From: Pradeep P V K <pragalla@xxxxxxxxxxxxxx> commit 21e35e898aa9ef7781632959db8613a5380f2eae upstream. 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@xxxxxxxxxxxxxx> Signed-off-by: Pradeep P V K <pragalla@xxxxxxxxxxxxxx> Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx> Link: https://lore.kernel.org/r/1614760331-43499-1-git-send-email-pragalla@xxxxxxxxxxxxxxxx Cc: stable@xxxxxxxxxxxxxxx # v4.9+ Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/mmc/host/sdhci.c | 60 ++++++++++++++++++++++++----------------------- 1 file changed, 31 insertions(+), 29 deletions(-) --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -2648,6 +2648,37 @@ static bool sdhci_request_done(struct sd } /* + * 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. * This avoids leaking DMA mappings on error. @@ -2699,35 +2730,6 @@ static bool sdhci_request_done(struct sd } } - /* - * 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);
