Once channel's job is hung, it dumps the channel's state into KMSG before tearing down the offending job. If multiple channels hang at once, then they dump messages simultaneously, making the debug info unreadable, and thus, useless. This patch adds mutex which allows only one channel to emit debug messages at a time. Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx> --- drivers/gpu/host1x/debug.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/host1x/debug.c b/drivers/gpu/host1x/debug.c index c0392672a842..1b4997bda1c7 100644 --- a/drivers/gpu/host1x/debug.c +++ b/drivers/gpu/host1x/debug.c @@ -16,6 +16,8 @@ #include "debug.h" #include "channel.h" +static DEFINE_MUTEX(debug_lock); + unsigned int host1x_debug_trace_cmdbuf; static pid_t host1x_debug_force_timeout_pid; @@ -52,12 +54,14 @@ static int show_channel(struct host1x_channel *ch, void *data, bool show_fifo) struct output *o = data; mutex_lock(&ch->cdma.lock); + mutex_lock(&debug_lock); if (show_fifo) host1x_hw_show_channel_fifo(m, ch, o); host1x_hw_show_channel_cdma(m, ch, o); + mutex_unlock(&debug_lock); mutex_unlock(&ch->cdma.lock); return 0; -- 2.26.0
