On 11/06/21 12:03 pm, Takashi Iwai wrote:
> When DMA-mapping of the bounce buffer fails, the driver tries to fall
> back, but it leaves the allocated host->bounce_buffer although its
> size is zero. Later on, the driver checks the use of bounce buffer
> with host->bounce_buffer pointer, and it tries to use the buffer
> incorrectly, resulting in Oops.
>
> This patch clears the release the unused buffer and clears the
> bounce_buffer pointer for addressing the problem.
>
> Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
One minor comment below, otherwise:
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
> drivers/mmc/host/sdhci.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index bf238ade1602..5f467b98ca88 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -4072,9 +4072,13 @@ static void sdhci_allocate_bounce_buffer(struct sdhci_host *host)
> bounce_size,
> DMA_BIDIRECTIONAL);
> ret = dma_mapping_error(mmc_dev(mmc), host->bounce_addr);
> - if (ret)
> + if (ret) {
> + devm_kfree(mmc->parent, host->bounce_buffer);
Everywhere else in this function mmc_dev(mmc) is used, so maybe
use it here too instead of mmc->parent.
> + host->bounce_buffer = NULL;
> /* Again fall back to max_segs == 1 */
> return;
> + }
> +
> host->bounce_buffer_size = bounce_size;
>
> /* Lie about this since we're bouncing */
>
