This is a note to let you know that I've just added the patch titled
mmc: atmel-mci: correct data timeout computation
to the 3.3-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-atmel-mci-correct-data-timeout-computation.patch
and it can be found in the queue-3.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 66292ad92c6d3f2f1c137a1c826b331ca8595dfd Mon Sep 17 00:00:00 2001
From: Ludovic Desroches <[email protected]>
Date: Wed, 28 Mar 2012 12:28:33 +0200
Subject: mmc: atmel-mci: correct data timeout computation
From: Ludovic Desroches <[email protected]>
commit 66292ad92c6d3f2f1c137a1c826b331ca8595dfd upstream.
The HSMCI operates at a rate of up to Master Clock divided by two.
Moreover previous calculation can cause overflows and so wrong
timeouts.
Signed-off-by: Ludovic Desroches <[email protected]>
Acked-by: Nicolas Ferre <[email protected]>
Signed-off-by: Chris Ball <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/mmc/host/atmel-mci.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -480,7 +480,14 @@ err:
static inline unsigned int atmci_ns_to_clocks(struct atmel_mci *host,
unsigned int ns)
{
- return (ns * (host->bus_hz / 1000000) + 999) / 1000;
+ /*
+ * It is easier here to use us instead of ns for the timeout,
+ * it prevents from overflows during calculation.
+ */
+ unsigned int us = DIV_ROUND_UP(ns, 1000);
+
+ /* Maximum clock frequency is host->bus_hz/2 */
+ return us * (DIV_ROUND_UP(host->bus_hz, 2000000));
}
static void atmci_set_timeout(struct atmel_mci *host,
Patches currently in stable-queue which might be from
[email protected] are
queue-3.3/mmc-atmel-mci-correct-data-timeout-computation.patch
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