From: Dmitry Osipenko digetx@gmail.com
[ Upstream commit 35681862808472a0a4b9a8817ae2789c0b5b3edc ]
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@gmail.com Signed-off-by: Thierry Reding treding@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 c0392672a8421..1b4997bda1c79 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;