| Message ID | 1389770159-21125-1-git-send-email-zhangfei.gao@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
Hi Kevin Would you mind check whehter this patch solve the issue of "The Samsung Arndale board started failing boot from MMC". I am sorry about that. On 01/15/2014 03:15 PM, Zhangfei Gao wrote: > Introdeced from commit b7db86adfa58b commit should be bf626e5550f24aec24975a0e85ad8e572ca76a6b, from mmc-next > CDETECT is ingored since IS_ERR_VALUE(!mmc_gpio_get_cd(mmc)) does not work > Add spin_lock_bh(&host->lock) for atomic accessing DW_MMC_CARD_PRESENT > > Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org> > Reported-by: Kevin Hilman <khilman@linaro.org> > --- > drivers/mmc/host/dw_mmc.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-)
On 01/16/2014 12:22 AM, Russell King - ARM Linux wrote: > Well, having this in the gpio level as well as in subsystems like MMC > is going to create confusion - and from the results of this patch _IS_ > causing confusion. You've just encouraged one implementation to have > things setup such that mmc_gpio_get_cd() returns false when a card is > inserted, rather than it correctly returning true. > > The issue here is that we'll potentially now end up with _three_ > inversions. One in the GPIO layers. One in mmc_gpio_get_cd(), and > another in every driver which uses the GPIO layer inversion. This > is hardly the right approach as it leads to multiple points where > confusion about the inverted status can occur. > Thanks Russell, make sense. Double checked with the hardware guy, cd pin is high when card inserted on the board. The cd pin is originally connected to vout via a resister, and internally short to gound, which is broken when card inserted. Then Optional properties "caps2-mmc-cd-active-high" has to be added. --- a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt +++ b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt +* caps2-mmc-cd-active-high: cd pin is high when card present @@ -2411,6 +2414,9 @@ static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host) if (of_find_property(np, "caps2-mmc-hs200-1_2v", NULL)) pdata->caps2 |= MMC_CAP2_HS200_1_2V_SDR; + if (of_find_property(np, "caps2-mmc-cd-active-high", NULL)) + pdata->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH; + Thanks
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index a776f24f4311..9ded62c8225e 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; else present = (mci_readl(slot->host, CDETECT) & (1 << slot->id)) == 0 ? 1 : 0; + spin_lock_bh(&host->lock); if (present) { set_bit(DW_MMC_CARD_PRESENT, &slot->flags); dev_dbg(&mmc->class_dev, "card is present\n"); @@ -1053,6 +1055,7 @@ static int dw_mci_get_cd(struct mmc_host *mmc) clear_bit(DW_MMC_CARD_PRESENT, &slot->flags); dev_dbg(&mmc->class_dev, "card is not present\n"); } + spin_unlock_bh(&host->lock); return present; } @@ -2081,7 +2084,7 @@ static int dw_mci_of_get_wp_gpio(struct device *dev, u8 slot) return gpio; } -/* find the cd gpio for a given slot; or -1 if none specified */ +/* find the cd gpio for a given slot */ static void dw_mci_of_get_cd_gpio(struct device *dev, u8 slot, struct mmc_host *mmc) {
Introdeced from commit b7db86adfa58b CDETECT is ingored since IS_ERR_VALUE(!mmc_gpio_get_cd(mmc)) does not work Add spin_lock_bh(&host->lock) for atomic accessing DW_MMC_CARD_PRESENT Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org> Reported-by: Kevin Hilman <khilman@linaro.org> --- drivers/mmc/host/dw_mmc.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)