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?