modesetting: add "FallbackCursor" option

On many cards, SIZE_HINTS isn't implemented, so the hardware cursor used
is the fallback one.

With this, we allow the user to specify what size the hardware cursor should have,
instead of forcing 64x64.

Signed-off-by: stefan11111 <[email protected]>

Author: stefan11111

hw/xfree86/drivers/video/modesetting/driver.c

@@ -131,6 +131,7 @@ static SymTabRec Chipsets[] = {
 
 static const OptionInfoRec Options[] = {
     {OPTION_SW_CURSOR, "SWcursor", OPTV_BOOLEAN, {0}, FALSE},
+    {OPTION_FALLBACK_CURSOR, "FallbackCursor", OPTV_STRING, {0}, FALSE},
     {OPTION_DEVICE_PATH, "kmsdev", OPTV_STRING, {0}, FALSE},
     {OPTION_SHADOW_FB, "ShadowFB", OPTV_BOOLEAN, {0}, FALSE},
     {OPTION_ACCEL_METHOD, "AccelMethod", OPTV_STRING, {0}, FALSE},

hw/xfree86/drivers/video/modesetting/driver.h

@@ -54,6 +54,7 @@ struct ms_vrr_priv {
 
 typedef enum {
     OPTION_SW_CURSOR,
+    OPTION_FALLBACK_CURSOR,
     OPTION_DEVICE_PATH,
     OPTION_SHADOW_FB,
     OPTION_ACCEL_METHOD,

hw/xfree86/drivers/video/modesetting/drmmode_display.c

@@ -2785,8 +2785,63 @@ drmmode_crtc_vrr_init(int drm_fd, xf86CrtcPtr crtc)
     drmModeFreeObjectProperties(drm_props);
 }
 
+static drmmode_cursor_dim_rec
+drmmode_cursor_get_fallback(drmmode_ptr drmmode)
+{
+    drmmode_cursor_dim_rec fallback;
+
+    const char *fallback_cursor_str = xf86GetOptValString(drmmode->Options,
+                                                          OPTION_FALLBACK_CURSOR);
+
+    char *height;
+
+    if (!fallback_cursor_str) {
+        goto kms_default;
+    }
+
+    errno = 0;
+    fallback.width = strtol(fallback_cursor_str, &height, 10);
+    if (errno || fallback.width == 0) {
+        goto kms_default;
+    }
+
+    if (*height == '\0') {
+        /* we have a width, but don't have a height */
+        fallback.height = fallback.width;
+        return fallback;
+    }
+
+    fallback.height = strtol(height + 1, NULL, 10);
+    if (errno || fallback.height == 0) {
+        goto kms_default;
+    }
+
+    return fallback;
+kms_default:
+    /* This is the safest fallback value as
+     * it is the default value that KMS uses.  */
+    fallback = (drmmode_cursor_dim_rec){
+        .width  = 64,
+        .height = 64,
+    };
+
+#if 0 /* We could instead use the largest possible cursor, but that uses more power */
+    ret = drmGetCap(drmmode->fd, DRM_CAP_CURSOR_WIDTH, &value);
+    if (!ret) {
+        fallback.width = value;
+    }
+
+    ret = drmGetCap(drmmode->fd, DRM_CAP_CURSOR_HEIGHT, &value);
+    if (!ret) {
+        fallback.height = value;
+    }
+#endif
+
+    return fallback;
+}
+
 static unsigned int
-drmmode_crtc_init(ScrnInfoPtr pScrn, drmmode_ptr drmmode, drmModeResPtr mode_res, drmmode_cursor_dim_rec fallback, int num)
+drmmode_crtc_init(ScrnInfoPtr pScrn, drmmode_ptr drmmode, drmModeResPtr mode_res, int num)
 {
     xf86CrtcPtr crtc;
     drmmode_crtc_private_ptr drmmode_crtc;
@@ -2817,8 +2872,7 @@ drmmode_crtc_init(ScrnInfoPtr pScrn, drmmode_ptr drmmode, drmModeResPtr mode_res
     drmmode_crtc->cursor.num_dimensions = 1;
     drmmode_crtc->cursor.dimensions = xnfalloc(sizeof(drmmode_cursor_dim_rec));
 
-    drmmode_crtc->cursor.dimensions[0].width = fallback.width;
-    drmmode_crtc->cursor.dimensions[0].height = fallback.height;
+    drmmode_crtc->cursor.dimensions[0] = drmmode_cursor_get_fallback(drmmode);
 
     props = drmModeObjectGetProperties(drmmode->fd, mode_res->crtcs[num],
                                        DRM_MODE_OBJECT_CRTC);
@@ -4143,31 +4197,12 @@ drmmode_pre_init(ScrnInfoPtr pScrn, drmmode_ptr drmmode, int cpp)
     xf86DrvMsgVerb(pScrn->scrnIndex, X_INFO, MS_LOGLEVEL_DEBUG,
                    "Up to %d crtcs needed for screen.\n", crtcs_needed);
 
-    /* This is the safest fallback value as
-     * it is the default value that KMS uses.  */
-    drmmode_cursor_dim_rec fallback = {
-        .width  = 64,
-        .height = 64,
-    };
-
-#if 0 /* We could instead use the largest possible cursor, but that uses more power */
-    ret = drmGetCap(drmmode->fd, DRM_CAP_CURSOR_WIDTH, &value);
-    if (!ret) {
-        fallback.width = value;
-    }
-
-    ret = drmGetCap(drmmode->fd, DRM_CAP_CURSOR_HEIGHT, &value);
-    if (!ret) {
-        fallback.height = value;
-    }
-#endif
-
     xf86CrtcSetSizeRange(pScrn, 320, 200, mode_res->max_width,
                          mode_res->max_height);
     for (i = 0; i < mode_res->count_crtcs; i++)
         if (!xf86IsEntityShared(pScrn->entityList[0]) ||
             (crtcs_needed && !(ms_ent->assigned_crtcs & (1 << i))))
-            crtcs_needed -= drmmode_crtc_init(pScrn, drmmode, mode_res, fallback, i);
+            crtcs_needed -= drmmode_crtc_init(pScrn, drmmode, mode_res, i);
 
     /* All ZaphodHeads outputs provided with matching crtcs? */
     if (xf86IsEntityShared(pScrn->entityList[0]) && (crtcs_needed > 0))

hw/xfree86/drivers/video/modesetting/modesetting.man

@@ -49,6 +49,10 @@ are supported:
 Selects software cursor.  The default is
 .B off.
 .TP
+.BI "Option \*qFallbackCursor\*q \*q" string \*q
+The size of the cursor to use if SIZE_HINTS isn't available.
+The default is "64x64".
+.TP
 .BI "Option \*qkmsdev\*q \*q" string \*q
 The framebuffer device to use. Default: /dev/dri/card0.
 .TP