Commit 8c5c6fad authored by Dan Carpenter's avatar Dan Carpenter Committed by Alex Deucher
Browse files

drm/radeon: signedness bug in kv_dpm.c 



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: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 41cd0b3b

drivers/gpu/drm/radeon/kv_dpm.c

+13 −19
Original line number Diff line number Diff line
@@ -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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