Re: [PATCH v4 8/8] DMA: Freescale: add suspend resume functions for DMA driver

From: Hongbo Zhang
Date: Sun May 04 2014 - 06:22:48 EST



On 05/03/2014 12:46 AM, Vinod Koul wrote:
On Fri, Apr 18, 2014 at 04:17:51PM +0800, hongbo.zhang@xxxxxxxxxxxxx wrote:
From: Hongbo Zhang <hongbo.zhang@xxxxxxxxxxxxx>

This patch adds suspend resume functions for Freescale DMA driver.
.prepare callback is used to stop further descriptors from being added into the
pending queue, and also issue pending queues into execution if there is any.
.suspend callback makes sure all the pending jobs are cleaned up and all the
channels are idle, and save the mode registers.
.resume callback re-initializes the channels by restore the mode registers.

+
+static const struct dev_pm_ops fsldma_pm_ops = {
+ .prepare = fsldma_prepare,
+ .suspend = fsldma_suspend,
+ .resume = fsldma_resume,
+};
I think this is not correct. We discussed this sometime back on list. The
DMAengine drivers should use late resume and early suspend to ensure they get
suspended after clients (who should use normal ones) and resume before them

OK, will update it like this:
use .suspend to take place of current .prepare
use .suspend_late to take place of current .suspend
use .resume_early to take place of current .resume



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