From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH 4/6] mmc: sd: Add new CONFIG_MMC_PARANOID_SD_INIT for enabling retries during SD detection Date: Tue, 26 Apr 2011 15:35:52 +0200 Message-ID: <201104261535.52521.arnd@arndb.de> References: <1303520502-32171-1-git-send-email-john.stultz@linaro.org> <1303520502-32171-5-git-send-email-john.stultz@linaro.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Return-path: Received: from moutng.kundenserver.de ([212.227.17.10]:62844 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754361Ab1DZNgR (ORCPT ); Tue, 26 Apr 2011 09:36:17 -0400 In-Reply-To: <1303520502-32171-5-git-send-email-john.stultz@linaro.org> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: John Stultz Cc: linux-mmc@vger.kernel.org, San Mehat , Chris Ball , Dima Zavin On Saturday 23 April 2011, John Stultz wrote: > @@ -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 > + I see no reason to have this as a compile time option. Having retries in here might be useful, but a better place would be inside of mmc_read_switch() or mmc_sd_switch() so it is only done if the error comes from the controller, not for cases where we know it will fail (e.g. !(card->csd.cmdclass & CCC_SWITCH)). I would also recommend being a bit less noisy, e.g. print a warning only after either giving up or succeeding a retry. Arnd