Hi Christian
On 2021/6/8 14:28, Christian Löhle wrote:
Hey Shawn,
You're assuming a card not signalling busy indicates TRAN state, and set the state manually,
but a card might not be pulling DAT lines in PROG state.
Refer to JESD84-B51 for emmc spec, section 6.5.13 clearly says that. And
SD spec V4 also has a similar statement in section 4.3.4.
So I guess if that was the case you point out, most of all operations in
mmc_ops.c would suffer from this.
I will send a patch later that reworks card_busy_detect, as there are some issues
with some command sequences in practice. I'd ask to wait with the patch until then.
Regards,
Christian
From: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
Sent: Monday, June 7, 2021 11:18 AM
To: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Cc: linux-mmc@xxxxxxxxxxxxxxx <linux-mmc@xxxxxxxxxxxxxxx>; Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
Subject: [PATCH] mmc: block: Use .card_busy() to detect busy state in card_busy_detect
No need to send CMD13 if host driver supports .card_busy().
Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
---
drivers/mmc/core/block.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 88f4c215..23623a9 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -417,10 +417,17 @@ static int card_busy_detect(struct mmc_card *card, unsigned int timeout_ms,
unsigned long timeout = jiffies + msecs_to_jiffies(timeout_ms);
int err = 0;
u32 status;
+ bool busy;
do {
bool done = time_after(jiffies, timeout);
+ if (card->host->ops->card_busy) {
+ busy = card->host->ops->card_busy(card->host);
+ status = busy ? 0 : R1_READY_FOR_DATA | R1_STATE_TRAN << 9;
+ goto cb;
+ }
+
err = __mmc_send_status(card, &status, 5);
if (err) {
dev_err(mmc_dev(card->host),
@@ -442,6 +449,7 @@ static int card_busy_detect(struct mmc_card *card, unsigned int timeout_ms,
__func__, status);
return -ETIMEDOUT;
}
+cb:
} while (!mmc_ready_for_data(status));
return err;
