[PATCH] mmc: dw_mmc: fix dw_mci_get_cd
From: Russell King - ARM Linux <hidden>
Date: 2014-01-15 15:59:19
Also in:
linux-mmc
On Wed, Jan 15, 2014 at 11:51:01PM +0800, Zhangfei Gao wrote:
quoted hunk ↗ jump to hunk
Introduced from commit bf626e5550f24aec24975a0e85ad8e572ca76a6b CDETECT is ignored since negated return value of mmc_gpio_get_cd(mmc) can not be checked by IS_ERR_VALUE. Add spin_lock_bh(&host->lock) for atomic accessing DW_MMC_CARD_PRESENT, otherwise sd detect may occasionally fail. Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org> Reported-by: Kevin Hilman <redacted> Reviewed-by: Sachin Kamat <redacted> Tested-by: Sachin Kamat <redacted> --- drivers/mmc/host/dw_mmc.c | 12 +++++++++--- include/linux/mmc/dw_mmc.h | 1 + 2 files changed, 10 insertions(+), 3 deletions(-)diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index a776f24f4311..8326e54b96a8 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c@@ -1033,7 +1033,8 @@ static int dw_mci_get_cd(struct mmc_host *mmc) int present; struct dw_mci_slot *slot = mmc_priv(mmc); struct dw_mci_board *brd = slot->host->pdata; - int gpio_cd = !mmc_gpio_get_cd(mmc); + struct dw_mci *host = slot->host; + int gpio_cd = mmc_gpio_get_cd(mmc); /* Use platform get_cd function, else try onboard card detect */ if (brd->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)@@ -1041,11 +1042,12 @@ static int dw_mci_get_cd(struct mmc_host *mmc) else if (brd->get_cd) present = !brd->get_cd(slot->id); else if (!IS_ERR_VALUE(gpio_cd)) - present = !!gpio_cd; + present = gpio_cd ^ brd->cd_inverted;
I assume you haven't read the contents of mmc_gpio_get_cd()?
int mmc_gpio_get_cd(struct mmc_host *host)
{
struct mmc_gpio *ctx = host->slot.handler_priv;
if (!ctx || !gpio_is_valid(ctx->cd_gpio))
return -ENOSYS;
return !gpio_get_value_cansleep(ctx->cd_gpio) ^
!!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH);
}
EXPORT_SYMBOL(mmc_gpio_get_cd);
What facility does host->caps2 give you here? Yes, you don't need
your own cd_inverted stuff. You should check that you're interpreting
this correctly. When this returns true, there is a card present.
When MMC_CAP2_CD_ACTIVE_HIGH is set, gpio_get_value_cansleep() must
return non-zero when a card is inserted. When it isn't set,
gpio_get_value_cansleep must return zero when a card is inserted.
--
FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up. Estimation
in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad.
Estimate before purchase was "up to 13.2Mbit".