| Message ID | 1464318141-5360-1-git-send-email-shawn.lin@rock-chips.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Shawn, On 05/27/2016 12:02 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> > --- > > drivers/mmc/host/dw_mmc.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c > index cb30e91..8eb7898 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) > @@ -1255,7 +1256,7 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq) > */ > spin_lock_bh(&host->lock); > > - if (!test_bit(DW_MMC_CARD_PRESENT, &slot->flags)) { > + if (!dw_mci_get_cd(mmc)) { > spin_unlock_bh(&host->lock); > mrq->cmd->error = -ENOMEDIUM; > mmc_request_done(mmc, mrq); I think spin_lock/unlock_bh() should be removed at here. Instead, Can it locate before calling dw_mci_queue_request()? Anyway, it looks good to me. Best Regards, Jaehoon Chung > -- 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
在 2016/5/27 11:46, Jaehoon Chung 写道: > Hi Shawn, > > On 05/27/2016 12:02 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> >> --- >> >> drivers/mmc/host/dw_mmc.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c >> index cb30e91..8eb7898 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) >> @@ -1255,7 +1256,7 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq) >> */ >> spin_lock_bh(&host->lock); >> >> - if (!test_bit(DW_MMC_CARD_PRESENT, &slot->flags)) { >> + if (!dw_mci_get_cd(mmc)) { >> spin_unlock_bh(&host->lock); >> mrq->cmd->error = -ENOMEDIUM; >> mmc_request_done(mmc, mrq); > > I think spin_lock/unlock_bh() should be removed at here. yes, we should hole the lock before dw_mci_queue_request as dw_mci_get_cd release it, in which state we do the minmum changes for achieving what we need here. I will fix it. > Instead, Can it locate before calling dw_mci_queue_request()? > > Anyway, it looks good to me. > > Best Regards, > Jaehoon Chung > >> > > > >
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index cb30e91..8eb7898 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) @@ -1255,7 +1256,7 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq) */ spin_lock_bh(&host->lock); - if (!test_bit(DW_MMC_CARD_PRESENT, &slot->flags)) { + if (!dw_mci_get_cd(mmc)) { spin_unlock_bh(&host->lock); mrq->cmd->error = -ENOMEDIUM; mmc_request_done(mmc, mrq);
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> --- drivers/mmc/host/dw_mmc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)