diff options
| author | Damien Lespiau <damien.lespiau@intel.com> | 2013-10-15 18:55:40 +0100 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2013-10-16 13:32:16 +0200 |
| commit | 071444280bcbb96ec38a1fb1ee3924ca7860844a (patch) | |
| tree | 49171943b164c5f1c00fc3418e43500834e9e681 /drivers/gpu/drm/i915/i915_drv.h | |
| parent | 497666d80587933fc65dbe40d8fe6b6cc89ac9ad (diff) | |
| download | lwn-071444280bcbb96ec38a1fb1ee3924ca7860844a.tar.gz lwn-071444280bcbb96ec38a1fb1ee3924ca7860844a.zip | |
drm/i915: Implement blocking read for pipe CRC files
seq_file is not quite the right interface for these ones. We have a
circular buffer with a new entry per vblank on one side and a process
wanting to dequeue the CRC with a read().
It's quite racy to wait for vblank in user land and then try to read a
pipe_crc file, sometimes the CRC interrupt hasn't been fired and we end
up with an EOF.
So, let's have the read on the pipe_crc file block until the interrupt
gives us a new entry. At that point we can wake the reading process.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm/i915/i915_drv.h')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_drv.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 1faeaac5f9f3..7408f1184347 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1235,6 +1235,7 @@ struct intel_pipe_crc { struct intel_pipe_crc_entry *entries; enum intel_pipe_crc_source source; atomic_t head, tail; + wait_queue_head_t wq; }; typedef struct drm_i915_private { @@ -2233,6 +2234,11 @@ int i915_verify_lists(struct drm_device *dev); /* i915_debugfs.c */ int i915_debugfs_init(struct drm_minor *minor); void i915_debugfs_cleanup(struct drm_minor *minor); +#if defined(CONFIG_DEBUG_FS) +void intel_display_crc_init(struct drm_device *dev); +#else +void intel_display_crc_init(struct drm_device *dev) {} +#endif /* i915_gpu_error.c */ __printf(2, 3) |