On Tuesday 26 August 2014 02:22 PM, Daniel Mack wrote:
> This patch makes the edma driver resume correctly after suspend. Tested
> on an AM33xx platform with cyclic audio streams and omap_hsmmc.
>
> All information can be reconstructed by already known runtime
> information.
>
> As we now use some functions that were previously only used from __init
> context, annotations had to be dropped.
>
> [nm@xxxxxx: added error handling for runtime + suspend_late/early_resume]
> Signed-off-by: Nishanth Menon <nm@xxxxxx>
> Signed-off-by: Daniel Mack <zonque@xxxxxxxxx>
> Tested-by: Joel Fernandes <joelf@xxxxxx>
> Acked-by: Joel Fernandes <joelf@xxxxxx>
> ---
> Changes from v8:
>
> * Drop the edma_suspend hook altogether. Even though back then
> when I wrote the code I was sure disabling the interrupts
> during suspend is necessary, tests now show it in fact isn't.
> My test setup still works if that code is omitted.
> * Use SET_LATE_SYSTEM_SLEEP_PM_OPS in the dev_pm_ops
> declaration.
>
> Thanks to Sekhar for pointing out the above.
>
> arch/arm/common/edma.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 58 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
> index 485be42..c623dd0 100644
> --- a/arch/arm/common/edma.c
> +++ b/arch/arm/common/edma.c
> @@ -244,6 +244,8 @@ struct edma {
> /* list of channels with no even trigger; terminated by "-1" */
> const s8 *noevent;
>
> + struct edma_soc_info *info;
> +
> /* The edma_inuse bit for each PaRAM slot is clear unless the
> * channel is in use ... by ARM or DSP, for QDMA, or whatever.
> */
> @@ -295,7 +297,7 @@ static void map_dmach_queue(unsigned ctlr, unsigned ch_no,
> ~(0x7 << bit), queue_no << bit);
> }
>
> -static void __init assign_priority_to_queue(unsigned ctlr, int queue_no,
> +static void assign_priority_to_queue(unsigned ctlr, int queue_no,
> int priority)
> {
> int bit = queue_no * 4;
> @@ -314,7 +316,7 @@ static void __init assign_priority_to_queue(unsigned ctlr, int queue_no,
> * included in that particular EDMA variant (Eg : dm646x)
> *
> */
> -static void __init map_dmach_param(unsigned ctlr)
> +static void map_dmach_param(unsigned ctlr)
> {
> int i;
> for (i = 0; i < EDMA_MAX_DMACH; i++)
> @@ -1762,15 +1764,69 @@ static int edma_probe(struct platform_device *pdev)
> edma_write_array2(j, EDMA_DRAE, i, 1, 0x0);
> edma_write_array(j, EDMA_QRAE, i, 0x0);
> }
> + edma_cc[j]->info = info[j];
> arch_num_cc++;
> }
>
> return 0;
> }
>
> +static int edma_pm_resume(struct device *dev)
> +{
> + int i, j, r;
> +
> + r = pm_runtime_get_sync(dev);
I think I have asked this before, and I am still not sure why this call
to pm_runtime_get_sync() is needed here. From my testing today, this
does seem to be a a no-op and this call returns from rpm_resume()
because of this check:
else if (dev->power.disable_depth == 1 && dev->power.is_suspended
&& dev->power.runtime_status == RPM_ACTIVE)
retval = 1;
So, AFAICS, the net effect is an increment of dev->power.usage_count
(which is already greater than 0) and its subsequent decrement at the
end of the function.
After removing this call I did not see any EDMA malfunction as well
(can access MMC/SD just fine after suspend/resume cycle).
So, any objections to merging this patch with the attached hunk
applied?
Thanks,
Sekhar
---8<---
diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
index 1f492d5be9c0..79de6a23047b 100644
--- a/arch/arm/common/edma.c
+++ b/arch/arm/common/edma.c
@@ -1803,13 +1803,7 @@ static int edma_probe(struct platform_device *pdev)
static int edma_pm_resume(struct device *dev)
{
- int i, j, r;
-
- r = pm_runtime_get_sync(dev);
- if (r < 0) {
- dev_err(dev, "%s: get_sync returned %d\n", __func__, r);
- return r;
- }
+ int i, j;
for (j = 0; j < arch_num_cc; j++) {
struct edma *cc = edma_cc[j];
@@ -1844,8 +1838,6 @@ static int edma_pm_resume(struct device *dev)
}
}
- pm_runtime_put_sync(dev);
-
return 0;
}
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