The patch below does not apply to the 4.17-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From c4ff91dd40e2253ab6dd028011469c2c694e1e19 Mon Sep 17 00:00:00 2001
From: Colin Ian King colin.king@canonical.com Date: Wed, 6 Jun 2018 13:18:31 +0100 Subject: [PATCH] drm/amd/pp: initialize result to before or'ing in data
The current use of result is or'ing in values and checking for a non-zero result, however, result is not initialized to zero so it potentially contains garbage to start with. Fix this by initializing it to the first return from the call to vega10_program_didt_config_registers.
Detected by cppcheck: "(error) Uninitialized variable: result"
Fixes: 9b7b8154cdb8 ("drm/amd/powerplay: added didt support for vega10") Signed-off-by: Colin Ian King colin.king@canonical.com Acked-by: Huang Rui ray.huang@amd.com [Fix the subject as Colin's comment] Signed-off-by: Huang Rui ray.huang@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org
diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_powertune.c b/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_powertune.c index a9efd8554fbc..dbe4b1f66784 100644 --- a/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_powertune.c +++ b/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_powertune.c @@ -1104,7 +1104,7 @@ static int vega10_enable_psm_gc_edc_config(struct pp_hwmgr *hwmgr) for (count = 0; count < num_se; count++) { data = GRBM_GFX_INDEX__INSTANCE_BROADCAST_WRITES_MASK | GRBM_GFX_INDEX__SH_BROADCAST_WRITES_MASK | ( count << GRBM_GFX_INDEX__SE_INDEX__SHIFT); WREG32_SOC15(GC, 0, mmGRBM_GFX_INDEX, data); - result |= vega10_program_didt_config_registers(hwmgr, PSMSEEDCStallPatternConfig_Vega10, VEGA10_CONFIGREG_DIDT); + result = vega10_program_didt_config_registers(hwmgr, PSMSEEDCStallPatternConfig_Vega10, VEGA10_CONFIGREG_DIDT); result |= vega10_program_didt_config_registers(hwmgr, PSMSEEDCStallDelayConfig_Vega10, VEGA10_CONFIGREG_DIDT); result |= vega10_program_didt_config_registers(hwmgr, PSMSEEDCCtrlResetConfig_Vega10, VEGA10_CONFIGREG_DIDT); result |= vega10_program_didt_config_registers(hwmgr, PSMSEEDCCtrlConfig_Vega10, VEGA10_CONFIGREG_DIDT);