On 7/26/19 2:08 PM, Andy Shevchenko wrote:
On Fri, Jul 26, 2019 at 01:08:57PM -0500, Pierre-Louis Bossart wrote:
This thread became unreadable with interleaved top-posting, allow me restate
the options and ask PM folks what they think
On 7/25/19 6:40 PM, Pierre-Louis Bossart wrote:
Not all platforms support runtime_pm for now, let's use runtime_pm
only when enabled.
Just a side note below...
- ret = pm_runtime_get_sync(slave->bus->dev);
- if (ret < 0)
Here...
- return ret;
+ if (pm_runtime_enabled(slave->bus->dev)) {
+ ret = pm_runtime_get_sync(slave->bus->dev);
+ if (ret < 0)
...and thus here...
+ return ret;
+ }
ret = sdw_transfer(slave->bus, &msg);
- pm_runtime_put(slave->bus->dev);
+
+ if (pm_runtime_enabled(slave->bus->dev))
+ pm_runtime_put(slave->bus->dev);
This is option1: we explicitly test if pm_runtime is enabled before calling
_get_sync() and _put()
option2 (suggested by Jan Kotas): catch the -EACCESS error code
ret = pm_runtime_get_sync(slave->bus->dev);
- if (ret < 0)
+ if (ret < 0 && ret != -EACCES)
...and here, the pm_runtime_put_noidle() call is missed.
yes but in the example you provided, they actually do more work than
just decrement the device usage counter:
static int
radeonfb_open(struct fb_info *info, int user)
{
struct radeon_fbdev *rfbdev = info->par;
struct radeon_device *rdev = rfbdev->rdev;
int ret = pm_runtime_get_sync(rdev->ddev->dev);
if (ret < 0 && ret != -EACCES) {
pm_runtime_mark_last_busy(rdev->ddev->dev);
pm_runtime_put_autosuspend(rdev->ddev->dev);
return ret;
}
return 0;
}
unless I am missing something pm_runtime_put_noidle() and
_put_autosuspend() are not equivalent, are they?
