From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Stultz Subject: [PATCH 4/6] mmc: sd: Add new CONFIG_MMC_PARANOID_SD_INIT for enabling retries during SD detection Date: Fri, 22 Apr 2011 18:01:40 -0700 Message-ID: <1303520502-32171-5-git-send-email-john.stultz@linaro.org> References: <1303520502-32171-1-git-send-email-john.stultz@linaro.org> Return-path: Received: from e1.ny.us.ibm.com ([32.97.182.141]:36483 "EHLO e1.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757054Ab1DWBBz (ORCPT ); Fri, 22 Apr 2011 21:01:55 -0400 Received: from d01relay03.pok.ibm.com (d01relay03.pok.ibm.com [9.56.227.235]) by e1.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p3N0pCCb003108 for ; Fri, 22 Apr 2011 20:51:12 -0400 Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay03.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p3N11sfK081168 for ; Fri, 22 Apr 2011 21:01:54 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p3ML1gxh025171 for ; Fri, 22 Apr 2011 18:01:42 -0300 In-Reply-To: <1303520502-32171-1-git-send-email-john.stultz@linaro.org> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: linux-mmc@vger.kernel.org Cc: San Mehat , Chris Ball , Arnd Bergmann , Dima Zavin , John Stultz From: San Mehat CC: Chris Ball CC: Arnd Bergmann CC: Dima Zavin Signed-off-by: San Mehat [Add depends on EXPERIMENTAL -jstultz] Signed-off-by: John Stultz --- drivers/mmc/core/Kconfig | 9 +++++++++ drivers/mmc/core/sd.c | 22 ++++++++++++++++++++++ 2 files changed, 31 insertions(+), 0 deletions(-) diff --git a/drivers/mmc/core/Kconfig b/drivers/mmc/core/Kconfig index ef10387..ffc671e 100644 --- a/drivers/mmc/core/Kconfig +++ b/drivers/mmc/core/Kconfig @@ -27,3 +27,12 @@ config MMC_CLKGATE support handling this in order for it to be of any use. If unsure, say N. + +config MMC_PARANOID_SD_INIT + bool "Enable paranoid SD card initialization (EXPERIMENTAL)" + depends on EXPERIMENTAL + help + If you say Y here, the MMC layer will be extra paranoid + about re-trying SD init requests. This can be a useful + work-around for buggy controllers and hardware. Enable + if you are experiencing issues with SD detection. diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index 6dac89f..c0f14cb 100644 --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -403,6 +403,9 @@ struct device_type sd_type = { int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid) { int err; +#ifdef CONFIG_MMC_PARANOID_SD_INIT + int retries; +#endif /* * Since we're changing the OCR value, we seem to @@ -482,7 +485,26 @@ int mmc_sd_setup_card(struct mmc_host *host, struct mmc_card *card, /* * Fetch switch information from card. */ +#ifdef CONFIG_MMC_PARANOID_SD_INIT + for (retries = 1; retries <= 3; retries++) { + err = mmc_read_switch(card); + if (!err) { + if (retries > 1) { + printk(KERN_WARNING + "%s: recovered\n", + mmc_hostname(host)); + } + break; + } else { + printk(KERN_WARNING + "%s: read switch failed (attempt %d)\n", + mmc_hostname(host), retries); + } + } +#else err = mmc_read_switch(card); +#endif + if (err) return err; } -- 1.7.3.2.146.gca209