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FROMGIT: mmc: sdhci: Check for reset prior to DMA address unmap

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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().

Bug: 186781699
(cherry picked from commit 21e35e898a
git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc.git remotes/origin/next)
Link: https://lore.kernel.org/r/1614760331-43499-1-git-send-email-pragalla@qti.qualcomm.com

Suggested-by: Veerabhadrarao Badiganti <vbadigan@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>
Signed-off-by: Pradeep P V K <pragalla@codeaurora.org>
Signed-off-by: Bao D. Nguyen <nguyenb@codeaurora.org>
Change-Id: I547ea7c1b3e2b9026313d6e17b09851eef520c22
This commit is contained in:
Pradeep P V K 2021-03-03 14:02:11 +05:30 • committed by Todd Kjos
commit 514f06c0b0
1 changed files with 31 additions and 29 deletions
Download patch file Download diff file Expand all files Collapse all files

60
drivers/mmc/host/sdhci.c
View file

@ -2997,6 +2997,37 @@ 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.
@ -3060,35 +3091,6 @@ 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);