDHCI_ARASAN_QUIRK_FORCE_CDTEST) {
> ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);