From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: [PATCH] mmc: sdio: fix alignment issue in struct sdio_func Date: Wed, 29 Mar 2017 13:17:32 -0700 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from mail-pg0-f44.google.com ([74.125.83.44]:33116 "EHLO mail-pg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932763AbdC2URf (ORCPT ); Wed, 29 Mar 2017 16:17:35 -0400 Received: by mail-pg0-f44.google.com with SMTP id x125so17424023pgb.0 for ; Wed, 29 Mar 2017 13:17:34 -0700 (PDT) In-Reply-To: (Heiner Kallweit's message of "Wed, 29 Mar 2017 20:54:37 +0200") Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Heiner Kallweit Cc: Ulf Hansson , linux-amlogic@lists.infradead.org, Helmut Klein , "linux-mmc@vger.kernel.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