[PATCH v4 2/7] mmc: sdhci-of-arasan: Fix SDHCI_RESET_ALL for CQHCI

From: Brian Norris
Date: Wed Oct 26 2022 - 15:43:31 EST


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")
df57d73276b8 ("mmc: sdhci-pci: Fix SDHCI_RESET_ALL for CQHCI for Intel
GLK-based controllers")

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.

This patch depends on (and should not compile without) the patch
entitled "mmc: cqhci: Provide helper for resetting both SDHCI and
CQHCI".

Fixes: 84362d79f436 ("mmc: sdhci-of-arasan: Add CQHCI support for arasan,sdhci-5.1")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---

Changes in v4:
- Improve for-stable cherry-picking notes
- Add Adrian's Ack

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);
--
2.38.0.135.g90850a2211-goog