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From: Heiner Kallweit <hkallweit1@gmail.com>
To: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
	linux-amlogic@lists.infradead.org,
	Helmut Klein <hgkr.klein@gmail.com>,
	Kevin Hilman <khilman@baylibre.com>
Subject: [PATCH v2] mmc: sdio: fix alignment issue in struct sdio_func
Date: Wed, 29 Mar 2017 22:56:50 +0200	[thread overview]
Message-ID: <3a6258f3-35e3-e2f5-aa6b-e509f603fa45@gmail.com> (raw)

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.
Testing an extension to meson-gx driver for switching to descriptor
chain mode broke SDIO therefore. Aligning tmpbuf to a 8-byte
boundary fixed the driver behavior.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Tested-by: Helmut Klein <hgkr.klein@gmail.com>
---
v2:
- switch to much simpler version as suggested by Kevin Hilman <khilman@baylibre.com>
- adjust commit message
---
 include/linux/mmc/sdio_func.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h
index aab032a6..65d90f76 100644
--- a/include/linux/mmc/sdio_func.h
+++ b/include/linux/mmc/sdio_func.h
@@ -53,7 +53,8 @@ struct sdio_func {
 	unsigned int		state;		/* function state */
 #define SDIO_STATE_PRESENT	(1<<0)		/* present in sysfs */
 
-	u8			tmpbuf[4];	/* DMA:able scratch buffer */
+	/* take care of proper alignment for DMA on certain 64-bit systems */
+	u8 __aligned(8)		tmpbuf[4];	/* DMA:able scratch buffer */
 
 	unsigned		num_info;	/* number of info strings */
 	const char		**info;		/* info strings */
-- 
2.12.1



WARNING: multiple messages have this Message-ID (diff)
From: hkallweit1@gmail.com (Heiner Kallweit)
To: linus-amlogic@lists.infradead.org
Subject: [PATCH v2] mmc: sdio: fix alignment issue in struct sdio_func
Date: Wed, 29 Mar 2017 22:56:50 +0200	[thread overview]
Message-ID: <3a6258f3-35e3-e2f5-aa6b-e509f603fa45@gmail.com> (raw)

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.
Testing an extension to meson-gx driver for switching to descriptor
chain mode broke SDIO therefore. Aligning tmpbuf to a 8-byte
boundary fixed the driver behavior.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Tested-by: Helmut Klein <hgkr.klein@gmail.com>
---
v2:
- switch to much simpler version as suggested by Kevin Hilman <khilman@baylibre.com>
- adjust commit message
---
 include/linux/mmc/sdio_func.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h
index aab032a6..65d90f76 100644
--- a/include/linux/mmc/sdio_func.h
+++ b/include/linux/mmc/sdio_func.h
@@ -53,7 +53,8 @@ struct sdio_func {
 	unsigned int		state;		/* function state */
 #define SDIO_STATE_PRESENT	(1<<0)		/* present in sysfs */
 
-	u8			tmpbuf[4];	/* DMA:able scratch buffer */
+	/* take care of proper alignment for DMA on certain 64-bit systems */
+	u8 __aligned(8)		tmpbuf[4];	/* DMA:able scratch buffer */
 
 	unsigned		num_info;	/* number of info strings */
 	const char		**info;		/* info strings */
-- 
2.12.1

             reply	other threads:[~2017-03-29 20:57 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-29 20:56 Heiner Kallweit [this message]
2017-03-29 20:56 ` [PATCH v2] mmc: sdio: fix alignment issue in struct sdio_func Heiner Kallweit
2017-03-29 22:58 ` Kevin Hilman
2017-03-29 22:58   ` Kevin Hilman
2017-04-13 20:54 ` Heiner Kallweit
2017-04-13 20:54   ` Heiner Kallweit

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