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From: Tony Lindgren <tony@atomide.com>
To: linux-arm-kernel@lists.arm.linux.org.uk
Cc: Juha Yrjola <juha.yrjola@solidboot.com>, linux-omap@vger.kernel.org
Subject: [PATCH 3/9] ARM: OMAP: Fix race in OMAP2/3 DMA IRQ handling
Date: Wed, 28 Jan 2009 10:25:40 -0800	[thread overview]
Message-ID: <20090128182540.21007.97833.stgit@localhost> (raw)
In-Reply-To: <20090128181931.21007.73744.stgit@localhost>

From: Juha Yrjola <juha.yrjola@solidboot.com>

CSR must be cleared before invoking the callback.

If the callback function starts a new, fast DMA transfer on the same
channel, the completion status might lost if CSR is cleared after
the callback invocation.

Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/plat-omap/dma.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
index e77373c..bec8e36 100644
--- a/arch/arm/plat-omap/dma.c
+++ b/arch/arm/plat-omap/dma.c
@@ -1888,11 +1888,11 @@ static int omap2_dma_handle_ch(int ch)
 		status = dma_read(CSR(ch));
 	}
 
+	dma_write(status, CSR(ch));
+
 	if (likely(dma_chan[ch].callback != NULL))
 		dma_chan[ch].callback(ch, status, dma_chan[ch].data);
 
-	dma_write(status, CSR(ch));
-
 	return 0;
 }
 


  parent reply	other threads:[~2009-01-28 18:25 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-01-28 18:21 [PATCH 0/9] Omap fixes for 2.6.29-rc series, also one arm generic fix Tony Lindgren
2009-01-28 18:23 ` [PATCH 1/9] ARM: Do early I/O mapping if spinlock debugging is enabled Tony Lindgren
2009-01-28 18:53   ` Russell King - ARM Linux
2009-01-28 23:51     ` David Brownell
2009-01-29 16:52       ` Tony Lindgren
2009-01-28 18:24 ` [PATCH 2/9] ARM: OMAP: Fix McBSP spin_lock deadlock Tony Lindgren
2009-01-28 19:27   ` Russell King - ARM Linux
2009-01-28 21:28     ` Tony Lindgren
2009-01-28 23:53       ` David Brownell
2009-01-29  0:51         ` Tony Lindgren
2009-01-29  2:05           ` David Brownell
2009-01-28 18:25 ` Tony Lindgren [this message]
2009-01-28 18:26 ` [PATCH 4/9] ARM: OMAP: DMA: Fix uninitialized channel flags Tony Lindgren
2009-01-28 18:28 ` [PATCH 5/9] ARM: OMAP: Fix omap34xx revision detection for ES3.1 Tony Lindgren
2009-01-28 18:29 ` [PATCH 6/9] ARM: OMAP: Fix hsmmc init Tony Lindgren
2009-01-28 19:08   ` Russell King - ARM Linux
2009-01-29 18:48     ` [PATCH 6/9] ARM: OMAP: Fix hsmmc init, v2 Tony Lindgren
2009-01-28 18:30 ` [PATCH 7/9] ARM: OMAP: gptimer min_delta_ns corrected Tony Lindgren
2009-01-28 18:32 ` [PATCH 8/9] ARM: OMAP: Mask interrupts when disabling interrupts Tony Lindgren
2009-01-28 18:58   ` Russell King - ARM Linux
2009-01-28 19:07     ` [PATCH 8/9] ARM: OMAP: Mask interrupts when disabling interrupts, v2 Tony Lindgren
2009-01-28 18:33 ` [PATCH 9/9] ARM: OMAP: fix fault in enter_full_retention() Tony Lindgren
2009-01-28 19:21 ` [PATCH 0/9] Omap fixes for 2.6.29-rc series, also one arm generic fix Russell King - ARM Linux
2009-01-29 18:49   ` git pull request for omap-fixes (Re: [PATCH 0/9] Omap fixes for 2.6.29-rc series, also one arm generic fix) Tony Lindgren

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