egl: Convert configs to use shifts and sizes instead of masks

Change dri2_add_config to take arrays of shifts and sizes, and compare with
those set in the dri config. Convert all platform driver masks
to shifts and sizes.

In order to handle older drivers, where shift attributes aren't available,
we fall back to the mask attributes and compute the shifts with ffs.

Signed-off-by: Kevin Strasser <[email protected]>
Reviewed-by: Emil Velikov <[email protected]>

8 files changed, 178 insertions, 86 deletions

diff --git a/src/egl/drivers/dri2/egl_dri2.c b/src/egl/drivers/dri2/egl_dri2.c
index 8dd1890ee07..56ebcb7c403 100644
--- a/src/egl/drivers/dri2/egl_dri2.c
+++ b/src/egl/drivers/dri2/egl_dri2.c
@@ -175,11 +175,7 @@ const __DRIswrastLoaderExtension swrast_pbuffer_loader_extension = {
 static const EGLint dri2_to_egl_attribute_map[__DRI_ATTRIB_MAX] = {
    [__DRI_ATTRIB_BUFFER_SIZE ]          = EGL_BUFFER_SIZE,
    [__DRI_ATTRIB_LEVEL]                 = EGL_LEVEL,
-   [__DRI_ATTRIB_RED_SIZE]              = EGL_RED_SIZE,
-   [__DRI_ATTRIB_GREEN_SIZE]            = EGL_GREEN_SIZE,
-   [__DRI_ATTRIB_BLUE_SIZE]             = EGL_BLUE_SIZE,
    [__DRI_ATTRIB_LUMINANCE_SIZE]        = EGL_LUMINANCE_SIZE,
-   [__DRI_ATTRIB_ALPHA_SIZE]            = EGL_ALPHA_SIZE,
    [__DRI_ATTRIB_DEPTH_SIZE]            = EGL_DEPTH_SIZE,
    [__DRI_ATTRIB_STENCIL_SIZE]          = EGL_STENCIL_SIZE,
    [__DRI_ATTRIB_SAMPLE_BUFFERS]        = EGL_SAMPLE_BUFFERS,
@@ -214,10 +210,39 @@ dri2_match_config(const _EGLConfig *conf, const _EGLConfig *criteria)
    return EGL_TRUE;
 }
 
+void
+dri2_get_shifts_and_sizes(const __DRIcoreExtension *core,
+                          const __DRIconfig *config, int *shifts,
+		          unsigned int *sizes)
+{
+   unsigned int mask;
+
+   if (core->getConfigAttrib(config, __DRI_ATTRIB_RED_SHIFT, (unsigned int *)&shifts[0])) {
+      core->getConfigAttrib(config, __DRI_ATTRIB_GREEN_SHIFT, (unsigned int *)&shifts[1]);
+      core->getConfigAttrib(config, __DRI_ATTRIB_BLUE_SHIFT, (unsigned int *)&shifts[2]);
+      core->getConfigAttrib(config, __DRI_ATTRIB_ALPHA_SHIFT, (unsigned int *)&shifts[3]);
+   } else {
+      /* Driver isn't exposing shifts, so convert masks to shifts */
+      core->getConfigAttrib(config, __DRI_ATTRIB_RED_MASK, &mask);
+      shifts[0] = ffs(mask) - 1;
+      core->getConfigAttrib(config, __DRI_ATTRIB_GREEN_MASK, &mask);
+      shifts[1] = ffs(mask) - 1;
+      core->getConfigAttrib(config, __DRI_ATTRIB_BLUE_MASK, &mask);
+      shifts[2] = ffs(mask) - 1;
+      core->getConfigAttrib(config, __DRI_ATTRIB_ALPHA_MASK, &mask);
+      shifts[3] = ffs(mask) - 1;
+   }
+
+   core->getConfigAttrib(config, __DRI_ATTRIB_RED_SIZE, &sizes[0]);
+   core->getConfigAttrib(config, __DRI_ATTRIB_GREEN_SIZE, &sizes[1]);
+   core->getConfigAttrib(config, __DRI_ATTRIB_BLUE_SIZE, &sizes[2]);
+   core->getConfigAttrib(config, __DRI_ATTRIB_ALPHA_SIZE, &sizes[3]);
+}
+
 struct dri2_egl_config *
 dri2_add_config(_EGLDisplay *disp, const __DRIconfig *dri_config, int id,
                 EGLint surface_type, const EGLint *attr_list,
-                const unsigned int *rgba_masks)
+                const int *rgba_shifts, const unsigned int *rgba_sizes)
 {
    struct dri2_egl_config *conf;
    struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
@@ -225,7 +250,8 @@ dri2_add_config(_EGLDisplay *disp, const __DRIconfig *dri_config, int id,
    unsigned int attrib, value, double_buffer;
    bool srgb = false;
    EGLint key, bind_to_texture_rgb, bind_to_texture_rgba;
-   unsigned int dri_masks[4] = { 0, 0, 0, 0 };
+   int dri_shifts[4] = { -1, -1, -1, -1 };
+   unsigned int dri_sizes[4] = { 0, 0, 0, 0 };
    _EGLConfig *matching_config;
    EGLint num_configs = 0;
    EGLint config_id;
@@ -273,20 +299,56 @@ dri2_add_config(_EGLDisplay *disp, const __DRIconfig *dri_config, int id,
          double_buffer = value;
          break;
 
