Messages in this thread | | | Subject | RE: [PATCH 5/5] Add DMA engine driver for Freescale MPC85xx processors. | Date | Tue, 11 Sep 2007 08:15:30 -0700 | From | "Nelson, Shannon" <> |
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>From: Scott Wood [mailto:scottwood@freescale.com] >Sent: Tuesday, September 11, 2007 7:20 AM >To: Zhang Wei-r63237 >Cc: Nelson, Shannon; paulus@samba.org; >linuxppc-dev@ozlabs.org; Williams, Dan J; linux-kernel@vger.kernel.org >Subject: Re: [PATCH 5/5] Add DMA engine driver for Freescale >MPC85xx processors. > >On Tue, Sep 11, 2007 at 06:10:53PM +0800, Zhang Wei-r63237 wrote: >> > >+ >> > >+ fsl_dma_memcpy_issue_pending(chan); >> > >+ while (fsl_dma_is_complete(chan, cookie, NULL, NULL) >> > >+ != DMA_SUCCESS); >> > >> > Again, is it possible to hang your thread here? >> > >> > [...] >> >> 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.
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