Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751771AbWIGM6q (ORCPT ); Thu, 7 Sep 2006 08:58:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751773AbWIGM6q (ORCPT ); Thu, 7 Sep 2006 08:58:46 -0400 Received: from caramon.arm.linux.org.uk ([217.147.92.249]:10761 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S1751771AbWIGM6p (ORCPT ); Thu, 7 Sep 2006 08:58:45 -0400 Date: Thu, 7 Sep 2006 13:58:40 +0100 From: Russell King To: Pierre Ossman Cc: Pierre Ossman , linux-kernel@vger.kernel.org Subject: Re: [MMC] Fix SD timeout calculation Message-ID: <20060907125840.GA6015@dyn-67.arm.linux.org.uk> Mail-Followup-To: Pierre Ossman , Pierre Ossman , linux-kernel@vger.kernel.org References: <20060618123432.15915.71389.stgit@poseidon.drzeus.cx> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060618123432.15915.71389.stgit@poseidon.drzeus.cx> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4820 Lines: 167 On Sun, Jun 18, 2006 at 02:34:37PM +0200, Pierre Ossman wrote: > Secure Digital cards use a different algorithm to calculate the timeout > for data transfers. Using the MMC one works often, but not always. Applied, thanks. I'm wondering about this cleanup though - both the timeout calculations appear to be identical, so making this a library function seems to be the right way to go... unless you know different? diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index c0c7ef2..74eaaee 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -247,6 +247,55 @@ int mmc_wait_for_app_cmd(struct mmc_host EXPORT_SYMBOL(mmc_wait_for_app_cmd); +/** + * mmc_set_data_timeout - set the timeout for a data command + * @data: data phase for command + * @card: the MMC card associated with the data transfer + * @write: flag to differentiate reads from writes + */ +void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card, + int write) +{ + unsigned int mult; + + /* + * SD cards use a 100 multiplier rather than 10 + */ + mult = mmc_card_sd(card) ? 100 : 10; + + /* + * Scale up the multiplier (and therefore the timeout) by + * the r2w factor for writes. + */ + if (write) + mult <<= card->csd.r2w_factor; + + data->timeout_ns = card->csd.tacc_ns * mult; + data->timeout_clks = card->csd.tacc_clks * mult; + + /* + * SD cards also have an upper limit on the timeout. + */ + if (mmc_card_sd(card)) { + unsigned int timeout_us, limit_us; + + timeout_us = data->timeout_ns / 1000; + timeout_us += data->timeout_clks * 1000 / + (card->host->ios.clock / 1000); + + if (write) + limit_us = 250000; + else + limit_us = 100000; + + if (timeout_us > limit_us) { + data->timeout_ns = limit_us * 1000; + data->timeout_clks = 0; + } + } +} +EXPORT_SYMBOL(mmc_set_data_timeout); + static int mmc_select_card(struct mmc_host *host, struct mmc_card *card); /** @@ -908,12 +957,9 @@ static void mmc_read_scrs(struct mmc_hos { int err; struct mmc_card *card; - struct mmc_request mrq; struct mmc_command cmd; struct mmc_data data; - unsigned int timeout_us; - struct scatterlist sg; list_for_each_entry(card, &host->cards, node) { @@ -948,17 +994,7 @@ static void mmc_read_scrs(struct mmc_hos memset(&data, 0, sizeof(struct mmc_data)); - data.timeout_ns = card->csd.tacc_ns * 100; - data.timeout_clks = card->csd.tacc_clks * 100; - - timeout_us = data.timeout_ns / 1000; - timeout_us += data.timeout_clks * 1000 / - (host->ios.clock / 1000); - - if (timeout_us > 100000) { - data.timeout_ns = 100000000; - data.timeout_clks = 0; - } + mmc_set_data_timeout(&data, card, 0); data.blksz_bits = 3; data.blksz = 1 << 3; diff --git a/drivers/mmc/mmc_block.c b/drivers/mmc/mmc_block.c index 515fb22..d6fcc46 100644 --- a/drivers/mmc/mmc_block.c +++ b/drivers/mmc/mmc_block.c @@ -179,40 +179,7 @@ static int mmc_blk_issue_rq(struct mmc_q brq.stop.arg = 0; brq.stop.flags = MMC_RSP_R1B | MMC_CMD_AC; - brq.data.timeout_ns = card->csd.tacc_ns * 10; - brq.data.timeout_clks = card->csd.tacc_clks * 10; - - /* - * Scale up the timeout by the r2w factor - */ - if (rq_data_dir(req) == WRITE) { - brq.data.timeout_ns <<= card->csd.r2w_factor; - brq.data.timeout_clks <<= card->csd.r2w_factor; - } - - /* - * SD cards use a 100 multiplier and has a upper limit - */ - if (mmc_card_sd(card)) { - unsigned int limit_us, timeout_us; - - brq.data.timeout_ns *= 10; - brq.data.timeout_clks *= 10; - - if (rq_data_dir(req) == READ) - limit_us = 100000; - else - limit_us = 250000; - - timeout_us = brq.data.timeout_ns / 1000; - timeout_us += brq.data.timeout_clks * 1000 / - (card->host->ios.clock / 1000); - - if (timeout_us > limit_us) { - brq.data.timeout_ns = limit_us * 1000; - brq.data.timeout_clks = 0; - } - } + mmc_set_data_timeout(&brq.data, card, rq_data_dir(req) != READ); if (rq_data_dir(req) == READ) { brq.cmd.opcode = brq.data.blocks > 1 ? MMC_READ_MULTIPLE_BLOCK : MMC_READ_SINGLE_BLOCK; diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h index 03a14a3..627e2c0 100644 --- a/include/linux/mmc/mmc.h +++ b/include/linux/mmc/mmc.h @@ -105,6 +105,8 @@ extern int mmc_wait_for_cmd(struct mmc_h extern int mmc_wait_for_app_cmd(struct mmc_host *, unsigned int, struct mmc_command *, int); +extern void mmc_set_data_timeout(struct mmc_data *, const struct mmc_card *, int); + extern int __mmc_claim_host(struct mmc_host *host, struct mmc_card *card); static inline void mmc_claim_host(struct mmc_host *host) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/