From mboxrd@z Thu Jan 1 00:00:00 1970 From: khilman@baylibre.com (Kevin Hilman) Date: Wed, 29 Mar 2017 13:17:32 -0700 Subject: [PATCH] mmc: sdio: fix alignment issue in struct sdio_func In-Reply-To: (Heiner Kallweit's message of "Wed, 29 Mar 2017 20:54:37 +0200") References: Message-ID: To: linus-amlogic@lists.infradead.org List-Id: linus-amlogic.lists.infradead.org Heiner Kallweit writes: > 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 > Tested-by: Helmut Klein This should work too, without the need to do a tiny kmalloc. diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h index aab032a6ae61..071addf23931 100644 --- 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[4] __aligned(8); /* DMA:able scratch buffer */ unsigned num_info; /* number of info strings */ const char **info; /* info strings */ Kevin