From: Pierre Ossman <drzeus-mmc@drzeus.cx>
To: "Bryan Wu" <cooloney.lkml@gmail.com>
Cc: "Cai, Cliff" <Cliff.Cai@analog.com>,
"Mike Frysinger" <vapier.adi@gmail.com>,
linux-kernel@vger.kernel.org
Subject: Re: [patch] split MMC_CAP_4_BIT_DATA
Date: Fri, 11 Jan 2008 09:40:36 +0100 [thread overview]
Message-ID: <20080111094036.4c683791@poseidon.drzeus.cx> (raw)
In-Reply-To: <386072610801102217u1739d7d7v497e73a38aa876c2@mail.gmail.com>
On Fri, 11 Jan 2008 14:17:01 +0800
"Bryan Wu" <cooloney.lkml@gmail.com> wrote:
> We were told this is an hardware design issue, so please help us to
> workaround it in software side with Mike's patch.
I'm afraid that's insufficient motivation for this change. All documentation and real world tests say that MMC and SD 4-bit data is 100% compatible. So it's far more probable that you've misdiagnosed your error than this being the actual problem. The fact that 4-bit MMC support has been present for some time and you're only now seeing a problem further supports that.
In light of that, the suggested patch would not only be incorrect, it would also be worse than doing nothing. You would be papering over a symptom, making the real problem harder to find.
If you want something ready for upstream, for now I suggest removing MMC_CAP_4_BIT_DATA completely from your driver's caps field.
Rgds
--
-- Pierre Ossman
Linux kernel, MMC maintainer http://www.kernel.org
PulseAudio, core developer http://pulseaudio.org
rdesktop, core developer http://www.rdesktop.org
next prev parent reply other threads:[~2008-01-11 8:40 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-08 18:29 Mike Frysinger
2008-01-08 19:21 ` Pierre Ossman
2008-01-08 19:40 ` Mike Frysinger
2008-01-08 20:49 ` Pierre Ossman
2008-01-08 21:44 ` Mike Frysinger
2008-01-09 7:21 ` Pierre Ossman
2008-01-09 2:32 ` Bryan Wu
2008-01-09 3:21 ` Cai, Cliff
2008-01-09 7:23 ` Pierre Ossman
2008-01-09 16:45 ` Bryan Wu
2008-01-10 8:54 ` Pierre Ossman
2008-01-10 9:22 ` Bryan Wu
2008-01-10 11:57 ` Pierre Ossman
2008-01-11 6:17 ` Bryan Wu
2008-01-11 6:25 ` Mike Frysinger
2008-01-11 8:40 ` Pierre Ossman [this message]
2008-01-11 9:08 ` Mike Frysinger
2008-01-11 9:35 ` Pierre Ossman
2008-01-11 9:47 ` Mike Frysinger
2008-01-11 10:05 ` Pierre Ossman
2008-01-11 10:22 ` Bryan Wu
2008-01-11 11:18 ` Pierre Ossman
2008-01-11 17:52 ` Robin Getz
2008-01-12 13:02 ` Robin Getz
2008-01-12 15:24 ` Bryan Wu
2008-01-12 15:39 ` Pierre Ossman
2008-01-09 4:23 ` Bryan Wu
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