| Message ID | 1464331025-16275-1-git-send-email-shawn.lin@rock-chips.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Shawn, On 05/27/2016 03:37 PM, Shawn Lin wrote: > The main reason to add this check is to avoid unnecessary > mmc_request like the on-going cmd and the corresponding sbc > if the card is removed. Although we have already checked this in > dw_mci_handle_cd for runtime usage of sd card and dw_mci_init_slot > for noremovable devices, but there is a timing gap before it really > calls dw_mci_get_cd as mmc_detect_change needs some delay here. > > Another gain here is that we could save some checkings of card status > after sd card been removed. > > Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> Applied on my repository. Thanks! Best Regards, Jaehoon Chung > > --- > > Changes in v2: > - hold lock before dw_mci_queue_request > > drivers/mmc/host/dw_mmc.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c > index cb30e91..2b4b3df 100644 > --- a/drivers/mmc/host/dw_mmc.c > +++ b/drivers/mmc/host/dw_mmc.c > @@ -105,6 +105,7 @@ struct idmac_desc { > static bool dw_mci_reset(struct dw_mci *host); > static bool dw_mci_ctrl_reset(struct dw_mci *host, u32 reset); > static int dw_mci_card_busy(struct mmc_host *mmc); > +static int dw_mci_get_cd(struct mmc_host *mmc); > > #if defined(CONFIG_DEBUG_FS) > static int dw_mci_req_show(struct seq_file *s, void *v) > @@ -1253,15 +1254,15 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq) > * atomic, otherwise the card could be removed in between and the > * request wouldn't fail until another card was inserted. > */ > - spin_lock_bh(&host->lock); > > - if (!test_bit(DW_MMC_CARD_PRESENT, &slot->flags)) { > - spin_unlock_bh(&host->lock); > + if (!dw_mci_get_cd(mmc)) { > mrq->cmd->error = -ENOMEDIUM; > mmc_request_done(mmc, mrq); > return; > } > > + spin_lock_bh(&host->lock); > + > dw_mci_queue_request(host, slot, mrq); > > spin_unlock_bh(&host->lock); > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index cb30e91..2b4b3df 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -105,6 +105,7 @@ struct idmac_desc { static bool dw_mci_reset(struct dw_mci *host); static bool dw_mci_ctrl_reset(struct dw_mci *host, u32 reset); static int dw_mci_card_busy(struct mmc_host *mmc); +static int dw_mci_get_cd(struct mmc_host *mmc); #if defined(CONFIG_DEBUG_FS) static int dw_mci_req_show(struct seq_file *s, void *v) @@ -1253,15 +1254,15 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq) * atomic, otherwise the card could be removed in between and the * request wouldn't fail until another card was inserted. */ - spin_lock_bh(&host->lock); - if (!test_bit(DW_MMC_CARD_PRESENT, &slot->flags)) { - spin_unlock_bh(&host->lock); + if (!dw_mci_get_cd(mmc)) { mrq->cmd->error = -ENOMEDIUM; mmc_request_done(mmc, mrq); return; } + spin_lock_bh(&host->lock); + dw_mci_queue_request(host, slot, mrq); spin_unlock_bh(&host->lock);
The main reason to add this check is to avoid unnecessary mmc_request like the on-going cmd and the corresponding sbc if the card is removed. Although we have already checked this in dw_mci_handle_cd for runtime usage of sd card and dw_mci_init_slot for noremovable devices, but there is a timing gap before it really calls dw_mci_get_cd as mmc_detect_change needs some delay here. Another gain here is that we could save some checkings of card status after sd card been removed. Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> --- Changes in v2: - hold lock before dw_mci_queue_request drivers/mmc/host/dw_mmc.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)