Patch "mmc: sdhci: Fix override of timeout clk wrt max_busy_timeout" has been added to the 4.5-stable tree

This is a note to let you know that I've just added the patch titled

mmc: sdhci: Fix override of timeout clk wrt max_busy_timeout

to the 4.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
mmc-sdhci-fix-override-of-timeout-clk-wrt-max_busy_timeout.patch
and it can be found in the queue-4.5 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Adrian Hunter <[email protected]>
Date: Mon, 7 Mar 2016 13:33:55 +0200
Subject: mmc: sdhci: Fix override of timeout clk wrt max_busy_timeout

From: Adrian Hunter <[email protected]>

commit 995136247915c5cee633d55ba23f6eebf67aa567 upstream.

Normally the timeout clock frequency is read from the capabilities register. It is also possible to set the value prior to calling sdhci_add_host() in which case that value will override the capabilities register value. However that was being done after calculating max_busy_timeout so that max_busy_timeout was being calculated using the wrong value of timeout_clk.

Fix that by moving the override before max_busy_timeout is calculated.

The result is that the max_busy_timeout and max_discard increase for BSW devices so that, for example, the time for mkfs.ext4 on a 64GB eMMC drops from about 1 minute 40 seconds to about 20 seconds.

Note, in the future, the capabilities setting will be tidied up and this override won't be used anymore. However this fix is needed for stable.

---
 drivers/mmc/host/sdhci.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

@@ -3096,14 +3096,14 @@ int sdhci_add_host(struct sdhci_host *ho
 		if (caps[0] & SDHCI_TIMEOUT_CLK_UNIT)
 			host->timeout_clk *= 1000;
 
+		if (override_timeout_clk)
+			host->timeout_clk = override_timeout_clk;
+
 		mmc->max_busy_timeout = host->ops->get_max_timeout_count ?
 			host->ops->get_max_timeout_count(host) : 1 << 27;
 		mmc->max_busy_timeout /= host->timeout_clk;
 	}
 
-	if (override_timeout_clk)
-		host->timeout_clk = override_timeout_clk;
-
 	mmc->caps |= MMC_CAP_SDIO_IRQ | MMC_CAP_ERASE | MMC_CAP_CMD23;
 	mmc->caps2 |= MMC_CAP2_SDIO_IRQ_NOTHREAD;
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.5/mmc-sdhci-fix-command-response-crc-error-handling.patch queue-4.5/mmc-sdhci-avoid-unnecessary-mapping-unmapping-of-align-buffer.patch queue-4.5/perf-tools-fix-checking-asprintf-return-value.patch queue-4.5/mmc-sdhci-move-initialisation-of-command-error-member.patch queue-4.5/mmc-tegra-properly-disable-card-clock.patch queue-4.5/mmc-tegra-disable-uhs-i-modes-for-tegra114.patch queue-4.5/mmc-sdhci-fix-override-of-timeout-clk-wrt-max_busy_timeout.patch queue-4.5/mmc-sdhci-fix-data-timeout-part-2.patch queue-4.5/perf-x86-intel-add-definition-for-pt-pmi-bit.patch queue-4.5/mmc-sdhci-clean-up-command-error-handling.patch queue-4.5/mmc-sdhci-further-fix-for-dma-unmapping-in-sdhci_post_req.patch queue-4.5/mmc-sdhci-pxav3-fix-higher-speed-mode-capabilities.patch queue-4.5/mmc-sdhci-fix-data-timeout-part-1.patch queue-4.5/mmc-sdhci-plug-dma-mapping-leak-on-error.patch