From 8b0cc8707f65e0f51912e764e1b309b2559db1ec Mon Sep 17 00:00:00 2001 From: Xu Rao Date: Tue, 18 Aug 2026 19:31:53 +0800 Subject: mmc: spi: reset bytes_xfered before retrying CRC failures mmc_spi_data_do() updates data->bytes_xfered after each block has been transferred successfully. If a later block in the same data request fails with a CRC error, data->bytes_xfered may therefore contain the number of bytes completed before the failing block. mmc_spi_request() has a private recovery path for such CRC failures. It sends STOP_TRANSMISSION, clears data->error and jumps back to crc_recover to issue the same command and data request again. However, it does not clear data->bytes_xfered before the retry. If the retry succeeds, the request is completed with the bytes from the failed attempt still included in data->bytes_xfered. For a multi-block request this can make the completed request report more bytes than were transferred by the successful retry, and can even exceed the request size when most blocks completed before the CRC error. This is most likely to be observed on MMC-over-SPI systems where long multi-block transfers occasionally hit a data CRC error but the mmc_spi-internal retry succeeds. The data itself is retried, but the completion accounting is not. Clear data->bytes_xfered together with data->error before repeating the request so the final completion reports only the bytes transferred by the successful attempt. Fixes: 061c6c847eeb ("mmc_spi: Recover from CRC errors for r/w operation over SPI.") Cc: stable@vger.kernel.org Signed-off-by: Xu Rao Signed-off-by: Ulf Hansson --- drivers/mmc/host/mmc_spi.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c index b471a7795b4d..5217d713c826 100644 --- a/drivers/mmc/host/mmc_spi.c +++ b/drivers/mmc/host/mmc_spi.c @@ -952,6 +952,7 @@ crc_recover: status = mmc_spi_command_send(host, mrq, &stop, 0); crc_retry--; mrq->data->error = 0; + mrq->data->bytes_xfered = 0; goto crc_recover; } -- cgit v1.2.3