On 2018/5/25 17:02, Ulf Hansson wrote:
On 25 May 2018 at 08:18, Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> wrote:Per JESD85-B51, section 6.6.8.1, it says "Some Devices may require long and unpredictable times to write a block of data. After receiving a block of data and completing the CRC check, the Device will begin writing and hold the DAT0 line low. The host may poll the status of the Device with a SEND_STATUS command(CMD13) at any time, and the Device will respond with its status (except in Sleep state). The status bit READY_FOR_DATA indicates whether the Device can accept new data or not." That describes the busy condition for data write that we should consider R1_READY_FOR_DATA as a busy indication. And R1_READY_FOR_DATA shouldn't happen as well when doing switch and erase stuff, Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> --- drivers/mmc/core/mmc_ops.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c index 959b8cd..1288802 100644 --- a/drivers/mmc/core/mmc_ops.c +++ b/drivers/mmc/core/mmc_ops.c @@ -507,7 +507,8 @@ static int mmc_poll_for_busy(struct mmc_card *card, unsigned int timeout_ms, err = mmc_send_status_error(host, status, true); if (err) return err; - busy = R1_CURRENT_STATE(status) == R1_STATE_PRG; + busy = R1_CURRENT_STATE(status) == R1_STATE_PRG + || !(status & R1_READY_FOR_DATA);This makes sense, only that it may have a little impact on performance. Thinking if R1_READY_FOR_DATA takes a little longer to be raised rather than only de-asserting R1_STATE_PRG bit. On this other hand, so far I don't think there are any real performance critical callers of mmc_poll_for_busy(). That may change if you intend to switch card_busy_detect() in block.c to use this polling as well!?
Hmm... that's why I was not changing card_busy_detect(). It means we need a new parameter for what busy indication the callers want, as well as a output status. Well, I will rework it next week along with reusing it for card_busy_detect().
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
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