2022-10-19 22:04:44

by Brian Norris

[permalink] [raw]
Subject: [PATCH v2 4/7] mms: sdhci-esdhc-imx: Fix SDHCI_RESET_ALL for CQHCI

[[ NOTE: this is completely untested by the author, but included solely
because, as noted in commit df57d73276b8 ("mmc: sdhci-pci: Fix
SDHCI_RESET_ALL for CQHCI for Intel GLK-based controllers"), "other
drivers using CQHCI might benefit from a similar change, if they
also have CQHCI reset by SDHCI_RESET_ALL." We've now seen the same
bug on at least MSM, Arasan, and Intel hardware. ]]

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 this may
occur in some suspend or error recovery scenarios.

Fixes: bb6e358169bf ("mmc: sdhci-esdhc-imx: add CMDQ support")
Signed-off-by: Brian Norris <[email protected]>
---

Changes in v2:
- Drop unnecessary ESDHC_FLAG_CQHCI check

drivers/mmc/host/sdhci-esdhc-imx.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 55981b0f0b10..c07df7b71b22 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -1288,6 +1288,9 @@ static void esdhc_set_uhs_signaling(struct sdhci_host *host, unsigned timing)

static void esdhc_reset(struct sdhci_host *host, u8 mask)
{
+ if ((host->mmc->caps2 & MMC_CAP2_CQE) && (mask & SDHCI_RESET_ALL))
+ cqhci_deactivate(host->mmc);
+
sdhci_reset(host, mask);

sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
--
2.38.0.413.g74048e4d9e-goog


2022-10-21 02:42:34

by Bough Chen

[permalink] [raw]
Subject: RE: [PATCH v2 4/7] mms: sdhci-esdhc-imx: Fix SDHCI_RESET_ALL for CQHCI

> -----Original Message-----
> From: Brian Norris <[email protected]>
> Sent: 2022??10??20?? 5:55
> To: Ulf Hansson <[email protected]>
> Cc: Shawn Lin <[email protected]>; Shawn Guo
> <[email protected]>; Fabio Estevam <[email protected]>; Bough Chen
> <[email protected]>; Broadcom internal kernel review list
> <[email protected]>; dl-linux-imx <[email protected]>;
> Pengutronix Kernel Team <[email protected]>; Florian Fainelli
> <[email protected]>; Michal Simek <[email protected]>; Faiz Abbas
> <[email protected]>; [email protected]; Jonathan Hunter
> <[email protected]>; Al Cooper <[email protected]>;
> [email protected]; Sowjanya Komatineni
> <[email protected]>; [email protected]; Thierry Reding
> <[email protected]>; Adrian Hunter <[email protected]>;
> Sascha Hauer <[email protected]>; Brian Norris
> <[email protected]>
> Subject: [PATCH v2 4/7] mms: sdhci-esdhc-imx: Fix SDHCI_RESET_ALL for CQHCI
>
> [[ NOTE: this is completely untested by the author, but included solely
> because, as noted in commit df57d73276b8 ("mmc: sdhci-pci: Fix
> SDHCI_RESET_ALL for CQHCI for Intel GLK-based controllers"), "other
> drivers using CQHCI might benefit from a similar change, if they
> also have CQHCI reset by SDHCI_RESET_ALL." We've now seen the same
> bug on at least MSM, Arasan, and Intel hardware. ]]
>
> 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 this may occur in
> some suspend or error recovery scenarios.
>
> Fixes: bb6e358169bf ("mmc: sdhci-esdhc-imx: add CMDQ support")
> Signed-off-by: Brian Norris <[email protected]>

Reviewed-by: Haibo Chen <[email protected]>

> ---
>
> Changes in v2:
> - Drop unnecessary ESDHC_FLAG_CQHCI check
>
> drivers/mmc/host/sdhci-esdhc-imx.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c
> b/drivers/mmc/host/sdhci-esdhc-imx.c
> index 55981b0f0b10..c07df7b71b22 100644
> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> @@ -1288,6 +1288,9 @@ static void esdhc_set_uhs_signaling(struct sdhci_host
> *host, unsigned timing)
>
> static void esdhc_reset(struct sdhci_host *host, u8 mask) {
> + if ((host->mmc->caps2 & MMC_CAP2_CQE) && (mask &
> SDHCI_RESET_ALL))
> + cqhci_deactivate(host->mmc);
> +
> sdhci_reset(host, mask);
>
> sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
> --
> 2.38.0.413.g74048e4d9e-goog