[3.19.y-ckt stable] Patch "mmc: sdhci: Fix override of timeout clk wrt max_busy_timeout" has been added to the 3.19.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    mmc: sdhci: Fix override of timeout clk wrt max_busy_timeout

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt18.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From f651bb56effa2c09236969d642f7f6890b21bece Mon Sep 17 00:00:00 2001
From: Adrian Hunter <adrian.hunter at intel.com>
Date: Mon, 7 Mar 2016 13:33:55 +0200
Subject: mmc: sdhci: Fix override of timeout clk wrt max_busy_timeout

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.

Signed-off-by: Adrian Hunter <adrian.hunter at intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson at linaro.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/mmc/host/sdhci.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index f68de85..17d79d8 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -3080,14 +3080,14 @@ int sdhci_add_host(struct sdhci_host *host)
 		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;

--
2.7.4