Re: [PATCH] drm/amd/powerplay/hwmgr: Remove null check before kfree

From: Harry Wentland
Date: Tue Aug 29 2017 - 09:34:17 EST


On 2017-08-29 09:12 AM, Himanshu Jha wrote:
> kfree on NULL pointer is a no-op and therefore checking is redundant.
>
> Signed-off-by: Himanshu Jha <himanshujha199640@xxxxxxxxx>

Reviewed-by: Harry Wentland <harry.wentland@xxxxxxx>

Harry

> ---
> drivers/gpu/drm/amd/powerplay/hwmgr/cz_hwmgr.c | 6 +-
> .../gpu/drm/amd/powerplay/hwmgr/processpptables.c | 96 ++++++++--------------
> drivers/gpu/drm/amd/powerplay/hwmgr/rv_hwmgr.c | 52 ++++--------
> drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c | 12 +--
> 4 files changed, 56 insertions(+), 110 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/cz_hwmgr.c b/drivers/gpu/drm/amd/powerplay/hwmgr/cz_hwmgr.c
> index bc839ff..9f2c037 100644
> --- a/drivers/gpu/drm/amd/powerplay/hwmgr/cz_hwmgr.c
> +++ b/drivers/gpu/drm/amd/powerplay/hwmgr/cz_hwmgr.c
> @@ -1225,10 +1225,8 @@ static int cz_hwmgr_backend_fini(struct pp_hwmgr *hwmgr)
> phm_destroy_table(hwmgr, &(hwmgr->power_down_asic));
> phm_destroy_table(hwmgr, &(hwmgr->setup_asic));
>
> - if (NULL != hwmgr->dyn_state.vddc_dep_on_dal_pwrl) {
> - kfree(hwmgr->dyn_state.vddc_dep_on_dal_pwrl);
> - hwmgr->dyn_state.vddc_dep_on_dal_pwrl = NULL;
> - }
> + kfree(hwmgr->dyn_state.vddc_dep_on_dal_pwrl);
> + hwmgr->dyn_state.vddc_dep_on_dal_pwrl = NULL;
>
> kfree(hwmgr->backend);
> hwmgr->backend = NULL;
> diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/processpptables.c b/drivers/gpu/drm/amd/powerplay/hwmgr/processpptables.c
> index 2716721..a6dbc55 100644
> --- a/drivers/gpu/drm/amd/powerplay/hwmgr/processpptables.c
> +++ b/drivers/gpu/drm/amd/powerplay/hwmgr/processpptables.c
> @@ -1615,85 +1615,53 @@ static int pp_tables_uninitialize(struct pp_hwmgr *hwmgr)
> if (hwmgr->chip_id == CHIP_RAVEN)
> return 0;
>
> - if (NULL != hwmgr->dyn_state.vddc_dependency_on_sclk) {
> - kfree(hwmgr->dyn_state.vddc_dependency_on_sclk);
> - hwmgr->dyn_state.vddc_dependency_on_sclk = NULL;
> - }
> + kfree(hwmgr->dyn_state.vddc_dependency_on_sclk);
> + hwmgr->dyn_state.vddc_dependency_on_sclk = NULL;
>
> - if (NULL != hwmgr->dyn_state.vddci_dependency_on_mclk) {
> - kfree(hwmgr->dyn_state.vddci_dependency_on_mclk);
> - hwmgr->dyn_state.vddci_dependency_on_mclk = NULL;
> - }
> + kfree(hwmgr->dyn_state.vddci_dependency_on_mclk);
> + hwmgr->dyn_state.vddci_dependency_on_mclk = NULL;
>
> - if (NULL != hwmgr->dyn_state.vddc_dependency_on_mclk) {
> - kfree(hwmgr->dyn_state.vddc_dependency_on_mclk);
> - hwmgr->dyn_state.vddc_dependency_on_mclk = NULL;
> - }
> + kfree(hwmgr->dyn_state.vddc_dependency_on_mclk);
> + hwmgr->dyn_state.vddc_dependency_on_mclk = NULL;
>
> - if (NULL != hwmgr->dyn_state.mvdd_dependency_on_mclk) {
> - kfree(hwmgr->dyn_state.mvdd_dependency_on_mclk);
> - hwmgr->dyn_state.mvdd_dependency_on_mclk = NULL;
> - }
> + kfree(hwmgr->dyn_state.mvdd_dependency_on_mclk);
> + hwmgr->dyn_state.mvdd_dependency_on_mclk = NULL;
>
> - if (NULL != hwmgr->dyn_state.valid_mclk_values) {
> - kfree(hwmgr->dyn_state.valid_mclk_values);
> - hwmgr->dyn_state.valid_mclk_values = NULL;
> - }
> + kfree(hwmgr->dyn_state.valid_mclk_values);
