The branch main has been updated by imp:
URL:
https://cgit.FreeBSD.org/src/commit/?id=e7dc08415a324d1000cd067fbc12b1ec79e0b2ac
commit e7dc08415a324d1000cd067fbc12b1ec79e0b2ac
Author: Austin Shafer <asha...@badland.io>
AuthorDate: 2021-06-03 01:46:23 +0000
Commit: Warner Losh <i...@freebsd.org>
CommitDate: 2021-06-03 01:46:23 +0000
mmc: ignore CRC errors from CMD13 (status) when changing rates
Update mmc_switch_status to ignore a few CRC errrors when asking for the
card status after setting the new rate with CMD6. Since the card may
take a little while to make the switch, it's possible we'll get a
communications error if we sent the command at the wrong time. Several
low end laptops needs this workaround as they have a window that seems
longer than other systems. This is known to fix at least the Acer Aspire
A114-32-P7E5.
Reviewed by: imp@, manu@
Differential Revision: https://reviews.freebsd.org/D24740
---
sys/dev/mmc/mmc_subr.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/sys/dev/mmc/mmc_subr.c b/sys/dev/mmc/mmc_subr.c
index 53c9009c6e64..b43a233820bb 100644
--- a/sys/dev/mmc/mmc_subr.c
+++ b/sys/dev/mmc/mmc_subr.c
@@ -193,7 +193,7 @@ int
mmc_switch_status(device_t busdev, device_t dev, uint16_t rca, u_int timeout)
{
struct timeval cur, end;
- int err;
+ int err, crc_timeout;
uint32_t status;
KASSERT(timeout != 0, ("%s: no timeout", __func__));
@@ -205,7 +205,19 @@ mmc_switch_status(device_t busdev, device_t dev, uint16_t
rca, u_int timeout)
*/
end.tv_sec = end.tv_usec = 0;
for (;;) {
- err = mmc_send_status(busdev, dev, rca, &status);
+ crc_timeout=0;
+ do {
+ /*
+ * CRC errors indicate that the command wasn't accepted
+ * and executed due to a communications error. Retry
+ * CRC errors a couple of times to cope with transient
+ * failures.
+ *
+ * This is required for some cheap laptops to boot.
+ */
+ err = mmc_send_status(busdev, dev, rca, &status);
+ crc_timeout++;
+ } while (err == MMC_ERR_BADCRC && crc_timeout < 10);
if (err != MMC_ERR_NONE)
break;
if (R1_CURRENT_STATE(status) == R1_STATE_TRAN)
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