From 71fcbda0fcddd0896c4982a484f6c8aa802d28b1 Mon Sep 17 00:00:00 2001 From: Russell King Date: Tue, 26 Jan 2016 13:39:45 +0000 Subject: [PATCH] mmc: sdhci: fix command response CRC error handling When we get a response CRC error on a command, it means that the response we received back from the card was not correct. It does not mean that the card did not receive the command correctly. If the command is one which initiates a data transfer, the card can enter the data transfer state, and start sending data. Moreover, if the request contained a data phase, we do not clean this up, and this results in the driver triggering DMA API debug warnings, and also creates a race condition in the driver, between running the finish_tasklet and the data transfer interrupts, which can trigger a "Got data interrupt" state dump. Fix this by handing a response CRC error slightly differently: record the failure of the data initiating command, but allow the remainder of the request to be processed normally. This is safe as core MMC checks the status of all commands and data transfer phases of the request. If the card does not initiate a data transfer, then we should time out according to the data transfer parameters. Signed-off-by: Russell King [ Fix missing parenthesis around bitwise-AND expression, and tweak subject ] Signed-off-by: Adrian Hunter Cc: stable@vger.kernel.org # v4.5+ Tested-by: Gregory CLEMENT Signed-off-by: Ulf Hansson --- drivers/mmc/host/sdhci.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index b261613224f6..5c90941f31d9 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -2330,6 +2330,23 @@ static void sdhci_cmd_irq(struct sdhci_host *host, u32 intmask, u32 *mask) else host->cmd->error = -EILSEQ; + /* + * If this command initiates a data phase and a response + * CRC error is signalled, the card can start transferring + * data - the card may have received the command without + * error. We must not terminate the mmc_request early. + * + * If the card did not receive the command or returned an + * error which prevented it sending data, the data phase + * will time out. + */ + if (host->cmd->data && + (intmask & (SDHCI_INT_CRC | SDHCI_INT_TIMEOUT)) == + SDHCI_INT_CRC) { + host->cmd = NULL; + return; + } + tasklet_schedule(&host->finish_tasklet); return; } -- 2.20.1