From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dong Aisheng Subject: [PATCH 1/3] mmc: core: fix using wrong io voltage if mmc_select_hs200 fails Date: Thu, 21 Apr 2016 00:51:30 +0800 Message-ID: <1461171092-30631-1-git-send-email-aisheng.dong@nxp.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from mail-by2on0067.outbound.protection.outlook.com ([207.46.100.67]:35388 "EHLO na01-by2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751231AbcDTQ7E (ORCPT ); Wed, 20 Apr 2016 12:59:04 -0400 Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: linux-mmc@vger.kernel.org Cc: ulf.hansson@linaro.org, chris@printf.net, shawnguo@kernel.org, adrian.hunter@intel.com, linux-arm-kernel@lists.infradead.org, aisheng.dong@nxp.com, haibo.chen@nxp.com, dongas86@gmail.com Currently MMC core will keep going if HS200/HS timing switch failed with -EBADMSG error by the assumption that the old timing is still valid. However, for mmc_select_hs200 case, the signal voltage may have already been switched. If the timing switch failed, we should fall back to the old voltage in case the card is continue run with legacy timing. If fall back signal voltage failed, we explicitly report an EIO error to force retry during the next power cycle. Signed-off-by: Dong Aisheng --- drivers/mmc/core/mmc.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index b8aa12c..f6683a9 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -1245,9 +1245,11 @@ static int mmc_select_hs200(struct mmc_card *card) struct mmc_host *host = card->host; bool send_status = true; unsigned int old_timing; + unsigned int old_signal_voltage; int err = -EINVAL; u8 val; + old_signal_voltage = host->ios.signal_voltage; if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200_1_2V) err = __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120); @@ -1256,7 +1258,7 @@ static int mmc_select_hs200(struct mmc_card *card) /* If fails try again during next card power cycle */ if (err) - goto err; + return err; mmc_select_driver_type(card); @@ -1290,9 +1292,14 @@ static int mmc_select_hs200(struct mmc_card *card) } } err: - if (err) + if (err) { + /* fall back to the old signal voltage, if fails report error */ + if (__mmc_set_signal_voltage(host, old_signal_voltage)) + err = -EIO; + pr_err("%s: %s failed, error %d\n", mmc_hostname(card->host), __func__, err); + } return err; } -- 1.9.1