This is a note to let you know that I've just added the patch titled
mmc: sdio: fix alignment issue in struct sdio_func
to the 3.18-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-sdio-fix-alignment-issue-in-struct-sdio_func.patch
and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Thu Oct 5 10:58:04 CEST 2017
From: Heiner Kallweit <hkallweit1@xxxxxxxxx>
Date: Wed, 29 Mar 2017 20:54:37 +0200
Subject: mmc: sdio: fix alignment issue in struct sdio_func
From: Heiner Kallweit <hkallweit1@xxxxxxxxx>
[ Upstream commit 5ef1ecf060f28ecef313b5723f1fd39bf5a35f56 ]
Certain 64-bit systems (e.g. Amlogic Meson GX) require buffers to be
used for DMA to be 8-byte-aligned. struct sdio_func has an embedded
small DMA buffer not meeting this requirement.
When testing switching to descriptor chain mode in meson-gx driver
SDIO is broken therefore. Fix this by allocating the small DMA buffer
separately as kmalloc ensures that the returned memory area is
properly aligned for every basic data type.
Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
Tested-by: Helmut Klein <hgkr.klein@xxxxxxxxx>
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/mmc/core/sdio_bus.c | 12 +++++++++++-
include/linux/mmc/sdio_func.h | 2 +-
2 files changed, 12 insertions(+), 2 deletions(-)
--- a/drivers/mmc/core/sdio_bus.c
+++ b/drivers/mmc/core/sdio_bus.c
@@ -265,7 +265,7 @@ static void sdio_release_func(struct dev
sdio_free_func_cis(func);
kfree(func->info);
-
+ kfree(func->tmpbuf);
kfree(func);
}
@@ -280,6 +280,16 @@ struct sdio_func *sdio_alloc_func(struct
if (!func)
return ERR_PTR(-ENOMEM);
+ /*
+ * allocate buffer separately to make sure it's properly aligned for
+ * DMA usage (incl. 64 bit DMA)
+ */
+ func->tmpbuf = kmalloc(4, GFP_KERNEL);
+ if (!func->tmpbuf) {
+ kfree(func);
+ return ERR_PTR(-ENOMEM);
+ }
+
func->card = card;
device_initialize(&func->dev);
--- a/include/linux/mmc/sdio_func.h
+++ b/include/linux/mmc/sdio_func.h
@@ -53,7 +53,7 @@ struct sdio_func {
unsigned int state; /* function state */
#define SDIO_STATE_PRESENT (1<<0) /* present in sysfs */
- u8 tmpbuf[4]; /* DMA:able scratch buffer */
+ u8 *tmpbuf; /* DMA:able scratch buffer */
unsigned num_info; /* number of info strings */
const char **info; /* info strings */
Patches currently in stable-queue which might be from hkallweit1@xxxxxxxxx are
queue-3.18/mmc-sdio-fix-alignment-issue-in-struct-sdio_func.patch