+      case __DRI_ATTRIB_RED_SIZE:
+         dri_sizes[0] = value;
+         _eglSetConfigKey(&base, EGL_RED_SIZE, value);
+         break;
+
       case __DRI_ATTRIB_RED_MASK:
-         dri_masks[0] = value;
+         dri_shifts[0] = ffs(value) - 1;
+         break;
+
+      case __DRI_ATTRIB_RED_SHIFT:
+         dri_shifts[0] = value;
+         break;
+
+      case __DRI_ATTRIB_GREEN_SIZE:
+         dri_sizes[1] = value;
+         _eglSetConfigKey(&base, EGL_GREEN_SIZE, value);
          break;
 
       case __DRI_ATTRIB_GREEN_MASK:
-         dri_masks[1] = value;
+         dri_shifts[1] = ffs(value) - 1;
+         break;
+
+      case __DRI_ATTRIB_GREEN_SHIFT:
+         dri_shifts[1] = value;
+         break;
+
+      case __DRI_ATTRIB_BLUE_SIZE:
+         dri_sizes[2] = value;
+         _eglSetConfigKey(&base, EGL_BLUE_SIZE, value);
          break;
 
       case __DRI_ATTRIB_BLUE_MASK:
-         dri_masks[2] = value;
+         dri_shifts[2] = ffs(value) - 1;
+         break;
+
+      case __DRI_ATTRIB_BLUE_SHIFT:
+         dri_shifts[2] = value;
+         break;
+
+     case __DRI_ATTRIB_ALPHA_SIZE:
+         dri_sizes[3] = value;
+         _eglSetConfigKey(&base, EGL_ALPHA_SIZE, value);
          break;
 
       case __DRI_ATTRIB_ALPHA_MASK:
-         dri_masks[3] = value;
+         dri_shifts[3] = ffs(value) - 1;
+         break;
+
+      case __DRI_ATTRIB_ALPHA_SHIFT:
+         dri_shifts[3] = value;
          break;
 
       case __DRI_ATTRIB_ACCUM_RED_SIZE:
@@ -328,7 +390,10 @@ dri2_add_config(_EGLDisplay *disp, const __DRIconfig *dri_config, int id,
       for (int i = 0; attr_list[i] != EGL_NONE; i += 2)
          _eglSetConfigKey(&base, attr_list[i], attr_list[i+1]);
 
