[PATCH] drm: radeon: ci_dpm: Add error handling for ci_send_msg_to_smc_with_parameter()

[Wentao Liang]

The ci_enable_uvd_dpm() calls ci_send_msg_to_smc_with_parameter()
but does not check the return value. This could lead to the execution
with potentially invalid data. A proper implementation can be found
in the ci_fan_ctrl_start_smc_fan_control().

Add a check after calling ci_send_msg_to_smc_with_parameter(), return
-EINVAL if the sending fails.

Fixes: cc8dbbb4f62a ("drm/radeon: add dpm support for CI dGPUs (v2)")
Cc: sta...@vger.kernel.org # v3.12
Signed-off-by: Wentao Liang <vu...@iscas.ac.cn>
---
 drivers/gpu/drm/radeon/ci_dpm.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/radeon/ci_dpm.c b/drivers/gpu/drm/radeon/ci_dpm.c
index abe9d65cc460..3877863c6893 100644
--- a/drivers/gpu/drm/radeon/ci_dpm.c
+++ b/drivers/gpu/drm/radeon/ci_dpm.c
@@ -3889,6 +3889,7 @@ static int ci_enable_uvd_dpm(struct radeon_device *rdev, 
bool enable)
        struct ci_power_info *pi = ci_get_pi(rdev);
        const struct radeon_clock_and_voltage_limits *max_limits;
        int i;
+       PPSMC_Result result;
 
        if (rdev->pm.dpm.ac_power)
                max_limits = &rdev->pm.dpm.dyn_state.max_clock_voltage_on_ac;
@@ -3907,24 +3908,30 @@ static int ci_enable_uvd_dpm(struct radeon_device 
*rdev, bool enable)
                        }
                }
 
-               ci_send_msg_to_smc_with_parameter(rdev,
+               result = ci_send_msg_to_smc_with_parameter(rdev,
                                                  
PPSMC_MSG_UVDDPM_SetEnabledMask,
                                                  
pi->dpm_level_enable_mask.uvd_dpm_enable_mask);
+               if (result != PPSMC_Result_OK)
+                       return -EINVAL;
 
                if (pi->last_mclk_dpm_enable_mask & 0x1) {
                        pi->uvd_enabled = true;
                        pi->dpm_level_enable_mask.mclk_dpm_enable_mask &= 
0xFFFFFFFE;
-                       ci_send_msg_to_smc_with_parameter(rdev,
+                       result = ci_send_msg_to_smc_with_parameter(rdev,
                                                          
PPSMC_MSG_MCLKDPM_SetEnabledMask,
                                                          
pi->dpm_level_enable_mask.mclk_dpm_enable_mask);
+                       if (result != PPSMC_Result_OK)
+                               return -EINVAL;
                }
        } else {
                if (pi->last_mclk_dpm_enable_mask & 0x1) {
                        pi->uvd_enabled = false;
                        pi->dpm_level_enable_mask.mclk_dpm_enable_mask |= 1;
-                       ci_send_msg_to_smc_with_parameter(rdev,
+                       result = ci_send_msg_to_smc_with_parameter(rdev,
                                                          
PPSMC_MSG_MCLKDPM_SetEnabledMask,
                                                          
pi->dpm_level_enable_mask.mclk_dpm_enable_mask);
+                       if (result != PPSMC_Result_OK)
+                               return -EINVAL;
                }
        }
 
-- 
2.42.0.windows.2