[PATCH 5.9 13/15] Revert "drm/amdgpu: Fix NULL dereference in dpm sysfs handlers"

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Alex Deucher <alexander.deucher@amd.com>

commit 2456c290a7889be492cb96092b62d16c11176f72 upstream.

This regressed some working configurations so revert it.  Will
fix this properly for 5.9 and backport then.

This reverts commit 38e0c89a19fd13f28d2b4721035160a3e66e270b.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
@@ -796,7 +796,8 @@ static ssize_t amdgpu_set_pp_od_clk_volt
 		tmp_str++;
 	while (isspace(*++tmp_str));
 
-	while ((sub_str = strsep(&tmp_str, delimiter)) != NULL) {
+	while (tmp_str[0]) {
+		sub_str = strsep(&tmp_str, delimiter);
 		ret = kstrtol(sub_str, 0, &parameter[parameter_size]);
 		if (ret)
 			return -EINVAL;
@@ -1066,7 +1067,8 @@ static ssize_t amdgpu_read_mask(const ch
 	memcpy(buf_cpy, buf, bytes);
 	buf_cpy[bytes] = '\0';
 	tmp = buf_cpy;
-	while ((sub_str = strsep(&tmp, delimiter)) != NULL) {
+	while (tmp[0]) {
+		sub_str = strsep(&tmp, delimiter);
 		if (strlen(sub_str)) {
 			ret = kstrtol(sub_str, 0, &level);
 			if (ret)
@@ -1695,7 +1697,8 @@ static ssize_t amdgpu_set_pp_power_profi
 			i++;
 		memcpy(buf_cpy, buf, count-i);
 		tmp_str = buf_cpy;
-		while ((sub_str = strsep(&tmp_str, delimiter)) != NULL) {
+		while (tmp_str[0]) {
+			sub_str = strsep(&tmp_str, delimiter);
 			ret = kstrtol(sub_str, 0, &parameter[parameter_size]);
 			if (ret)
 				return -EINVAL;