-   if (rgba_masks && memcmp(rgba_masks, dri_masks, sizeof(dri_masks)))
+   if (rgba_shifts && memcmp(rgba_shifts, dri_shifts, sizeof(dri_shifts)))
+      return NULL;
+
+   if (rgba_sizes && memcmp(rgba_sizes, dri_sizes, sizeof(dri_sizes)))
       return NULL;
 
    base.NativeRenderable = EGL_TRUE;
diff --git a/src/egl/drivers/dri2/egl_dri2.h b/src/egl/drivers/dri2/egl_dri2.h
index bb3352f1b69..5a148f12118 100644
--- a/src/egl/drivers/dri2/egl_dri2.h
+++ b/src/egl/drivers/dri2/egl_dri2.h
@@ -404,10 +404,15 @@ dri2_surface_get_dri_drawable(_EGLSurface *surf);
 __DRIimage *
 dri2_lookup_egl_image(__DRIscreen *screen, void *image, void *data);
 
+void
+dri2_get_shifts_and_sizes(const __DRIcoreExtension *core,
+		          const __DRIconfig *config, int *shifts,
+			  unsigned int *sizes);
+
 struct dri2_egl_config *
 dri2_add_config(_EGLDisplay *disp, const __DRIconfig *dri_config, int id,
                 EGLint surface_type, const EGLint *attr_list,
-                const unsigned int *rgba_masks);
+                const int *rgba_shifts, const unsigned int *rgba_sizes);
 
 _EGLImage *
 dri2_create_image_khr(_EGLDriver *drv, _EGLDisplay *disp,
diff --git a/src/egl/drivers/dri2/platform_android.c b/src/egl/drivers/dri2/platform_android.c
index dda38d67265..601b29e1d84 100644
--- a/src/egl/drivers/dri2/platform_android.c
+++ b/src/egl/drivers/dri2/platform_android.c
@@ -1151,12 +1151,13 @@ droid_add_configs_for_visuals(_EGLDriver *drv, _EGLDisplay *disp)
    struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
    static const struct {
       int format;
-      unsigned int rgba_masks[4];
+      int rgba_shifts[4];
+      unsigned int rgba_sizes[4];
    } visuals[] = {
-      { HAL_PIXEL_FORMAT_RGBA_8888, { 0x000000ff, 0x0000ff00, 0x00ff0000, 0xff000000 } },
-      { HAL_PIXEL_FORMAT_RGBX_8888, { 0x000000ff, 0x0000ff00, 0x00ff0000, 0x00000000 } },
-      { HAL_PIXEL_FORMAT_RGB_565,   { 0x0000f800, 0x000007e0, 0x0000001f, 0x00000000 } },
-      { HAL_PIXEL_FORMAT_BGRA_8888, { 0x00ff0000, 0x0000ff00, 0x000000ff, 0xff000000 } },
+      { HAL_PIXEL_FORMAT_RGBA_8888, { 0, 8, 16, 24 }, { 8, 8, 8, 8 } },
+      { HAL_PIXEL_FORMAT_RGBX_8888, { 0, 8, 16, -1 }, { 8, 8, 8, 0 } },
+      { HAL_PIXEL_FORMAT_RGB_565,   { 11, 5, 0, -1 }, { 5, 6, 5, 0 } },
+      { HAL_PIXEL_FORMAT_BGRA_8888, { 16, 8, 0, 24 }, { 8, 8, 8, 8 } },
    };
 