> + hwmgr->dyn_state.valid_mclk_values = NULL;
>
> - if (NULL != hwmgr->dyn_state.valid_sclk_values) {
> - kfree(hwmgr->dyn_state.valid_sclk_values);
> - hwmgr->dyn_state.valid_sclk_values = NULL;
> - }
> + kfree(hwmgr->dyn_state.valid_sclk_values);
> + hwmgr->dyn_state.valid_sclk_values = NULL;
>
> - if (NULL != hwmgr->dyn_state.cac_leakage_table) {
> - kfree(hwmgr->dyn_state.cac_leakage_table);
> - hwmgr->dyn_state.cac_leakage_table = NULL;
> - }
> + kfree(hwmgr->dyn_state.cac_leakage_table);
> + hwmgr->dyn_state.cac_leakage_table = NULL;
>
> - if (NULL != hwmgr->dyn_state.vddc_phase_shed_limits_table) {
> - kfree(hwmgr->dyn_state.vddc_phase_shed_limits_table);
> - hwmgr->dyn_state.vddc_phase_shed_limits_table = NULL;
> - }
> + kfree(hwmgr->dyn_state.vddc_phase_shed_limits_table);
> + hwmgr->dyn_state.vddc_phase_shed_limits_table = NULL;
>
> - if (NULL != hwmgr->dyn_state.vce_clock_voltage_dependency_table) {
> - kfree(hwmgr->dyn_state.vce_clock_voltage_dependency_table);
> - hwmgr->dyn_state.vce_clock_voltage_dependency_table = NULL;
> - }
> + kfree(hwmgr->dyn_state.vce_clock_voltage_dependency_table);
> + hwmgr->dyn_state.vce_clock_voltage_dependency_table = NULL;
>
> - if (NULL != hwmgr->dyn_state.uvd_clock_voltage_dependency_table) {
> - kfree(hwmgr->dyn_state.uvd_clock_voltage_dependency_table);
> - hwmgr->dyn_state.uvd_clock_voltage_dependency_table = NULL;
> - }
> + kfree(hwmgr->dyn_state.uvd_clock_voltage_dependency_table);
> + hwmgr->dyn_state.uvd_clock_voltage_dependency_table = NULL;
>
> - if (NULL != hwmgr->dyn_state.samu_clock_voltage_dependency_table) {
> - kfree(hwmgr->dyn_state.samu_clock_voltage_dependency_table);
> - hwmgr->dyn_state.samu_clock_voltage_dependency_table = NULL;
> - }
> + kfree(hwmgr->dyn_state.samu_clock_voltage_dependency_table);
> + hwmgr->dyn_state.samu_clock_voltage_dependency_table = NULL;
>
> - if (NULL != hwmgr->dyn_state.acp_clock_voltage_dependency_table) {
> - kfree(hwmgr->dyn_state.acp_clock_voltage_dependency_table);
> - hwmgr->dyn_state.acp_clock_voltage_dependency_table = NULL;
> - }
> + kfree(hwmgr->dyn_state.acp_clock_voltage_dependency_table);
> + hwmgr->dyn_state.acp_clock_voltage_dependency_table = NULL;
>
> - if (NULL != hwmgr->dyn_state.cac_dtp_table) {
> - kfree(hwmgr->dyn_state.cac_dtp_table);
> - hwmgr->dyn_state.cac_dtp_table = NULL;
> - }
> + kfree(hwmgr->dyn_state.cac_dtp_table);
> + hwmgr->dyn_state.cac_dtp_table = NULL;
>
> - if (NULL != hwmgr->dyn_state.ppm_parameter_table) {
> - kfree(hwmgr->dyn_state.ppm_parameter_table);
> - hwmgr->dyn_state.ppm_parameter_table = NULL;
> - }
> + kfree(hwmgr->dyn_state.ppm_parameter_table);
> + hwmgr->dyn_state.ppm_parameter_table = NULL;
>
> - if (NULL != hwmgr->dyn_state.vdd_gfx_dependency_on_sclk) {
> - kfree(hwmgr->dyn_state.vdd_gfx_dependency_on_sclk);
> - hwmgr->dyn_state.vdd_gfx_dependency_on_sclk = NULL;
> - }
> + kfree(hwmgr->dyn_state.vdd_gfx_dependency_on_sclk);
> + hwmgr->dyn_state.vdd_gfx_dependency_on_sclk = NULL;
>
> - if (NULL != hwmgr->dyn_state.vq_budgeting_table) {
> - kfree(hwmgr->dyn_state.vq_budgeting_table);
> - hwmgr->dyn_state.vq_budgeting_table = NULL;
> - }
