[bug report] drm: rcar-du: Add RZ/G2L DSI driver

[Dan Carpenter <error27@gmail.com>]

Hello Biju Das,

The patch 7a043f978ed1: "drm: rcar-du: Add RZ/G2L DSI driver" from
Sep 20, 2022, leads to the following Smatch static checker warning:

	drivers/gpu/drm/rcar-du/rzg2l_mipi_dsi.c:372 rzg2l_mipi_dsi_set_display_timing()
	warn: uninitialized special assign 'vich1ppsetr |= (1 << 15)'

drivers/gpu/drm/rcar-du/rzg2l_mipi_dsi.c
    347 static void rzg2l_mipi_dsi_set_display_timing(struct rzg2l_mipi_dsi *dsi,
    348                                               const struct drm_display_mode *mode)
    349 {
    350         u32 vich1ppsetr;
    351         u32 vich1vssetr;
    352         u32 vich1vpsetr;
    353         u32 vich1hssetr;
    354         u32 vich1hpsetr;
    355         int dsi_format;
    356         u32 delay[2];
    357         u8 index;
    358 
    359         /* Configuration for Pixel Packet */
    360         dsi_format = mipi_dsi_pixel_format_to_bpp(dsi->format);
    361         switch (dsi_format) {
    362         case 24:
    363                 vich1ppsetr = VICH1PPSETR_DT_RGB24;
    364                 break;
    365         case 18:
    366                 vich1ppsetr = VICH1PPSETR_DT_RGB18;
    367                 break;

What if mipi_dsi_pixel_format_to_bpp() returns 16?

    368         }
    369 
    370         if ((dsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) &&
    371             !(dsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST))
--> 372                 vich1ppsetr |= VICH1PPSETR_TXESYNC_PULSE;
                        ^^^^^^^^^^^
Uninitialized.

    373 
    374         rzg2l_mipi_dsi_link_write(dsi, VICH1PPSETR, vich1ppsetr);

regards,
dan carpenter