diff options
| -rw-r--r-- | drivers/hv/ring_buffer.c | 13 | ||||
| -rw-r--r-- | drivers/video/fbdev/hyperv_fb.c | 8 | ||||
| -rw-r--r-- | include/linux/hyperv.h | 2 |
3 files changed, 22 insertions, 1 deletions
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index 769851b6e74c..7ed6fad3fa8f 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -246,6 +246,19 @@ void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info) mutex_unlock(&ring_info->ring_buffer_mutex); } +/* + * Check if the ring buffer spinlock is available to take or not; used on + * atomic contexts, like panic path (see the Hyper-V framebuffer driver). + */ + +bool hv_ringbuffer_spinlock_busy(struct vmbus_channel *channel) +{ + struct hv_ring_buffer_info *rinfo = &channel->outbound; + + return spin_is_locked(&rinfo->ring_lock); +} +EXPORT_SYMBOL_GPL(hv_ringbuffer_spinlock_busy); + /* Write to the ring buffer. */ int hv_ringbuffer_write(struct vmbus_channel *channel, const struct kvec *kv_list, u32 kv_count) diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c index 40baa79f8046..f0a66a344d87 100644 --- a/drivers/video/fbdev/hyperv_fb.c +++ b/drivers/video/fbdev/hyperv_fb.c @@ -798,12 +798,18 @@ static void hvfb_ondemand_refresh_throttle(struct hvfb_par *par, static int hvfb_on_panic(struct notifier_block *nb, unsigned long e, void *p) { + struct hv_device *hdev; struct hvfb_par *par; struct fb_info *info; par = container_of(nb, struct hvfb_par, hvfb_panic_nb); - par->synchronous_fb = true; info = par->info; + hdev = device_to_hv_device(info->device); + + if (hv_ringbuffer_spinlock_busy(hdev->channel)) + return NOTIFY_DONE; + + par->synchronous_fb = true; if (par->need_docopy) hvfb_docopy(par, 0, dio_fb_size); synthvid_update(info, 0, 0, INT_MAX, INT_MAX); diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 1ce131f29f3b..eada4d8d6587 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1269,6 +1269,8 @@ struct hv_ring_buffer_debug_info { int hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info, struct hv_ring_buffer_debug_info *debug_info); +bool hv_ringbuffer_spinlock_busy(struct vmbus_channel *channel); + /* Vmbus interface */ #define vmbus_driver_register(driver) \ __vmbus_driver_register(driver, THIS_MODULE, KBUILD_MODNAME) |