From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: "treul" <lgijnpuhx@gmail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: dma hardware underrun
Date: Sun, 22 Jul 2007 15:53:10 +0100 [thread overview]
Message-ID: <20070722155310.47f98ca4@the-village.bc.nu> (raw)
In-Reply-To: <f7vnsh$aun$1@sea.gmane.org>
> My debugging result shows the underrun goes away if I put 2 printf's in the
> harddisk ISR. The printf is at milli-seconds whereas the duration of the
> original ISR is at lower magnitude. In addition, I find a SATA-PCI harddisk
> does not have the underrun problem. IDE-PCI device gets the trouble.
Is the SATA controller on the motherboard and the PATA one on the PCI
bus ?
> So, do you have any idea about where the root cause can be hiding? Or what
> do you think of adding printf's in ISR? (performance? incurring other
> problems by disabling interrupt too long?
On a standard PCI bus an IDE DMA disk can saturate the bus. That may be
your underlying problem ?
prev parent reply other threads:[~2007-07-22 14:46 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-07-22 13:59 dma hardware underrun treul
2007-07-22 14:53 ` Alan Cox [this message]
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