From: Ben Dooks <ben-linux@fluff.org>
To: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Ben Dooks <ben-linux@fluff.org>,
linux-kernel@vger.kernel.org, drzeus-mmc@drzeus.cx,
sdhci-devel@list.drzeus.cx
Subject: Re: [patch 6/7] SDHCI: Check DMA for overruns at end of transfer
Date: Mon, 3 Nov 2008 21:16:25 +0000 [thread overview]
Message-ID: <20081103211625.GG14806@trinity.fluff.org> (raw)
In-Reply-To: <20081103211200.GA10721@khazad-dum.debian.net>
On Mon, Nov 03, 2008 at 07:12:00PM -0200, Henrique de Moraes Holschuh wrote:
> Maybe I didn't understand it right, but if the DMA controller could overrun
> a buffer, don't you ALSO need to add defensive padding (i.e. increase the
> buffer) to make sure nothing important gets overrun?
This is only generated by problems elsewhere in the driver, such as
getting the timeout clock wrong. It is here just as a precaution and
as an aide to debugging, it should not trigger in normal circumstances.
There is a seperate problem where the DMA buffer is passed from the stack
which is, IIRC, a complete no-no under Linux.
--
Ben
Q: What's a light-year?
A: One-third less calories than a regular year.
next prev parent reply other threads:[~2008-11-03 21:16 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-03 20:09 [patch 0/7] SDHCI support for Samsung SoC Ben Dooks
2008-11-03 20:09 ` [patch 1/7] SDHCI: Add timeout hooks Ben Dooks
2008-11-14 21:29 ` Pierre Ossman
2008-11-03 20:09 ` [patch 2/7] SDHCI: Print ADMA status and pointer on debug Ben Dooks
2008-11-14 21:29 ` Pierre Ossman
2008-11-03 20:09 ` [patch 3/7] SDHCI: Add set_ios hook Ben Dooks
2008-11-14 21:32 ` Pierre Ossman
2008-11-03 20:09 ` [patch 4/7] SDHCI: Add quirk for controller with no end-of-busy IRQ Ben Dooks
2008-11-14 21:41 ` Pierre Ossman
2008-11-15 23:58 ` Ben Dooks
2008-11-03 20:09 ` [patch 5/7] SDHCI: Samsung SDHCI (HSMMC) driver Ben Dooks
2008-11-14 21:48 ` Pierre Ossman
2008-11-16 0:03 ` Ben Dooks
2008-11-19 18:38 ` Pierre Ossman
2008-11-03 20:09 ` [patch 6/7] SDHCI: Check DMA for overruns at end of transfer Ben Dooks
2008-11-03 21:12 ` Henrique de Moraes Holschuh
2008-11-03 21:16 ` Ben Dooks [this message]
2008-11-04 1:28 ` Henrique de Moraes Holschuh
2008-11-10 9:58 ` Ben Dooks
2008-11-14 22:00 ` Pierre Ossman
2008-11-16 0:05 ` Ben Dooks
2008-11-19 18:41 ` Pierre Ossman
2008-11-03 20:09 ` [patch 7/7] SDHCI: Add change_clock callback for glue drivers Ben Dooks
2008-11-14 22:20 ` Pierre Ossman
2008-11-15 23:57 ` Ben Dooks
2008-11-19 18:43 ` Pierre Ossman
2008-11-10 10:57 ` [patch 0/7] SDHCI support for Samsung SoC Ben Dooks
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