From 21e35e898aa9ef7781632959db8613a5380f2eae Mon Sep 17 00:00:00 2001
From: Pradeep P V K <pragalla@codeaurora.org>
Date: Wed, 3 Mar 2021 14:02:11 +0530
Subject: [PATCH] mmc: sdhci: Check for reset prior to DMA address unmap
Git-commit: 21e35e898aa9ef7781632959db8613a5380f2eae
Patch-mainline: v5.13-rc1
References: git-fixes
For data read commands, SDHC may initiate data transfers even before it
completely process the command response. In case command itself fails,
driver un-maps the memory associated with data transfer but this memory
can still be accessed by SDHC for the already initiated data transfer.
This scenario can lead to un-mapped memory access error.
To avoid this scenario, reset SDHC (when command fails) prior to
un-mapping memory. Resetting SDHC ensures that all in-flight data
transfers are either aborted or completed. So we don't run into this
scenario.
Swap the reset, un-map steps sequence in sdhci_request_done().
Suggested-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
Signed-off-by: Pradeep P V K <pragalla@codeaurora.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/1614760331-43499-1-git-send-email-pragalla@qti.qualcomm.com
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/mmc/host/sdhci.c | 60 +++++++++++++++++++++-------------------
1 file changed, 31 insertions(+), 29 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 2d73407ee52e..a9e20818ff3a 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2996,6 +2996,37 @@ static bool sdhci_request_done(struct sdhci_host *host)
return true;
}
+ /*
+ * The controller needs a reset of internal state machines
+ * upon error conditions.
+ */
+ if (sdhci_needs_reset(host, mrq)) {
+ /*
+ * Do not finish until command and data lines are available for
+ * reset. Note there can only be one other mrq, so it cannot
+ * also be in mrqs_done, otherwise host->cmd and host->data_cmd
+ * would both be null.
+ */
+ if (host->cmd || host->data_cmd) {
+ spin_unlock_irqrestore(&host->lock, flags);
+ return true;
+ }
+
+ /* Some controllers need this kick or reset won't work here */
+ if (host->quirks & SDHCI_QUIRK_CLOCK_BEFORE_RESET)
+ /* This is to force an update */
+ host->ops->set_clock(host, host->clock);
+
+ /*
+ * Spec says we should do both at the same time, but Ricoh
+ * controllers do not like that.
+ */
+ sdhci_do_reset(host, SDHCI_RESET_CMD);
+ sdhci_do_reset(host, SDHCI_RESET_DATA);
+
+ host->pending_reset = false;
+ }
+
/*
* Always unmap the data buffers if they were mapped by
* sdhci_prepare_data() whenever we finish with a request.
@@ -3059,35 +3090,6 @@ static bool sdhci_request_done(struct sdhci_host *host)
}
}
- /*
- * The controller needs a reset of internal state machines
- * upon error conditions.
- */
- if (sdhci_needs_reset(host, mrq)) {
- /*
- * Do not finish until command and data lines are available for
- * reset. Note there can only be one other mrq, so it cannot
- * also be in mrqs_done, otherwise host->cmd and host->data_cmd
- * would both be null.
- */
- if (host->cmd || host->data_cmd) {
- spin_unlock_irqrestore(&host->lock, flags);
- return true;
- }
-
- /* Some controllers need this kick or reset won't work here */
- if (host->quirks & SDHCI_QUIRK_CLOCK_BEFORE_RESET)
- /* This is to force an update */
- host->ops->set_clock(host, host->clock);
-
- /* Spec says we should do both at the same time, but Ricoh
- controllers do not like that. */
- sdhci_do_reset(host, SDHCI_RESET_CMD);
- sdhci_do_reset(host, SDHCI_RESET_DATA);
-
- host->pending_reset = false;
- }
-
host->mrqs_done[i] = NULL;
spin_unlock_irqrestore(&host->lock, flags);
--
2.26.2