From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> commit b79ffa914ede785a721f42d8ee3ce7b8eeede2bb upstream. Just in case the caller passes in 0 for both slow&fast timeouts, make sure we initialise the stack value returned. Add an assert so that we don't make the mistake of passing 0 timeouts for the wait. drivers/gpu/drm/i915/intel_uncore.c:2011 __intel_wait_for_register_fw() error: uninitialized symbol 'reg_value'. Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Reviewed-by: José Roberto de Souza <jose.souza@xxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20200916105022.28316-1-chris@xxxxxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/intel_uncore.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/i915/intel_uncore.c +++ b/drivers/gpu/drm/i915/intel_uncore.c @@ -1926,13 +1926,14 @@ int __intel_wait_for_register_fw(struct unsigned int slow_timeout_ms, u32 *out_value) { - u32 reg_value; + u32 reg_value = 0; #define done (((reg_value = intel_uncore_read_fw(uncore, reg)) & mask) == value) int ret; /* Catch any overuse of this function */ might_sleep_if(slow_timeout_ms); GEM_BUG_ON(fast_timeout_us > 20000); + GEM_BUG_ON(!fast_timeout_us && !slow_timeout_ms); ret = -ETIMEDOUT; if (fast_timeout_us && fast_timeout_us <= 20000)
