From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753229AbcEZDIe (ORCPT ); Wed, 25 May 2016 23:08:34 -0400 Received: from lucky1.263xmail.com ([211.157.147.131]:46226 "EHLO lucky1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753095AbcEZDId (ORCPT ); Wed, 25 May 2016 23:08:33 -0400 X-263anti-spam: KSV:0; X-MAIL-GRAY: 1 X-MAIL-DELIVERY: 0 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-ADDR-CHECKED: 0 X-RL-SENDER: shawn.lin@rock-chips.com X-FST-TO: jh80.chung@samsung.com X-SENDER-IP: 58.22.7.114 X-LOGIN-NAME: shawn.lin@rock-chips.com X-UNIQUE-TAG: X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 From: Shawn Lin To: Jaehoon Chung , Ulf Hansson Cc: linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, Doug Anderson , linux-rockchip@lists.infradead.org, Shawn Lin Subject: [RFC PATCH 2/2] mmc: dw_mmc: check card present before starting request Date: Thu, 26 May 2016 11:08:11 +0800 Message-Id: <1464232091-24882-1-git-send-email-shawn.lin@rock-chips.com> X-Mailer: git-send-email 1.8.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The main reason to add this check is to avoid unnecessary mmc_request if the card is removed. Although we have already check 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 --- drivers/mmc/host/dw_mmc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index cb30e91..2940d24 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) @@ -1248,6 +1249,8 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq) WARN_ON(slot->mrq); + dw_mci_get_cd(mmc); + /* * The check for card presence and queueing of the request must be * atomic, otherwise the card could be removed in between and the -- 2.3.7