    unsigned int format_count[ARRAY_SIZE(visuals)] = { 0 };
@@ -1195,7 +1196,7 @@ droid_add_configs_for_visuals(_EGLDriver *drv, _EGLDisplay *disp)
          struct dri2_egl_config *dri2_conf =
             dri2_add_config(disp, dri2_dpy->driver_configs[j],
                             config_count + 1, surface_type, config_attrs,
-                            visuals[i].rgba_masks);
+                            visuals[i].rgba_shifts, visuals[i].rgba_sizes);
          if (dri2_conf) {
             if (dri2_conf->base.ConfigID == config_count + 1)
                config_count++;
diff --git a/src/egl/drivers/dri2/platform_device.c b/src/egl/drivers/dri2/platform_device.c
index a73ea415396..9d3dbd5857f 100644
--- a/src/egl/drivers/dri2/platform_device.c
+++ b/src/egl/drivers/dri2/platform_device.c
@@ -188,11 +188,12 @@ device_add_configs_for_visuals(_EGLDriver *drv, _EGLDisplay *disp)
    struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
    static const struct {
       const char *format_name;
-      unsigned int rgba_masks[4];
+      int rgba_shifts[4];
+      unsigned int rgba_sizes[4];
    } visuals[] = {
-      { "ARGB8888", { 0xff0000, 0xff00, 0xff, 0xff000000 } },
-      { "RGB888",   { 0xff0000, 0xff00, 0xff, 0x0 } },
-      { "RGB565",   { 0x00f800, 0x07e0, 0x1f, 0x0 } },
+      { "ARGB8888", { 16, 8, 0, 24 }, { 8, 8, 8, 8 } },
+      { "RGB888",   { 16, 8, 0, -1 }, { 8, 8, 8, 0 } },
+      { "RGB565",   { 11, 5, 0, -1 }, { 5, 6, 5, 0 } },
    };
    unsigned int format_count[ARRAY_SIZE(visuals)] = { 0 };
    unsigned int config_count = 0;
@@ -203,7 +204,7 @@ device_add_configs_for_visuals(_EGLDriver *drv, _EGLDisplay *disp)
 
          dri2_conf = dri2_add_config(disp, dri2_dpy->driver_configs[i],
                config_count + 1, EGL_PBUFFER_BIT, NULL,
-               visuals[j].rgba_masks);
+               visuals[j].rgba_shifts, visuals[j].rgba_sizes);
 
          if (dri2_conf) {
             if (dri2_conf->base.ConfigID == config_count + 1)
diff --git a/src/egl/drivers/dri2/platform_drm.c b/src/egl/drivers/dri2/platform_drm.c
index 648bc86ade7..56b8e59d2c5 100644
--- a/src/egl/drivers/dri2/platform_drm.c
+++ b/src/egl/drivers/dri2/platform_drm.c
@@ -96,7 +96,8 @@ dri2_drm_config_is_compatible(struct dri2_egl_display *dri2_dpy,
                               struct gbm_surface *surface)
 {
    const struct gbm_dri_visual *visual = NULL;
-   unsigned int red, green, blue, alpha;
+   int shifts[4];
+   unsigned int sizes[4];
    int i;
 
    /* Check that the EGLConfig being used to render to the surface is
@@ -104,10 +105,7 @@ dri2_drm_config_is_compatible(struct dri2_egl_display *dri2_dpy,
     * otherwise-compatible formats is relatively common, explicitly allow
     * this.
     */
-   dri2_dpy->core->getConfigAttrib(config, __DRI_ATTRIB_RED_MASK, &red);
-   dri2_dpy->core->getConfigAttrib(config, __DRI_ATTRIB_GREEN_MASK, &green);
-   dri2_dpy->core->getConfigAttrib(config, __DRI_ATTRIB_BLUE_MASK, &blue);
-   dri2_dpy->core->getConfigAttrib(config, __DRI_ATTRIB_ALPHA_MASK, &alpha);
+   dri2_get_shifts_and_sizes(dri2_dpy->core, config, shifts, sizes);
 
    for (i = 0; i < dri2_dpy->gbm_dri->num_visuals; i++) {
       visual = &dri2_dpy->gbm_dri->visual_table[i];
@@ -118,10 +116,14 @@ dri2_drm_config_is_compatible(struct dri2_egl_display *dri2_dpy,
    if (i == dri2_dpy->gbm_dri->num_visuals)
       return false;
 
