Function bcm_2835_wait_transfer_complete() on driver/mmc/bcm2835_sdhost.c (used on Raspberry Pi platform), was not waiting long enough for transfer to complete. The previous code was claiming to wait for ~1 seconds, but my measurements on a RPi 3B+ indicated a maximum wait of 12 ms. Measured using get_tiimer() function. Some, but not all, of the cards we use, sometimes required wait times of ~56 ms to perform the command 'saveenv' on an EXT4 partition. (the exact operation being a CMD25 write of the superblock of EXT4).
Re-implemented the loop exit condition to use get_timer() which allows to specify the wait time in more reliable manner. Set the maximum wait time to the originally intended 1 second.
Signed-off by: Raul Benet <raul.benet_at_kaptivo.com>
--- drivers/mmc/bcm2835_sdhost.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/mmc/bcm2835_sdhost.c b/drivers/mmc/bcm2835_sdhost.c index 1ce019a..96e06b8 100644 --- a/drivers/mmc/bcm2835_sdhost.c +++ b/drivers/mmc/bcm2835_sdhost.c @@ -234,7 +234,7 @@ static void bcm2835_reset_internal(struct bcm2835_host *host)
static int bcm2835_wait_transfer_complete(struct bcm2835_host *host) { - int timediff = 0; + ulong tstart_ms = get_timer(0);
while (1) { u32 edm, fsm; @@ -254,11 +254,12 @@ static int bcm2835_wait_transfer_complete(struct bcm2835_host *host) break; }
- /* Error out after 100000 register reads (~1s) */ - if (timediff++ == 100000) { + /* Error out after ~1s */ + ulong tlapse_ms = get_timer(tstart_ms); + if ( tlapse_ms > 1000 /* ms */ ) { dev_err(host->dev, - "wait_transfer_complete - still waiting after %d retries\n", - timediff); + "wait_transfer_complete - still waiting after %lu ms\n", + tlapse_ms); bcm2835_dumpregs(host); return -ETIMEDOUT; }