drm/mgag200: Split up connector's mode_valid helper

Split up the connector's mode_valid helper into a simple-pipe and a
mode-config helper. The simple-pipe helper tests for display-size
limits while the mode-config helper tests for memory-bandwidth limits.

Also add the mgag200_ prefix to mga_vga_calculate_mode_bandwidth() and
comment on the function's purpose.

The memory-bandwidth tests assume that the display uses 4 bytes per
pixel. The first models of G200SE-A only had 1.75 MiB of VRAM, which
limits these devices to 640x480-32.

v2:
	* note the memory constraints on early G200SE-A

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Tested-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220516134343.6085-8-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c
index a718a20b3a2003a0d1830611c2fb83b9a7f684d9..028c6ba7124c56fc55daa3bc1d9cc5c1489c88f2 100644 (file)
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -705,38 +705,27 @@ static int mgag200_vga_connector_helper_get_modes(struct drm_connector *connecto
        return ret;
 }
 
-static uint32_t mga_vga_calculate_mode_bandwidth(struct drm_display_mode *mode,
-                                                       int bits_per_pixel)
-{
-       uint32_t total_area, divisor;
-       uint64_t active_area, pixels_per_second, bandwidth;
-       uint64_t bytes_per_pixel = (bits_per_pixel + 7) / 8;
-
-       divisor = 1024;
-
-       if (!mode->htotal || !mode->vtotal || !mode->clock)
-               return 0;
-
-       active_area = mode->hdisplay * mode->vdisplay;
-       total_area = mode->htotal * mode->vtotal;
-
-       pixels_per_second = active_area * mode->clock * 1000;
-       do_div(pixels_per_second, total_area);
-
-       bandwidth = pixels_per_second * bytes_per_pixel * 100;
-       do_div(bandwidth, divisor);
+static const struct drm_connector_helper_funcs mga_vga_connector_helper_funcs = {
+       .get_modes  = mgag200_vga_connector_helper_get_modes,
+};
 
-       return (uint32_t)(bandwidth);
-}
+static const struct drm_connector_funcs mga_vga_connector_funcs = {
+       .reset                  = drm_atomic_helper_connector_reset,
+       .fill_modes             = drm_helper_probe_single_connector_modes,
+       .destroy                = drm_connector_cleanup,
+       .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+       .atomic_destroy_state   = drm_atomic_helper_connector_destroy_state,
+};
 
-#define MODE_BANDWIDTH MODE_BAD
+/*
+ * Simple Display Pipe
+ */
 
-static enum drm_mode_status mga_vga_mode_valid(struct drm_connector *connector,
-                                struct drm_display_mode *mode)
+static enum drm_mode_status
+mgag200_simple_display_pipe_mode_valid(struct drm_simple_display_pipe *pipe,
+                                      const struct drm_display_mode *mode)
 {
-       struct drm_device *dev = connector->dev;
-       struct mga_device *mdev = to_mga_device(dev);
-       int bpp = 32;
+       struct mga_device *mdev = to_mga_device(pipe->crtc.dev);
 
        if (IS_G200_SE(mdev)) {
                u32 unique_rev_id = mdev->model.g200se.unique_rev_id;
@@ -746,42 +735,17 @@ static enum drm_mode_status mga_vga_mode_valid(struct drm_connector *connector,
                                return MODE_VIRTUAL_X;
                        if (mode->vdisplay > 1200)
                                return MODE_VIRTUAL_Y;
-                       if (mga_vga_calculate_mode_bandwidth(mode, bpp)
-                               > (24400 * 1024))
-                               return MODE_BANDWIDTH;
                } else if (unique_rev_id == 0x02) {
                        if (mode->hdisplay > 1920)
                                return MODE_VIRTUAL_X;
                        if (mode->vdisplay > 1200)
                                return MODE_VIRTUAL_Y;
-                       if (mga_vga_calculate_mode_bandwidth(mode, bpp)
-                               > (30100 * 1024))
-                               return MODE_BANDWIDTH;
-               } else {
-                       if (mga_vga_calculate_mode_bandwidth(mode, bpp)
-                               > (55000 * 1024))
-                               return MODE_BANDWIDTH;
                }
        } else if (mdev->type == G200_WB) {
                if (mode->hdisplay > 1280)
                        return MODE_VIRTUAL_X;
                if (mode->vdisplay > 1024)
                        return MODE_VIRTUAL_Y;
-               if (mga_vga_calculate_mode_bandwidth(mode, bpp) >
-                   (31877 * 1024))
-                       return MODE_BANDWIDTH;
-       } else if (mdev->type == G200_EV &&
-               (mga_vga_calculate_mode_bandwidth(mode, bpp)
-                       > (32700 * 1024))) {
-               return MODE_BANDWIDTH;
-       } else if (mdev->type == G200_EH &&
-               (mga_vga_calculate_mode_bandwidth(mode, bpp)
-                       > (37500 * 1024))) {
-               return MODE_BANDWIDTH;
-       } else if (mdev->type == G200_ER &&
-               (mga_vga_calculate_mode_bandwidth(mode,
-                       bpp) > (55000 * 1024))) {
-               return MODE_BANDWIDTH;
        }
 
        if ((mode->hdisplay % 8) != 0 || (mode->hsync_start % 8) != 0 ||
@@ -799,30 +763,6 @@ static enum drm_mode_status mga_vga_mode_valid(struct drm_connector *connector,
        return MODE_OK;
 }
 