-   if (red != visual->rgba_masks.red ||
-       green != visual->rgba_masks.green ||
-       blue != visual->rgba_masks.blue ||
-       (alpha && visual->rgba_masks.alpha && alpha != visual->rgba_masks.alpha)) {
+   if (shifts[0] != visual->rgba_shifts.red ||
+       shifts[1] != visual->rgba_shifts.green ||
+       shifts[2] != visual->rgba_shifts.blue ||
+       (shifts[3] > -1 && shifts[3] != visual->rgba_shifts.alpha) ||
+       sizes[0] != visual->rgba_sizes.red ||
+       sizes[1] != visual->rgba_sizes.green ||
+       sizes[2] != visual->rgba_sizes.blue ||
+       (sizes[3] > 0 && sizes[3] != visual->rgba_sizes.alpha)) {
       return false;
    }
 
@@ -612,24 +614,23 @@ drm_add_configs_for_visuals(_EGLDriver *drv, _EGLDisplay *disp)
    memset(format_count, 0, num_visuals * sizeof(unsigned int));
 
    for (unsigned i = 0; dri2_dpy->driver_configs[i]; i++) {
-      unsigned int red, green, blue, alpha;
+      const __DRIconfig *config = dri2_dpy->driver_configs[i];
+      int shifts[4];
+      unsigned int sizes[4];
 
-      dri2_dpy->core->getConfigAttrib(dri2_dpy->driver_configs[i],
-                                      __DRI_ATTRIB_RED_MASK, &red);
-      dri2_dpy->core->getConfigAttrib(dri2_dpy->driver_configs[i],
-                                      __DRI_ATTRIB_GREEN_MASK, &green);
-      dri2_dpy->core->getConfigAttrib(dri2_dpy->driver_configs[i],
-                                      __DRI_ATTRIB_BLUE_MASK, &blue);
-      dri2_dpy->core->getConfigAttrib(dri2_dpy->driver_configs[i],
-                                      __DRI_ATTRIB_ALPHA_MASK, &alpha);
+      dri2_get_shifts_and_sizes(dri2_dpy->core, config, shifts, sizes);
 
       for (unsigned j = 0; j < num_visuals; j++) {
          struct dri2_egl_config *dri2_conf;
 
-         if (visuals[j].rgba_masks.red != red ||
-             visuals[j].rgba_masks.green != green ||
-             visuals[j].rgba_masks.blue != blue ||
-             visuals[j].rgba_masks.alpha != alpha)
+         if (visuals[j].rgba_shifts.red != shifts[0] ||
+             visuals[j].rgba_shifts.green != shifts[1] ||
+             visuals[j].rgba_shifts.blue != shifts[2] ||
+             visuals[j].rgba_shifts.alpha != shifts[3] ||
+             visuals[j].rgba_sizes.red != sizes[0] ||
+             visuals[j].rgba_sizes.green != sizes[1] ||
+             visuals[j].rgba_sizes.blue != sizes[2] ||
+             visuals[j].rgba_sizes.alpha != sizes[3])
             continue;
 
          const EGLint attr_list[] = {
@@ -638,7 +639,7 @@ drm_add_configs_for_visuals(_EGLDriver *drv, _EGLDisplay *disp)
          };
 
          dri2_conf = dri2_add_config(disp, dri2_dpy->driver_configs[i],
-               config_count + 1, EGL_WINDOW_BIT, attr_list, NULL);
+               config_count + 1, EGL_WINDOW_BIT, attr_list, NULL, NULL);
          if (dri2_conf) {
             if (dri2_conf->base.ConfigID == config_count + 1)
                config_count++;
diff --git a/src/egl/drivers/dri2/platform_surfaceless.c b/src/egl/drivers/dri2/platform_surfaceless.c
index 8eeb2d4ed43..13695a08765 100644
--- a/src/egl/drivers/dri2/platform_surfaceless.c
+++ b/src/egl/drivers/dri2/platform_surfaceless.c
@@ -182,11 +182,12 @@ surfaceless_add_configs_for_visuals(_EGLDriver *drv, _EGLDisplay *disp)
    struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
    static const struct {
       const char *format_name;
-      unsigned int rgba_masks[4];
+      int rgba_shifts[4];
+      unsigned int rgba_sizes[4];
    } visuals[] = {
-      { "ARGB8888", { 0xff0000, 0xff00, 0xff, 0xff000000 } },
-      { "RGB888",   { 0xff0000, 0xff00, 0xff, 0x0 } },
-      { "RGB565",   { 0x00f800, 0x07e0, 0x1f, 0x0 } },
+      { "ARGB8888", { 16, 8, 0, 24 }, { 8, 8, 8, 8 } },
+      { "RGB888",   { 16, 8, 0, -1 }, { 8, 8, 8, 0 } },
+      { "RGB565",   { 11, 5, 0, -1 }, { 5, 6, 5, 0 } },
    };
    unsigned int format_count[ARRAY_SIZE(visuals)] = { 0 };
    unsigned int config_count = 0;
@@ -197,7 +198,7 @@ surfaceless_add_configs_for_visuals(_EGLDriver *drv, _EGLDisplay *disp)
 
