On 2 September 2014 04:01, Kuninori Morimoto
<kuninori.morimoto.gx@xxxxxxxxx> wrote:
> From: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
>
> Current mmc block.c has MMC_CAP2_NO_MULTI_READ flag
> for HW bug workaround, but it should be implemented
> under driver, not framework.
> This patch is prepare for it
I like the idea of this patchset!
Still, historically, we have been using MMC_CAP* to solve these kind
issues. Therefore I think the commit message deserves a better
explanation to why we invent a new host ops function pointer for this
particular case.
>
> Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
> ---
> v1 -> v2
>
> - no change
>
> drivers/mmc/card/block.c | 5 +++++
> include/linux/mmc/host.h | 4 ++++
> 2 files changed, 9 insertions(+)
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index ede41f0..e946067 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -1402,6 +1402,11 @@ static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
> if (card->host->caps2 & MMC_CAP2_NO_MULTI_READ &&
> rq_data_dir(req) == READ)
> brq->data.blocks = 1;
> +
> + /* Some controllers needs workaround */
Suggest to rephrase the comment to:
"Some controllers have HW issues while operating in multiple I/O mode."
> + if (card->host->ops->blk_size_workaround)
Do you mind renaming the new callback to "multi_io_quirk"? I think it
better describes what it's intended for.
> + brq->data.blocks = card->host->ops->blk_size_workaround(
> + card, req, brq->data.blocks);
We shouldn't pass "req" as an argument, since that is a blkdev
specific struct. It's better to pass MMC_DATA_WRITE|READ as an
unsigned int.
> }
>
> if (brq->data.blocks > 1 || do_rel_wr) {
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 4cbf614..95bd903 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -139,6 +139,10 @@ struct mmc_host_ops {
> int (*select_drive_strength)(unsigned int max_dtr, int host_drv, int card_drv);
> void (*hw_reset)(struct mmc_host *host);
> void (*card_event)(struct mmc_host *host);
> +
> + /* optional callback for mmc block HW bug workaround */
Please update the comment to something like below:
"Optional callback to support controllers with HW issues for multiple I/O.
Returns the number of supported blocks for the request."
> + int (*blk_size_workaround)(struct mmc_card *card,
> + struct request *req, int blk_size);
> };
>
> struct mmc_card;
> --
> 1.7.9.5
>
Kind regards
Uffe
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
