drm/i915: Initialise outparam for error return from wait_for_register

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'.

References: 3f649ab728cd ("treewide: Remove uninitialized_var() usage")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200916105022.28316-1-chris@chris-wilson.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Chris Wilson 2020-09-16 11:50:21 +01:00 committed by Greg Kroah-Hartman
parent 99036f1aed
commit fff826d665

View File

@ -1926,13 +1926,14 @@ int __intel_wait_for_register_fw(struct intel_uncore *uncore,
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)