Commit d8c3bab30542 ("mci: only write blocks when card out of programming
mode") polls the card status before a block write, so that CMD24/25 is
not sent while the card is still programming the previous write. Reads
are not covered: a read following a write can still find the card in
prg state. CMD17/18 are illegal there and the card does not answer
them, so the host sees a response timeout.On a KSZ9477-EVB (SAMA5D3) with a freshly flashed SD card, the first saveenv fails with: ERROR: atmel_mci [email protected]: command/data timeout ERROR: atmel_mci [email protected]: command/data timeout With more verbose error reporting, the failing commands turn out to be a multi-block read and the stop command sent after it: CMD18: response timeout (SR=0x04100005) CMD12: response timeout (SR=0x04100005) The same happens without any filesystem involved when writing larger amounts of data to the raw device: memcpy -s /dev/ram0 -d /dev/mmc0.root-A 0 0 2M Also poll the card status after each block write, like U-Boot does, so that any command following a write finds the card back in transfer state. Assisted-by: Claude:claude-opus-5-5 Signed-off-by: Sascha Hauer <[email protected]> --- drivers/mci/mci-core.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/mci/mci-core.c b/drivers/mci/mci-core.c index 874ee40cb3..1954de8053 100644 --- a/drivers/mci/mci-core.c +++ b/drivers/mci/mci-core.c @@ -266,7 +266,7 @@ static int mci_block_write(struct mci *mci, const void *src, int blocknum, { struct mci_cmd cmd = {}; unsigned mmccmd; - int ret; + int ret, err; /* * Quoting eMMC Spec v5.1 (JEDEC Standard No. 84-B51): @@ -304,6 +304,15 @@ static int mci_block_write(struct mci *mci, const void *src, int blocknum, mci_send_cmd(mci, &cmd); } + /* + * The card stays in prg state for a while after the write. Polling + * before the next write is not enough: a read sent in prg state is + * an illegal command, which the card does not answer at all. + */ + err = mci_poll_until_ready(mci, 1000 /* ms */); + if (!ret && err != -ENOSYS) + ret = err; + return ret; } -- 2.47.3