          dri2_conf = dri2_add_config(disp, dri2_dpy->driver_configs[i],
                config_count + 1, EGL_PBUFFER_BIT, NULL,
-               visuals[j].rgba_masks);
+               visuals[j].rgba_shifts, visuals[j].rgba_sizes);
 
          if (dri2_conf) {
             if (dri2_conf->base.ConfigID == config_count + 1)
diff --git a/src/egl/drivers/dri2/platform_wayland.c b/src/egl/drivers/dri2/platform_wayland.c
index 70a7bef9b11..6f538835617 100644
--- a/src/egl/drivers/dri2/platform_wayland.c
+++ b/src/egl/drivers/dri2/platform_wayland.c
@@ -69,49 +69,57 @@ static const struct dri2_wl_visual {
     */
    int alt_dri_image_format;
    int bpp;
-   unsigned int rgba_masks[4];
+   int rgba_shifts[4];
+   unsigned int rgba_sizes[4];
 } dri2_wl_visuals[] = {
    {
      "XRGB2101010",
      WL_DRM_FORMAT_XRGB2101010, WL_SHM_FORMAT_XRGB2101010,
      __DRI_IMAGE_FORMAT_XRGB2101010, __DRI_IMAGE_FORMAT_XBGR2101010, 32,
-     { 0x3ff00000, 0x000ffc00, 0x000003ff, 0x00000000 }
+     { 20, 10, 0, -1 },
+     { 10, 10, 10, 0 },
    },
    {
      "ARGB2101010",
      WL_DRM_FORMAT_ARGB2101010, WL_SHM_FORMAT_ARGB2101010,
      __DRI_IMAGE_FORMAT_ARGB2101010, __DRI_IMAGE_FORMAT_ABGR2101010, 32,
-     { 0x3ff00000, 0x000ffc00, 0x000003ff, 0xc0000000 }
+     { 20, 10, 0, 30 },
+     { 10, 10, 10, 2 },
    },
    {
      "XBGR2101010",
      WL_DRM_FORMAT_XBGR2101010, WL_SHM_FORMAT_XBGR2101010,
      __DRI_IMAGE_FORMAT_XBGR2101010, __DRI_IMAGE_FORMAT_XRGB2101010, 32,
-     { 0x000003ff, 0x000ffc00, 0x3ff00000, 0x00000000 }
+     { 0, 10, 20, -1 },
+     { 10, 10, 10, 0 },
    },
    {
      "ABGR2101010",
      WL_DRM_FORMAT_ABGR2101010, WL_SHM_FORMAT_ABGR2101010,
      __DRI_IMAGE_FORMAT_ABGR2101010, __DRI_IMAGE_FORMAT_ARGB2101010, 32,
-     { 0x000003ff, 0x000ffc00, 0x3ff00000, 0xc0000000 }
+     { 0, 10, 20, 30 },
+     { 10, 10, 10, 2 },
    },
    {
      "XRGB8888",
      WL_DRM_FORMAT_XRGB8888, WL_SHM_FORMAT_XRGB8888,
      __DRI_IMAGE_FORMAT_XRGB8888, __DRI_IMAGE_FORMAT_NONE, 32,
-     { 0x00ff0000, 0x0000ff00, 0x000000ff, 0x00000000 }
+     { 16, 8, 0, -1 },
+     { 8, 8, 8, 0 },
    },
    {
      "ARGB8888",
      WL_DRM_FORMAT_ARGB8888, WL_SHM_FORMAT_ARGB8888,
      __DRI_IMAGE_FORMAT_ARGB8888, __DRI_IMAGE_FORMAT_NONE, 32,
-     { 0x00ff0000, 0x0000ff00, 0x000000ff, 0xff000000 }
+     { 16, 8, 0, 24 },
+     { 8, 8, 8, 8 },
    },
    {
      "RGB565",
      WL_DRM_FORMAT_RGB565, WL_SHM_FORMAT_RGB565,
      __DRI_IMAGE_FORMAT_RGB565, __DRI_IMAGE_FORMAT_NONE, 16,
-     { 0xf800, 0x07e0, 0x001f, 0x0000 }
+     { 11, 5, 0, -1 },
+     { 5, 6, 5, 0 },
    },
 };
 
