From: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
Historically, we have been using MMC_CAP* to solve
some issues, and current mmc block.c has
MMC_CAP2_NO_MULTI_READ flag for multi I/O HW bug workaround.
But it should be implemented under driver, not framework.
This patch is prepare for it
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
---
v2 -> v3
- blk_size_workaround -> multi_io_quirk
- fixup comment/explain
- use MMC_DATA_READ/WRITE
drivers/mmc/card/block.c | 10 ++++++++++
include/linux/mmc/host.h | 7 +++++++
2 files changed, 17 insertions(+)
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..bfcf673 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;
--
1.7.9.5
--
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