Thread (4 messages) 4 messages, 3 authors, 2010-08-27
DORMANTno replies

[PATCH 01/03] omap hsmmc: prevent race between dma and hsmmc callback

From: Chris Ball <hidden>
Date: 2010-08-27 19:37:27
Also in: linux-mmc, linux-omap

Hi,

Looks like the discussion on this patch stopped: do we think there's a
race worth fixing here?

On Wed, Mar 10, 2010 at 07:41:38PM +0530, Venkatraman S wrote:
quoted hunk ↗ jump to hunk
See previous post http://patchwork.kernel.org/patch/82907/
Rebased to 2.6.34-rc1 and fixed comment alignment.

CC: Adrian Hunter <redacted>
CC: Madhusudhan C <redacted>
CC: Tony Lindgren <tony@atomide.com>
Signed-off-by: Venkatraman S <redacted>
---
 drivers/mmc/host/omap_hsmmc.c |   19 +++++++++++--------
 1 files changed, 11 insertions(+), 8 deletions(-)
diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 83f0aff..ea2a082 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -1046,8 +1046,18 @@ static irqreturn_t omap_hsmmc_irq(int irq, void *dev_id)

 	if (end_cmd || ((status & CC) && host->cmd))
 		omap_hsmmc_cmd_done(host, host->cmd);
-	if ((end_trans || (status & TC)) && host->mrq)
+	if ((end_trans || (status & TC)) && host->mrq) {
 		omap_hsmmc_xfer_done(host, data);
+		if (host->dma_ch != -1) {
+			omap_free_dma(host->dma_ch);
+			host->dma_ch = -1;
+			/*
+			 * Callback: run in interrupt context.
+			 * mutex_unlock will throw a kernel warning if used.
+			 */
+			up(&host->sem);
+		}
+	}

 	spin_unlock(&host->irq_lock);
@@ -1267,13 +1277,6 @@ static void omap_hsmmc_dma_cb(int lch, u16
ch_status, void *data)
 		return;
 	}

-	omap_free_dma(host->dma_ch);
-	host->dma_ch = -1;
-	/*
-	 * DMA Callback: run in interrupt context.
-	 * mutex_unlock will throw a kernel warning if used.
-	 */
-	up(&host->sem);
 }

 /*
-- 
1.6.3.3
-- 
Chris Ball   [off-list ref]   <http://printf.net/>
One Laptop Per Child
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