@@ -123,20 +131,22 @@ static int
 dri2_wl_visual_idx_from_config(struct dri2_egl_display *dri2_dpy,
                                const __DRIconfig *config)
 {
-   unsigned int red, green, blue, alpha;
+   int shifts[4];
+   unsigned int sizes[4];
 
-   dri2_dpy->core->getConfigAttrib(config, __DRI_ATTRIB_RED_MASK, &red);
-   dri2_dpy->core->getConfigAttrib(config, __DRI_ATTRIB_GREEN_MASK, &green);
-   dri2_dpy->core->getConfigAttrib(config, __DRI_ATTRIB_BLUE_MASK, &blue);
-   dri2_dpy->core->getConfigAttrib(config, __DRI_ATTRIB_ALPHA_MASK, &alpha);
+   dri2_get_shifts_and_sizes(dri2_dpy->core, config, shifts, sizes);
 
    for (unsigned int i = 0; i < ARRAY_SIZE(dri2_wl_visuals); i++) {
       const struct dri2_wl_visual *wl_visual = &dri2_wl_visuals[i];
 
-      if (red == wl_visual->rgba_masks[0] &&
-          green == wl_visual->rgba_masks[1] &&
-          blue == wl_visual->rgba_masks[2] &&
-          alpha == wl_visual->rgba_masks[3]) {
+      if (shifts[0] == wl_visual->rgba_shifts[0] &&
+          shifts[1] == wl_visual->rgba_shifts[1] &&
+          shifts[2] == wl_visual->rgba_shifts[2] &&
+          shifts[3] == wl_visual->rgba_shifts[3] &&
+          sizes[0] == wl_visual->rgba_sizes[0] &&
+          sizes[1] == wl_visual->rgba_sizes[1] &&
+          sizes[2] == wl_visual->rgba_sizes[2] &&
+          sizes[3] == wl_visual->rgba_sizes[3]) {
          return i;
       }
    }
@@ -1354,7 +1364,7 @@ dri2_wl_add_configs_for_visuals(_EGLDriver *drv, _EGLDisplay *disp)
             continue;
 
          dri2_conf = dri2_add_config(disp, dri2_dpy->driver_configs[i],
-               count + 1, EGL_WINDOW_BIT, NULL, dri2_wl_visuals[j].rgba_masks);
+               count + 1, EGL_WINDOW_BIT, NULL, dri2_wl_visuals[j].rgba_shifts, dri2_wl_visuals[j].rgba_sizes);
          if (dri2_conf) {
             if (dri2_conf->base.ConfigID == count + 1)
                count++;
@@ -1387,7 +1397,8 @@ dri2_wl_add_configs_for_visuals(_EGLDriver *drv, _EGLDisplay *disp)
           */
          dri2_conf = dri2_add_config(disp, dri2_dpy->driver_configs[i],
                                      count + 1, EGL_WINDOW_BIT, NULL,
-                                     dri2_wl_visuals[c].rgba_masks);
+                                     dri2_wl_visuals[c].rgba_shifts,
+                                     dri2_wl_visuals[c].rgba_sizes);
          if (dri2_conf) {
             if (dri2_conf->base.ConfigID == count + 1)
                count++;
diff --git a/src/egl/drivers/dri2/platform_x11.c b/src/egl/drivers/dri2/platform_x11.c
index 7a58e718492..0fa0442f4af 100644
--- a/src/egl/drivers/dri2/platform_x11.c
+++ b/src/egl/drivers/dri2/platform_x11.c
@@ -42,6 +42,7 @@
 #include <sys/stat.h>
 #include "util/debug.h"
 #include "util/macros.h"
+#include "util/bitscan.h"
 
