On Wed, Sep 4, 2013 at 5:31 AM, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
> The problem here is that "unsigned i" is always greater than or equal to
> zero. These loops mostly have a second check for "(i == 0)" so only the
> last two are actually buggy. The rest is just cleanup.
>
> Bug 1: kv_force_dpm_highest() doesn't have an "(i == 0)" check so it's
> a potential forever loop.
>
> Bug 2: In kv_get_sleep_divider_id_from_clock() there is a typo and the
> test is reversed "<=" vs ">" so we never enter the loop. That means
> normally we return KV_MAX_DEEPSLEEP_DIVIDER_ID (5). The return value
> from here is saved in ->DeepSleepDivId and I wasn't able to determine
> how that is used. This is a static checker fix and I have not tested
> it.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Applied. thanks!
Alex
> ---
> I considered making "i" signed but that doesn't actually change anything
> because the tests have to end on zero anyway.
>
> diff --git a/drivers/gpu/drm/radeon/kv_dpm.c b/drivers/gpu/drm/radeon/kv_dpm.c
> index ecd6080..c499daf 100644
> --- a/drivers/gpu/drm/radeon/kv_dpm.c
> +++ b/drivers/gpu/drm/radeon/kv_dpm.c
> @@ -667,9 +667,8 @@ static int kv_program_bootup_state(struct radeon_device *rdev)
> &rdev->pm.dpm.dyn_state.vddc_dependency_on_sclk;
>
> if (table && table->count) {
> - for (i = pi->graphics_dpm_level_count - 1; i >= 0; i--) {
> - if ((table->entries[i].clk == pi->boot_pl.sclk) ||
> - (i == 0))
> + for (i = pi->graphics_dpm_level_count - 1; i > 0; i--) {
> + if (table->entries[i].clk == pi->boot_pl.sclk)
> break;
> }
>
> @@ -682,9 +681,8 @@ static int kv_program_bootup_state(struct radeon_device *rdev)
> if (table->num_max_dpm_entries == 0)
> return -EINVAL;
>
> - for (i = pi->graphics_dpm_level_count - 1; i >= 0; i--) {
> - if ((table->entries[i].sclk_frequency == pi->boot_pl.sclk) ||
> - (i == 0))
> + for (i = pi->graphics_dpm_level_count - 1; i > 0; i--) {
> + if (table->entries[i].sclk_frequency == pi->boot_pl.sclk)
> break;
> }
>
> @@ -1588,13 +1586,11 @@ static void kv_set_valid_clock_range(struct radeon_device *rdev,
> }
> }
>
> - for (i = pi->graphics_dpm_level_count - 1; i >= 0; i--) {
> - if ((table->entries[i].clk <= new_ps->levels[new_ps->num_levels -1].sclk) ||
> - (i == 0)) {
> - pi->highest_valid = i;
> + for (i = pi->graphics_dpm_level_count - 1; i > 0; i--) {
> + if (table->entries[i].clk <= new_ps->levels[new_ps->num_levels - 1].sclk)
> break;
> - }
> }
> + pi->highest_valid = i;
>
> if (pi->lowest_valid > pi->highest_valid) {
> if ((new_ps->levels[0].sclk - table->entries[pi->highest_valid].clk) >
> @@ -1615,14 +1611,12 @@ static void kv_set_valid_clock_range(struct radeon_device *rdev,
> }
> }
>
> - for (i = pi->graphics_dpm_level_count - 1; i >= 0; i--) {
> + for (i = pi->graphics_dpm_level_count - 1; i > 0; i--) {
> if (table->entries[i].sclk_frequency <=
> - new_ps->levels[new_ps->num_levels - 1].sclk ||
> - i == 0) {
> - pi->highest_valid = i;
> + new_ps->levels[new_ps->num_levels - 1].sclk)
> break;
> - }
> }
> + pi->highest_valid = i;
>
> if (pi->lowest_valid > pi->highest_valid) {
> if ((new_ps->levels[0].sclk -
> @@ -1871,7 +1865,7 @@ static int kv_force_dpm_highest(struct radeon_device *rdev)
> if (ret)
> return ret;
>
> - for (i = SMU7_MAX_LEVELS_GRAPHICS - 1; i >= 0; i--) {
> + for (i = SMU7_MAX_LEVELS_GRAPHICS - 1; i > 0; i--) {
> if (enable_mask & (1 << i))
> break;
> }
> @@ -1911,9 +1905,9 @@ static u8 kv_get_sleep_divider_id_from_clock(struct radeon_device *rdev,
> if (!pi->caps_sclk_ds)
> return 0;
>
> - for (i = KV_MAX_DEEPSLEEP_DIVIDER_ID; i <= 0; i--) {
> + for (i = KV_MAX_DEEPSLEEP_DIVIDER_ID; i > 0; i--) {
> temp = sclk / sumo_get_sleep_divider_from_id(i);
> - if ((temp >= min) || (i == 0))
> + if (temp >= min)
> break;
> }
>
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