From 14efd957209461bbdf285bf0d67e931955d04a4c Mon Sep 17 00:00:00 2001 From: Chris Ball Date: Mon, 5 Nov 2012 14:29:49 -0500 Subject: [PATCH] mmc: sdhci: fix NULL dereference in sdhci_request() tuning Commit 473b095a72a9 ("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 Cc: stable [3.3+] --- drivers/mmc/host/sdhci.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 949e18c7c05d..c7851c0aabce 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -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))