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@xxxxxxxxxxxxxx> --- 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
-- Best Regards Shawn Lin -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