 #include "egl_dri2.h"
 #include "egl_dri2_fallbacks.h"
@@ -846,16 +847,23 @@ dri2_x11_add_configs_for_visuals(struct dri2_egl_display *dri2_dpy,
                     EGL_NONE
             };
 
-            unsigned int rgba_masks[4] = {
-               visuals[i].red_mask,
-               visuals[i].green_mask,
-               visuals[i].blue_mask,
+            int rgba_shifts[4] = {
+               ffs(visuals[i].red_mask) - 1,
+               ffs(visuals[i].green_mask) - 1,
+               ffs(visuals[i].blue_mask) - 1,
+               -1,
+            };
+
+            unsigned int rgba_sizes[4] = {
+               util_bitcount(visuals[i].red_mask),
+               util_bitcount(visuals[i].green_mask),
+               util_bitcount(visuals[i].blue_mask),
                0,
             };
 
             dri2_conf = dri2_add_config(disp, config, config_count + 1,
                                         surface_type, config_attrs,
-                                        rgba_masks);
+                                        rgba_shifts, rgba_sizes);
             if (dri2_conf)
                if (dri2_conf->base.ConfigID == config_count + 1)
                   config_count++;
@@ -869,11 +877,14 @@ dri2_x11_add_configs_for_visuals(struct dri2_egl_display *dri2_dpy,
              * wants... especially on drivers that only have 32-bit RGBA
              * EGLConfigs! */
             if (d.data->depth == 24 || d.data->depth == 30) {
-               rgba_masks[3] =
-                  ~(rgba_masks[0] | rgba_masks[1] | rgba_masks[2]);
+               unsigned int rgba_mask = ~(visuals[i].red_mask |
+                                          visuals[i].green_mask |
+                                          visuals[i].blue_mask);
+               rgba_shifts[3] = ffs(rgba_mask) - 1;
+               rgba_sizes[3] = util_bitcount(rgba_mask);
                dri2_conf = dri2_add_config(disp, config, config_count + 1,
                                            surface_type, config_attrs,
-                                           rgba_masks);
+                                           rgba_shifts, rgba_sizes);
                if (dri2_conf)
                   if (dri2_conf->base.ConfigID == config_count + 1)
                      config_count++;
@@ -896,13 +907,9 @@ dri2_x11_add_configs_for_visuals(struct dri2_egl_display *dri2_dpy,
             EGL_NONE
          };
          EGLint surface_type = EGL_PBUFFER_BIT;
-         unsigned int rgba_masks[4] = {
-            0x1f << 11,
-            0x3f << 5,
-            0x1f << 0,
-            0,
-         };
-
+         int rgba_shifts[4] = { 11, 5, 0, -1 };
+         unsigned int rgba_sizes[4] = { 5, 6, 5, 0 };
+ 
          /* Check that we've found single-sample, no depth, no stencil,
           * and single-buffered.
           */
@@ -918,7 +925,7 @@ dri2_x11_add_configs_for_visuals(struct dri2_egl_display *dri2_dpy,
          }
 
          if (dri2_add_config(disp, config, config_count + 1, surface_type,
-                             config_attrs, rgba_masks)) {
+                             config_attrs, rgba_shifts, rgba_sizes)) {
             config_count++;
             break;
          }