drm/amdgpu: fix error handling in df_v3_6_pmc_start

When df_v3_6_pmc_get_ctrl_settings() fails for some reason, we
store uninitialized data in a register, as gcc points out:

drivers/gpu/drm/amd/amdgpu/df_v3_6.c: In function 'df_v3_6_pmc_start':
drivers/gpu/drm/amd/amdgpu/amdgpu.h:1012:29: error: 'lo_val' may be used uninitialized in this function [-Werror=maybe-uninitialized]
 #define WREG32_PCIE(reg, v) adev->pcie_wreg(adev, (reg), (v))
                             ^~~~
drivers/gpu/drm/amd/amdgpu/df_v3_6.c:334:39: note: 'lo_val' was declared here
  uint32_t lo_base_addr, hi_base_addr, lo_val, hi_val;
                                       ^~~~~~

Make it return a proper error code that we can catch in the caller.

Fixes: 992af942a6cf ("drm/amdgpu: add df perfmon regs and funcs for xgmi")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/df_v3_6.c b/drivers/gpu/drm/amd/amdgpu/df_v3_6.c
index 8c09bf994acd568357d7bed8dd0e332a9f733468..e079ee066d8768353536dd3f7a7c91ed727d9d47 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/df_v3_6.c
+++ b/drivers/gpu/drm/amd/amdgpu/df_v3_6.c
@@ -177,7 +177,7 @@ static void df_v3_6_pmc_get_read_settings(struct amdgpu_device *adev,
 }
 
 /* get control counter settings i.e. address and values to set */
-static void df_v3_6_pmc_get_ctrl_settings(struct amdgpu_device *adev,
+static int df_v3_6_pmc_get_ctrl_settings(struct amdgpu_device *adev,
                                          uint64_t config,
                                          uint32_t *lo_base_addr,
                                          uint32_t *hi_base_addr,
@@ -191,12 +191,12 @@ static void df_v3_6_pmc_get_ctrl_settings(struct amdgpu_device *adev,
        df_v3_6_pmc_get_addr(adev, config, 1, lo_base_addr, hi_base_addr);
 
        if (lo_val == NULL || hi_val == NULL)
-               return;
+               return -EINVAL;
 
        if ((*lo_base_addr == 0) || (*hi_base_addr == 0)) {
                DRM_ERROR("DF PMC addressing not retrieved! Lo: %x, Hi: %x",
                                *lo_base_addr, *hi_base_addr);
-               return;
+               return -ENXIO;
        }
 
        eventsel = GET_EVENT(config);
@@ -211,6 +211,8 @@ static void df_v3_6_pmc_get_ctrl_settings(struct amdgpu_device *adev,
        es_7_0 = es_13_0 & 0x0FFUL;
        *lo_val = (es_7_0 & 0xFFUL) | ((unitmask & 0x0FUL) << 8);
        *hi_val = (es_11_8 | ((es_13_12)<<(29)));
+
+       return 0;
 }
 
 /* assign df performance counters for read */
@@ -345,13 +347,16 @@ static int df_v3_6_add_xgmi_link_cntr(struct amdgpu_device *adev,
        if (ret || is_assigned)
                return ret;
 
-       df_v3_6_pmc_get_ctrl_settings(adev,
+       ret = df_v3_6_pmc_get_ctrl_settings(adev,
                        config,
                        &lo_base_addr,
                        &hi_base_addr,
                        &lo_val,
                        &hi_val);
 
+       if (ret)
+               return ret;
+
        WREG32_PCIE(lo_base_addr, lo_val);
        WREG32_PCIE(hi_base_addr, hi_val);