On Tuesday 16 July 2013 03:57 PM, Grygorii Strashko wrote:
> Hi Rajendra,
>
> On 07/11/2013 12:17 PM, Rajendra Nayak wrote:
>> On Wednesday 10 July 2013 09:37 PM, Felipe Balbi wrote:
>>> how about something like below ? It makes omap_device/hwmod and
>>> pm_runtime agree on the initial state of the device and will prevent
>>> ->runtime_resume() from being called on first pm_runtime_get*() done
>>> during probe.
>>>
>>> This is similar to what PCI bus does (if you look at pci_pm_init()).
>>
>> I tried something similar [1] but what I found is that the serial
>> runtime resume was called despite it being marked as active using
>> pm_runtime_set_active().
>>
>> That seems to be because of the pm_runtime_set_autosuspend_delay()
>> because we have the autosuspend_delay = -1
>>
>> -----
>> static void update_autosuspend(struct device *dev, int old_delay, int
>> old_use)
>> {
>> int delay = dev->power.autosuspend_delay;
>>
>> /* Should runtime suspend be prevented now? */
>> if (dev->power.use_autosuspend && delay < 0) {
>>
>> /* If it used to be allowed then prevent it. */
>> if (!old_use || old_delay >= 0) {
>> atomic_inc(&dev->power.usage_count);
>> rpm_resume(dev, 0);
>> <------------------------------- calls serial runtime resume.
>> }
>> }
>> -----
>>
>> So we end up with the same issue with serial resume being called before
>> set_termios()
>>
>> [1]
>>
>> diff --git a/arch/arm/mach-omap2/omap_device.c
>> b/arch/arm/mach-omap2/omap_device.c
>> index 5cc9287..c71d47d 100644
>> --- a/arch/arm/mach-omap2/omap_device.c
>> +++ b/arch/arm/mach-omap2/omap_device.c
>> @@ -129,6 +129,7 @@ static int omap_device_build_from_dt(struct
>> platform_device *pdev)
>> struct device_node *node = pdev->dev.of_node;
>> const char *oh_name;
>> int oh_cnt, i, ret = 0;
>> + bool device_active = false;
>>
>> oh_cnt = of_property_count_strings(node, "ti,hwmods");
>> if (oh_cnt <= 0) {
>> @@ -152,6 +153,9 @@ static int omap_device_build_from_dt(struct
>> platform_device *pdev)
>> goto odbfd_exit1;
>> }
>> hwmods[i] = oh;
>> + if (oh->flags & HWMOD_INIT_NO_IDLE)
>> + device_active = true;
>> +
>> }
>>
>> od = omap_device_alloc(pdev, hwmods, oh_cnt);
>> @@ -172,6 +176,11 @@ static int omap_device_build_from_dt(struct
>> platform_device *pdev)
>>
>> pdev->dev.pm_domain = &omap_device_pm_domain;
>>
>> + if (device_active) {
>> + omap_device_enable(pdev);
>> + pm_runtime_set_active(&pdev->dev);
>> + }
>> +
>> odbfd_exit1:
>> kfree(hwmods);
>> odbfd_exit:
>
> This solution works good for me in combination with
> "serial: omap: enable PM runtime only when its fully configured"
> http://www.spinics.net/lists/linux-serial/msg10317.html
> (earlyprintk use case)
>
> And I think the best way would be to move forward with yours solution.
> - it will affect only on needed IPs drivers - not on all, so no issues with
> iommu and etc.
Ok, good to know that this solution works. Anyone has any other thoughts on
whats the best
way to fix this for the -rcs? (Note that we have bootup broken on all OMAPs
with DEBUG_LL
for now, atleast for all DT only platforms)
The other option of course is to use the patch posted by Felipe [1], thought
that had issues
handling processor IPs as pointed out by Grygorii and Suman [2], the fix I
posted [3] to make
omap_device aware of hwmod bypassing these IPs might fix some of those, but
this solution in
general would need more testing as it affects all modules on the bus.
[1] http://www.spinics.net/lists/arm-kernel/msg258062.html
[2] http://www.spinics.net/lists/arm-kernel/msg258061.html
[3] http://www.spinics.net/lists/arm-kernel/msg258465.html
>
> But issue with *non console" UARTs will still be here and, I think,
> there are no way ti solve it from OMAP device/hwmod frameworks side,
> because only driver can know when his context is ready.
> To test do: #echo 0xDEAD > dev/ttyO3
>
> Regards,
> -grygorii
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