drm/nouveau: fix potential accuracy loss when parsing perf 0x1c tables

Reported-by: Roy Spliet <r.spliet@student.tudelft.nl>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 14 insertions, 20 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_perf.c b/drivers/gpu/drm/nouveau/nouveau_perf.c
index a882a366487f..a397420e46c6 100644
--- a/drivers/gpu/drm/nouveau/nouveau_perf.c
+++ b/drivers/gpu/drm/nouveau/nouveau_perf.c
@@ -90,50 +90,44 @@ nouveau_perf_init(struct drm_device *dev)
                 case 0x15:
                         perflvl->fanspeed = entry[55];
                         perflvl->voltage = entry[56];
-                        perflvl->core = ROM32(entry[1]) / 100;
-                        perflvl->memory = ROM32(entry[5]) / 100;
+                        perflvl->core = ROM32(entry[1]) * 10;
+                        perflvl->memory = ROM32(entry[5]) * 10;
                         break;
                 case 0x21:
                 case 0x23:
                 case 0x24:
                         perflvl->fanspeed = entry[4];
                         perflvl->voltage = entry[5];
-                        perflvl->core = ROM16(entry[6]);
-                        perflvl->memory = ROM16(entry[11]);
+                        perflvl->core = ROM16(entry[6]) * 1000;
+                        perflvl->memory = ROM16(entry[11]) * 1000;
                         break;
                 case 0x25:
                         perflvl->fanspeed = entry[4];
                         perflvl->voltage = entry[5];
-                        perflvl->core = ROM16(entry[6]);
-                        perflvl->shader = ROM16(entry[10]);
-                        perflvl->memory = ROM16(entry[12]);
+                        perflvl->core = ROM16(entry[6]) * 1000;
+                        perflvl->shader = ROM16(entry[10]) * 1000;
+                        perflvl->memory = ROM16(entry[12]) * 1000;
                         break;
                 case 0x30:
                 case 0x35:
                         perflvl->fanspeed = entry[6];
                         perflvl->voltage = entry[7];
-                        perflvl->core = ROM16(entry[8]);
-                        perflvl->shader = ROM16(entry[10]);
-                        perflvl->memory = ROM16(entry[12]);
+                        perflvl->core = ROM16(entry[8]) * 1000;
+                        perflvl->shader = ROM16(entry[10]) * 1000;
+                        perflvl->memory = ROM16(entry[12]) * 1000;
                         /*XXX: confirm on 0x35 */
-                        perflvl->unk05 = ROM16(entry[16]);
+                        perflvl->unk05 = ROM16(entry[16]) * 1000;
                         break;
                 case 0x40:
 #define subent(n) entry[perf[2] + ((n) * perf[3])]
                         perflvl->fanspeed = 0; /*XXX*/
                         perflvl->voltage = 0; /*XXX: entry[2] */;
-                        perflvl->core = ROM16(subent(0)) & 0xfff;
-                        perflvl->shader = ROM16(subent(1)) & 0xfff;
-                        perflvl->memory = ROM16(subent(2)) & 0xfff;
+                        perflvl->core = (ROM16(subent(0)) & 0xfff) * 1000;
+                        perflvl->shader = (ROM16(subent(1)) & 0xfff) * 1000;
+                        perflvl->memory = (ROM16(subent(2)) & 0xfff) * 1000;
                         break;
                 }
 
-                /* convert MHz -> KHz, it's more convenient */
-                perflvl->core *= 1000;
-                perflvl->memory *= 1000;
-                perflvl->shader *= 1000;
-                perflvl->unk05 *= 1000;
-
                 /* make sure vid is valid */
                 if (pm->voltage.supported && perflvl->voltage) {
                         vid = nouveau_volt_vid_lookup(dev, perflvl->voltage);