From: Wolfgang Muees Date: Tue, 22 Sep 2009 23:45:26 +0000 (-0700) Subject: mmc_spi: fail gracefully if host or card do not support the switch command X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=d08ebeddfb3293fa4bdfca9c610daf1e8ec8b233;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git mmc_spi: fail gracefully if host or card do not support the switch command Some time ago, I have send a patch to the mmc_spi subsystem changing the error codes. This was after a discussion with Pierre about using EINVAL only for non-recoverable errors. This patch was accepted as http://git.kernel.org/linus/fdd858db7113ca64132de390188d7ca00701013d Unfortunately, several weeks later, I realized that this patch has opened a little can of worms because there are SD cards on the market which a) claim that they support the switch command AND b) refuse to execute this command if operating in SPI mode. So, such a card would get unusuable in an embedded linux system in SPI mode, because the init sequence terminates with an error. This patch adds the missing error codes to the caller of the switch command and restores the old behaviour to fail gracefully if these commands can not execute. Signed-off-by: Wolfgang Muees Cc: Cc: [2.6.31.x] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index a6b5fe9d3969..ddddad46b402 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -179,11 +179,11 @@ static int mmc_read_ext_csd(struct mmc_card *card) err = mmc_send_ext_csd(card, ext_csd); if (err) { - /* - * We all hosts that cannot perform the command - * to fail more gracefully - */ - if (err != -EINVAL) + /* If the host or the card can't do the switch, + * fail more gracefully. */ + if ((err != -EINVAL) + && (err != -ENOSYS) + && (err != -EFAULT)) goto out; /* diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index 222a60928cdb..13b3a6b8f5b5 100644 --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -210,11 +210,11 @@ static int mmc_read_switch(struct mmc_card *card) err = mmc_sd_switch(card, 0, 0, 1, status); if (err) { - /* - * We all hosts that cannot perform the command - * to fail more gracefully - */ - if (err != -EINVAL) + /* If the host or the card can't do the switch, + * fail more gracefully. */ + if ((err != -EINVAL) + && (err != -ENOSYS) + && (err != -EFAULT)) goto out; printk(KERN_WARNING "%s: problem reading switch "