mmc: sdhci: fix NULL dereference in sdhci_request() tuning

Commit 473b095a72 ("mmc: sdhci: fix incorrect command used in tuning")
introduced a NULL dereference at resume-time if an SD 3.0 host controller
raises the SDHCI_NEEDS_TUNING flag while no card is inserted.  Seen on an
OLPC XO-4 with sdhci-pxav3, but presumably affects other controllers too.

Signed-off-by: Chris Ball <cjb@laptop.org>
Cc: stable <stable@vger.kernel.org> [3.3+]
This commit is contained in:
Chris Ball 2012-11-05 14:29:49 -05:00
parent 657d59823c
commit 14efd95720

View File

@ -1315,16 +1315,19 @@ static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
*/
if ((host->flags & SDHCI_NEEDS_RETUNING) &&
!(present_state & (SDHCI_DOING_WRITE | SDHCI_DOING_READ))) {
/* eMMC uses cmd21 while sd and sdio use cmd19 */
tuning_opcode = mmc->card->type == MMC_TYPE_MMC ?
MMC_SEND_TUNING_BLOCK_HS200 :
MMC_SEND_TUNING_BLOCK;
spin_unlock_irqrestore(&host->lock, flags);
sdhci_execute_tuning(mmc, tuning_opcode);
spin_lock_irqsave(&host->lock, flags);
if (mmc->card) {
/* eMMC uses cmd21 but sd and sdio use cmd19 */
tuning_opcode =
mmc->card->type == MMC_TYPE_MMC ?
MMC_SEND_TUNING_BLOCK_HS200 :
MMC_SEND_TUNING_BLOCK;
spin_unlock_irqrestore(&host->lock, flags);
sdhci_execute_tuning(mmc, tuning_opcode);
spin_lock_irqsave(&host->lock, flags);
/* Restore original mmc_request structure */
host->mrq = mrq;
/* Restore original mmc_request structure */
host->mrq = mrq;
}
}
if (mrq->sbc && !(host->flags & SDHCI_AUTO_CMD23))