RE: [PATCH 5/5] Add DMA engine driver for Freescale MPC85xx processors.

From: Scott Wood [mailto:scottwood@freescale.com]=20
Sent: Tuesday, September 11, 2007 7:20 AM
To: Zhang Wei-r63237
Cc: Nelson, Shannon; paulus@samba.org;=20
linuxppc-dev@ozlabs.org; Williams, Dan J; linux-kernel@vger.kernel.org
Subject: Re: [PATCH 5/5] Add DMA engine driver for Freescale=20
MPC85xx processors.

On Tue, Sep 11, 2007 at 06:10:53PM +0800, Zhang Wei-r63237 wrote:

quoted

quoted

quoted

+
+	fsl_dma_memcpy_issue_pending(chan);
+	while (fsl_dma_is_complete(chan, cookie, NULL, NULL)
+			!=3D DMA_SUCCESS);

=20
Again, is it possible to hang your thread here?
=20
[...]

=20
I'll add msleep here.

I think what was being sought was a timout, causing the test to return
failure.

-Scott

Either a timeout to stop the polling, or msleep() followed by a single
call to fsl_dma_is_complete().  However, using the msleep() method is
likely to be kinder to the rest of the kernel than polling for very
long.

sln