diff options
Diffstat (limited to 'drivers/gpu/drm/drm_debugfs_crc.c')
| -rw-r--r-- | drivers/gpu/drm/drm_debugfs_crc.c | 34 |
1 files changed, 26 insertions, 8 deletions
diff --git a/drivers/gpu/drm/drm_debugfs_crc.c b/drivers/gpu/drm/drm_debugfs_crc.c index 00e771fb7df2..96891c4a6e23 100644 --- a/drivers/gpu/drm/drm_debugfs_crc.c +++ b/drivers/gpu/drm/drm_debugfs_crc.c @@ -125,6 +125,12 @@ static const struct file_operations drm_crtc_crc_control_fops = { .write = crc_control_write }; +static int crtc_crc_data_count(struct drm_crtc_crc *crc) +{ + assert_spin_locked(&crc->lock); + return CIRC_CNT(crc->head, crc->tail, DRM_CRC_ENTRIES_NR); +} + static int crtc_crc_open(struct inode *inode, struct file *filep) { struct drm_crtc *crtc = inode->i_private; @@ -160,8 +166,19 @@ static int crtc_crc_open(struct inode *inode, struct file *filep) crc->entries = entries; crc->values_cnt = values_cnt; crc->opened = true; + + /* + * Only return once we got a first frame, so userspace doesn't have to + * guess when this particular piece of HW will be ready to start + * generating CRCs. + */ + ret = wait_event_interruptible_lock_irq(crc->wq, + crtc_crc_data_count(crc), + crc->lock); spin_unlock_irq(&crc->lock); + WARN_ON(ret); + return 0; err_disable: @@ -189,12 +206,6 @@ static int crtc_crc_release(struct inode *inode, struct file *filep) return 0; } -static int crtc_crc_data_count(struct drm_crtc_crc *crc) -{ - assert_spin_locked(&crc->lock); - return CIRC_CNT(crc->head, crc->tail, DRM_CRC_ENTRIES_NR); -} - /* * 1 frame field of 10 chars plus a number of CRC fields of 10 chars each, space * separated, with a newline at the end and null-terminated. @@ -325,16 +336,19 @@ int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame, struct drm_crtc_crc_entry *entry; int head, tail; - assert_spin_locked(&crc->lock); + spin_lock(&crc->lock); /* Caller may not have noticed yet that userspace has stopped reading */ - if (!crc->opened) + if (!crc->opened) { + spin_unlock(&crc->lock); return -EINVAL; + } head = crc->head; tail = crc->tail; if (CIRC_SPACE(head, tail, DRM_CRC_ENTRIES_NR) < 1) { + spin_unlock(&crc->lock); DRM_ERROR("Overflow of CRC buffer, userspace reads too slow.\n"); return -ENOBUFS; } @@ -347,6 +361,10 @@ int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame, head = (head + 1) & (DRM_CRC_ENTRIES_NR - 1); crc->head = head; + spin_unlock(&crc->lock); + + wake_up_interruptible(&crc->wq); + return 0; } EXPORT_SYMBOL_GPL(drm_crtc_add_crc_entry); |