On Wed, 10 Jul 2024 at 20:09, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
>
> blk_queue_max_segment_size() ensured:
>
> if (max_size < PAGE_SIZE)
> max_size = PAGE_SIZE;
>
> whereas:
>
> blk_validate_limits() makes it an error:
>
> if (WARN_ON_ONCE(lim->max_segment_size < PAGE_SIZE))
> return -EINVAL;
>
> The change from one to the other, exposed sdhci which was setting maximum
> segment size too low in some circumstances.
>
> Fix the maximum segment size when it is too low.
>
> Fixes: 616f87661792 ("mmc: pass queue_limits to blk_mq_alloc_disk")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Applied for fixes, thanks!
If we want to log a message due to the wrong max_seg_size, let's do
that from a patch on top.
Kind regards
Uffe
> ---
> drivers/mmc/host/sdhci.c | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index a20df9383b20..4b91c9e96635 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -4708,6 +4708,21 @@ int sdhci_setup_host(struct sdhci_host *host)
> if (host->quirks & SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC) {
> host->max_adma = 65532; /* 32-bit alignment */
> mmc->max_seg_size = 65535;
> + /*
> + * sdhci_adma_table_pre() expects to define 1 DMA
> + * descriptor per segment, so the maximum segment size
> + * is set accordingly. SDHCI allows up to 64KiB per DMA
> + * descriptor (16-bit field), but some controllers do
> + * not support "zero means 65536" reducing the maximum
> + * for them to 65535. That is a problem if PAGE_SIZE is
> + * 64KiB because the block layer does not support
> + * max_seg_size < PAGE_SIZE, however
> + * sdhci_adma_table_pre() has a workaround to handle
> + * that case, and split the descriptor. Refer also
> + * comment in sdhci_adma_table_pre().
> + */
> + if (mmc->max_seg_size < PAGE_SIZE)
> + mmc->max_seg_size = PAGE_SIZE;
> } else {
> mmc->max_seg_size = 65536;
> }
> --
> 2.34.1
>