-static const struct drm_connector_helper_funcs mga_vga_connector_helper_funcs = {
-       .get_modes  = mgag200_vga_connector_helper_get_modes,
-       .mode_valid = mga_vga_mode_valid,
-};
-
-static const struct drm_connector_funcs mga_vga_connector_funcs = {
-       .reset                  = drm_atomic_helper_connector_reset,
-       .fill_modes             = drm_helper_probe_single_connector_modes,
-       .destroy                = drm_connector_cleanup,
-       .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
-       .atomic_destroy_state   = drm_atomic_helper_connector_destroy_state,
-};
-
-/*
- * Simple Display Pipe
- */
-
-static enum drm_mode_status
-mgag200_simple_display_pipe_mode_valid(struct drm_simple_display_pipe *pipe,
-                                      const struct drm_display_mode *mode)
-{
-       return MODE_OK;
-}
-
 static void
 mgag200_handle_damage(struct mga_device *mdev, struct drm_framebuffer *fb,
                      struct drm_rect *clip, const struct iosys_map *map)
@@ -1055,6 +995,31 @@ static const uint64_t mgag200_simple_display_pipe_fmtmods[] = {
  * Mode config
  */
 
+/* Calculates a mode's required memory bandwidth (in KiB/sec). */
+static uint32_t mgag200_calculate_mode_bandwidth(const struct drm_display_mode *mode,
+                                                unsigned int bits_per_pixel)
+{
+       uint32_t total_area, divisor;
+       uint64_t active_area, pixels_per_second, bandwidth;
+       uint64_t bytes_per_pixel = (bits_per_pixel + 7) / 8;
+
+       divisor = 1024;
+
+       if (!mode->htotal || !mode->vtotal || !mode->clock)
+               return 0;
+
+       active_area = mode->hdisplay * mode->vdisplay;
+       total_area = mode->htotal * mode->vtotal;
+
+       pixels_per_second = active_area * mode->clock * 1000;
+       do_div(pixels_per_second, total_area);
+
+       bandwidth = pixels_per_second * bytes_per_pixel * 100;
+       do_div(bandwidth, divisor);
+
+       return (uint32_t)bandwidth;
+}
+
 static enum drm_mode_status mgag200_mode_config_mode_valid(struct drm_device *dev,
                                                           const struct drm_display_mode *mode)
 {
@@ -1070,6 +1035,33 @@ static enum drm_mode_status mgag200_mode_config_mode_valid(struct drm_device *de
        if (fbpages > max_fbpages)
                return MODE_MEM;
 
+       if (IS_G200_SE(mdev)) {
+               u32 unique_rev_id = mdev->model.g200se.unique_rev_id;
+
+               if (unique_rev_id == 0x01) {
+                       if (mgag200_calculate_mode_bandwidth(mode, max_bpp * 8) > (24400 * 1024))
+                               return MODE_BAD;
+               } else if (unique_rev_id == 0x02) {
+                       if (mgag200_calculate_mode_bandwidth(mode, max_bpp * 8) > (30100 * 1024))
+                               return MODE_BAD;
+               } else {
+                       if (mgag200_calculate_mode_bandwidth(mode, max_bpp * 8) > (55000 * 1024))
+                               return MODE_BAD;
+               }
+       } else if (mdev->type == G200_WB) {
+               if (mgag200_calculate_mode_bandwidth(mode, max_bpp * 8) > (31877 * 1024))
+                       return MODE_BAD;
+       } else if (mdev->type == G200_EV) {
+               if (mgag200_calculate_mode_bandwidth(mode, max_bpp * 8) > (32700 * 1024))
+                       return MODE_BAD;
+       } else if (mdev->type == G200_EH) {
+               if (mgag200_calculate_mode_bandwidth(mode, max_bpp * 8) > (37500 * 1024))
+                       return MODE_BAD;
+       } else if (mdev->type == G200_ER) {
+               if (mgag200_calculate_mode_bandwidth(mode, max_bpp * 8) > (55000 * 1024))
+                       return MODE_BAD;
+       }
+
        return MODE_OK;
 }