Hi, greetings,
I think below line has a bug in core.c.
According to SD specification, the maximum identification frequency is
400 KHz (physical_layer_2.0.pdf, page 123).
But the original code would set higher than 400 KHz if the f_min is
higher than 400 KHz. Conversely, if f_min is lower than 400 KHz, it is
always set as 400 KHz. This is wrong also.
========================================================
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 3168ebd..0cf7e5c 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -907,7 +907,7 @@ static void mmc_power_up(struct mmc_host *host)
*/
mmc_delay(10);
- if (host->f_min > 400000) {
+ if (host->f_min < 400000) {
pr_warning("%s: Minimum clock frequency too high for "
"identification mode\n", mmc_hostname(host));
host->ios.clock = host->f_min;
===========================================================
Best regards,
Fred
Attachment:
0001-mmc-Maximum-frequency-of-identification-mode-is-400-.patch
Description: Binary data
