From: Daniel Walker <dwalker@codeaurora.org>
To: Sahitya Tummala <stummala@codeaurora.org>
Cc: cjb@laptop.org, linux-mmc@vger.kernel.org, san@google.com,
linux-arm-msm@vger.kernel.org
Subject: Re: [PATCH V2 1/5] mmc: msm_sdcc: Fix possible circular locking dependency warning
Date: Wed, 08 Dec 2010 10:25:26 -0800 [thread overview]
Message-ID: <1291832726.12568.5.camel@c-dwalke-linux.qualcomm.com> (raw)
In-Reply-To: <1291800787-24757-1-git-send-email-stummala@codeaurora.org>
On Wed, 2010-12-08 at 15:03 +0530, Sahitya Tummala wrote:
> In the context of request processing thread, data mover lock is
> acquired after the host lock. In another context, in the completion
> handler of data mover the locks are acquired in the reverse order,
> resulting in possible circular lock dependency warning. Hence,
> schedule a tasklet to process the dma completion so as to avoid
> nested locks.
>
Can you just alter the location where the locks are taken ?
This lock,
spin_lock_irqsave(&host->lock, flags);
seems not fine grained at all .. That lock is just being held over very
large sections of code which it doesn't seems like it needs to be. It
doesn't appear to be protecting just the data structures.
Daniel
--
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
next prev parent reply other threads:[~2010-12-08 18:25 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-08 9:33 [PATCH V2 1/5] mmc: msm_sdcc: Fix possible circular locking dependency warning Sahitya Tummala
2010-12-08 9:33 ` [PATCH V2 2/5] mmc: msm_sdcc: Add prog done interrupt support Sahitya Tummala
2010-12-08 9:33 ` [PATCH V2 3/5] mmc: msm_sdcc: Reset SDCC in case of data transfer errors Sahitya Tummala
2010-12-08 9:33 ` [PATCH V2 4/5] mmc: msm_sdcc: Fix bug in PIO mode when data size is not word aligned Sahitya Tummala
2010-12-08 9:33 ` [PATCH V2 5/5] mmc: msm_sdcc: Check for only DATA_END interrupt to end a request Sahitya Tummala
2010-12-08 18:25 ` Daniel Walker [this message]
2010-12-09 15:21 ` [PATCH V2 1/5] mmc: msm_sdcc: Fix possible circular locking dependency warning Sahitya Tummala
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