> + kfree(hwmgr->dyn_state.vq_budgeting_table);
> + hwmgr->dyn_state.vq_budgeting_table = NULL;
>
> return 0;
> }
> diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/rv_hwmgr.c b/drivers/gpu/drm/amd/powerplay/hwmgr/rv_hwmgr.c
> index 2c3e6ba..5547ed3 100644
> --- a/drivers/gpu/drm/amd/powerplay/hwmgr/rv_hwmgr.c
> +++ b/drivers/gpu/drm/amd/powerplay/hwmgr/rv_hwmgr.c
> @@ -640,40 +640,24 @@ static int rv_hwmgr_backend_fini(struct pp_hwmgr *hwmgr)
> phm_destroy_table(hwmgr, &(hwmgr->power_down_asic));
> phm_destroy_table(hwmgr, &(hwmgr->setup_asic));
>
> - if (pinfo->vdd_dep_on_dcefclk) {
> - kfree(pinfo->vdd_dep_on_dcefclk);
> - pinfo->vdd_dep_on_dcefclk = NULL;
> - }
> - if (pinfo->vdd_dep_on_socclk) {
> - kfree(pinfo->vdd_dep_on_socclk);
> - pinfo->vdd_dep_on_socclk = NULL;
> - }
> - if (pinfo->vdd_dep_on_fclk) {
> - kfree(pinfo->vdd_dep_on_fclk);
> - pinfo->vdd_dep_on_fclk = NULL;
> - }
> - if (pinfo->vdd_dep_on_dispclk) {
> - kfree(pinfo->vdd_dep_on_dispclk);
> - pinfo->vdd_dep_on_dispclk = NULL;
> - }
> - if (pinfo->vdd_dep_on_dppclk) {
> - kfree(pinfo->vdd_dep_on_dppclk);
> - pinfo->vdd_dep_on_dppclk = NULL;
> - }
> - if (pinfo->vdd_dep_on_phyclk) {
> - kfree(pinfo->vdd_dep_on_phyclk);
> - pinfo->vdd_dep_on_phyclk = NULL;
> - }
> -
> - if (NULL != hwmgr->dyn_state.vddc_dep_on_dal_pwrl) {
> - kfree(hwmgr->dyn_state.vddc_dep_on_dal_pwrl);
> - hwmgr->dyn_state.vddc_dep_on_dal_pwrl = NULL;
> - }
> -
> - if (NULL != hwmgr->dyn_state.vq_budgeting_table) {
> - kfree(hwmgr->dyn_state.vq_budgeting_table);
> - hwmgr->dyn_state.vq_budgeting_table = NULL;
> - }
> + kfree(pinfo->vdd_dep_on_dcefclk);
> + pinfo->vdd_dep_on_dcefclk = NULL;
> + kfree(pinfo->vdd_dep_on_socclk);
> + pinfo->vdd_dep_on_socclk = NULL;
> + kfree(pinfo->vdd_dep_on_fclk);
> + pinfo->vdd_dep_on_fclk = NULL;
> + kfree(pinfo->vdd_dep_on_dispclk);
> + pinfo->vdd_dep_on_dispclk = NULL;
> + kfree(pinfo->vdd_dep_on_dppclk);
> + pinfo->vdd_dep_on_dppclk = NULL;
> + kfree(pinfo->vdd_dep_on_phyclk);
> + pinfo->vdd_dep_on_phyclk = NULL;
> +
> + kfree(hwmgr->dyn_state.vddc_dep_on_dal_pwrl);
> + hwmgr->dyn_state.vddc_dep_on_dal_pwrl = NULL;
> +
> + kfree(hwmgr->dyn_state.vq_budgeting_table);
> + hwmgr->dyn_state.vq_budgeting_table = NULL;
>
> kfree(hwmgr->backend);
> hwmgr->backend = NULL;
> diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c b/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c
> index c274323..eb8a3ff 100644
> --- a/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c
> +++ b/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c
> @@ -2282,15 +2282,11 @@ static int smu7_set_private_data_based_on_pptable_v0(struct pp_hwmgr *hwmgr)
>
> static int smu7_hwmgr_backend_fini(struct pp_hwmgr *hwmgr)
> {
> - if (NULL != hwmgr->dyn_state.vddc_dep_on_dal_pwrl) {
> - kfree(hwmgr->dyn_state.vddc_dep_on_dal_pwrl);
> - hwmgr->dyn_state.vddc_dep_on_dal_pwrl = NULL;
> - }
> + kfree(hwmgr->dyn_state.vddc_dep_on_dal_pwrl);
> + hwmgr->dyn_state.vddc_dep_on_dal_pwrl = NULL;
> pp_smu7_thermal_fini(hwmgr);
> - if (NULL != hwmgr->backend) {
> - kfree(hwmgr->backend);
> - hwmgr->backend = NULL;
> - }
> + kfree(hwmgr->backend);
> + hwmgr->backend = NULL;
>
> return 0;
> }
>