diff options
| author | Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> | 2014-09-03 02:08:53 (GMT) |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2014-09-09 11:59:25 (GMT) |
| commit | 2e47e84245adcb1b3872210678b6146f674fb3ff (patch) | |
| tree | 0ab356fa3d0d079a855ed65e5b51326328738e99 | |
| parent | adc828556dfc3f87a5c1338fc5412cbec3c0b529 (diff) | |
| download | linux-2e47e84245adcb1b3872210678b6146f674fb3ff.tar.xz | |
mmc: Add .multi_io_quirk callback for multi I/O HW bug
Historically, we have been using MMC_CAP* to handle host HW issues and
currently the block layer uses MMC_CAP2_NO_MULTI_READ flag for a multi
I/O HW bug workaround.
There are a few tweaks needed to make MMC_CAP2_NO_MULTI_READ suite all
situations. Therefore let's add an optional host ops callback to enable
host drivers to return the number of blocks it allows per request.
In a future patch and when host drivers have converted to the new
callback, MMC_CAP2_NO_MULTI_READ shall be removed.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
| -rw-r--r-- | drivers/mmc/card/block.c | 10 | ||||
| -rw-r--r-- | include/linux/mmc/host.h | 7 |
2 files changed, 17 insertions, 0 deletions
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index ede41f0..adab903 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -1402,6 +1402,16 @@ 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 have HW issues while operating + * in multiple I/O mode + */ + if (card->host->ops->multi_io_quirk) + brq->data.blocks = card->host->ops->multi_io_quirk(card, + (rq_data_dir(req) == READ) ? + MMC_DATA_READ : MMC_DATA_WRITE, + brq->data.blocks); } if (brq->data.blocks > 1 || do_rel_wr) { diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 4cbf614..10e2bd6 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -139,6 +139,13 @@ 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 to support controllers with HW issues for multiple + * I/O. Returns the number of supported blocks for the request. + */ + int (*multi_io_quirk)(struct mmc_card *card, + unsigned int direction, int blk_size); }; struct mmc_card; |