On 5/31/23 15:08, Christian Loehle wrote:
One thing that comes to my mind that would explain the behavior, since all commands itself complete fine is:
Issuing sd cache flush:
[ 61.992588] mmc1: starting CMD49 arg 10020a00 flags 00000035
[ 61.998152] mmc1: blksz 512 blocks 1 flags 00000100 tsac 3000 ms
nsac 0
[ 62.005158] mmci-pl18x 58005000.mmc: blksz 0200 blks 0001 flags 00000100
[ 62.011778] mmci-pl18x 58005000.mmc: op 31 arg 10020a00 flags 00000035
[ 62.018317] mmci-pl18x 58005000.mmc: irq0 (data+cmd) 00000040
[ 62.024011] mmci-pl18x 58005000.mmc: irq0 (data+cmd) 00000100
[ 62.029801] mmc1: req done (CMD49): 0: 00000900 00000000 00000000
00000000
[ 62.036708] mmc1: 512 bytes transferred: 0
[ 62.041083] mmci-pl18x 58005000.mmc: irq0 (data+cmd) 00000000
[ 62.046988] mmc1: starting CMD48 arg 10020a00 flags 000000b5
[ 62.052487] mmc1: blksz 512 blocks 1 flags 00000200 tsac 100 ms
nsac 0
[ 62.059443] mmci-pl18x 58005000.mmc: blksz 0200 blks 0001 flags 00000200
[ 62.066154] mmci-pl18x 58005000.mmc: op 30 arg 10020a00 flags 000000b5
[ 62.072688] mmci-pl18x 58005000.mmc: irq0 (data+cmd) 00000040
[ 62.078382] mmci-pl18x 58005000.mmc: irq0 (data+cmd) 00000100
The kernel reads back the page to ensure it has completed.
[ 62.084173] mmc1: req done (CMD48): 0: 00000900 00000000 00000000
00000000
[ 62.091081] mmc1: 512 bytes transferred: 0
[ 62.095455] mmci-pl18x 58005000.mmc: irq0 (data+cmd) 00000000
[ 62.101381] I/O error, dev mmcblk1, sector 8192 op 0x1:(WRITE) flags
0x800 phys_seg 1 prio class 2
Fail here implies that it did indeed fail right after CMD48.
I would expect a card that does not hold down busy the entire cache flush time would produce the observed behavior.
The CMD48 is issued ~100ms after the CMD49, so not nearly close to the timeout of 1s.
That is just one possibility of course, it would need a full trace to confirm.
What kind of trace ?
For you easier probably something like:
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 72b664ed90cf..c9d3cae0678d 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -1354,8 +1354,11 @@ static int sd_flush_cache(struct mmc_host *host)
goto out;
}
- if (reg_buf[0] & BIT(0))
+ if (reg_buf[0] & BIT(0)) {
+ pr_warn("%s: Cache Flush bit still active after busy phase\n",
+ mmc_hostname(host));
err = -ETIMEDOUT;
+ }
Adrian provided a bit more complete patch, I tested that, see my reply
there.
