1 files changed, 40 insertions, 0 deletions

diff --git a/recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.17/0097-dmaengine-at_hdmac-remove-clear-on-read-in-atc_dosta.patch b/recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.17/0097-dmaengine-at_hdmac-remove-clear-on-read-in-atc_dosta.patch
new file mode 100644
index 00000000..b670af28
--- /dev/null
+++ b/recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.17/0097-dmaengine-at_hdmac-remove-clear-on-read-in-atc_dosta.patch
@@ -0,0 +1,40 @@
+From 461507ae293668a6dd1543092d2506fa4524d8ec Mon Sep 17 00:00:00 2001
+From: Nicolas Ferre <nicolas.ferre@atmel.com>
+Date: Mon, 16 Apr 2012 14:46:30 +0200
+Subject: [PATCH 097/165] dmaengine: at_hdmac: remove clear-on-read in
+ atc_dostart()
+
+commit ed8b0d67f33518a16c6b2450fe5ebebf180c2d04 upstream.
+
+This loop on EBCISR register was designed to clear IRQ sources before enabling
+a DMA channel. This register is clear-on-read so a race condition can appear if
+another channel is already active and has just finished its transfer.
+Removing this read on EBCISR is fixing the issue as there is no case where an IRQ
+could be pending: we already make sure that this register is drained at probe()
+time and during resume.
+
+Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
+Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
+Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
+---
+ drivers/dma/at_hdmac.c |    4 ----
+ 1 files changed, 0 insertions(+), 4 deletions(-)
+
+diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
+index a60adbf..79dcf6e 100644
+--- a/drivers/dma/at_hdmac.c
++++ b/drivers/dma/at_hdmac.c
+@@ -239,10 +239,6 @@ static void atc_dostart(struct at_dma_chan *atchan, struct at_desc *first)
+ 
+        vdbg_dump_regs(atchan);
+ 
+-       /* clear any pending interrupt */
+-       while (dma_readl(atdma, EBCISR))
+-               cpu_relax();
+-
+        channel_writel(atchan, SADDR, 0);
+        channel_writel(atchan, DADDR, 0);
+        channel_writel(atchan, CTRLA, 0);
+-- 
+1.7.7.6
+