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Commit c219c2cd authored by Eugeniy Paltsev's avatar Eugeniy Paltsev Committed by Greg Kroah-Hartman
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drm: fb-helper: Reject all pixel format changing requests 



commit db05c481 upstream.

drm fbdev emulation doesn't support changing the pixel format at all,
so reject all pixel format changing requests.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarEugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Reviewed-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20181003164538.5534-1-Eugeniy.Paltsev@synopsys.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 20ff1855

drivers/gpu/drm/drm_fb_helper.c

+26 −65
Original line number Diff line number Diff line
@@ -1490,6 +1490,25 @@ int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd, 
}

EXPORT_SYMBOL(drm_fb_helper_ioctl);



static bool drm_fb_pixel_format_equal(const struct fb_var_screeninfo *var_1,

				      const struct fb_var_screeninfo *var_2)

{

	return var_1->bits_per_pixel == var_2->bits_per_pixel &&

	       var_1->grayscale == var_2->grayscale &&

	       var_1->red.offset == var_2->red.offset &&

	       var_1->red.length == var_2->red.length &&

	       var_1->red.msb_right == var_2->red.msb_right &&

	       var_1->green.offset == var_2->green.offset &&

	       var_1->green.length == var_2->green.length &&

	       var_1->green.msb_right == var_2->green.msb_right &&

	       var_1->blue.offset == var_2->blue.offset &&

	       var_1->blue.length == var_2->blue.length &&

	       var_1->blue.msb_right == var_2->blue.msb_right &&

	       var_1->transp.offset == var_2->transp.offset &&

	       var_1->transp.length == var_2->transp.length &&

	       var_1->transp.msb_right == var_2->transp.msb_right;

}



/**

 * drm_fb_helper_check_var - implementation for &fb_ops.fb_check_var

 * @var: screeninfo to check
@@ -1500,7 +1519,6 @@ int drm_fb_helper_check_var(struct fb_var_screeninfo *var, 
{

	struct drm_fb_helper *fb_helper = info->par;

	struct drm_framebuffer *fb = fb_helper->fb;

	int depth;



	if (var->pixclock != 0 || in_dbg_master())

		return -EINVAL;
@@ -1520,72 +1538,15 @@ int drm_fb_helper_check_var(struct fb_var_screeninfo *var, 
		return -EINVAL;

	}



	switch (var->bits_per_pixel) {

	case 16:

		depth = (var->green.length == 6) ? 16 : 15;

		break;

	case 32:

		depth = (var->transp.length > 0) ? 32 : 24;

		break;

	default:

		depth = var->bits_per_pixel;

		break;

	}



	switch (depth) {

	case 8:

		var->red.offset = 0;

		var->green.offset = 0;

		var->blue.offset = 0;

		var->red.length = 8;

		var->green.length = 8;

		var->blue.length = 8;

		var->transp.length = 0;

		var->transp.offset = 0;

		break;

	case 15:

		var->red.offset = 10;

		var->green.offset = 5;

		var->blue.offset = 0;

		var->red.length = 5;

		var->green.length = 5;

		var->blue.length = 5;

		var->transp.length = 1;

		var->transp.offset = 15;

		break;

	case 16:

		var->red.offset = 11;

		var->green.offset = 5;

		var->blue.offset = 0;

		var->red.length = 5;

		var->green.length = 6;

		var->blue.length = 5;

		var->transp.length = 0;

		var->transp.offset = 0;

		break;

	case 24:

		var->red.offset = 16;

		var->green.offset = 8;

		var->blue.offset = 0;

		var->red.length = 8;

		var->green.length = 8;

		var->blue.length = 8;

		var->transp.length = 0;

		var->transp.offset = 0;

		break;

	case 32:

		var->red.offset = 16;

		var->green.offset = 8;

		var->blue.offset = 0;

		var->red.length = 8;

		var->green.length = 8;

		var->blue.length = 8;

		var->transp.length = 8;

		var->transp.offset = 24;

		break;

	default:

	/*

	 * drm fbdev emulation doesn't support changing the pixel format at all,

	 * so reject all pixel format changing requests.

	 */

	if (!drm_fb_pixel_format_equal(var, &info->var)) {

		DRM_DEBUG("fbdev emulation doesn't support changing the pixel format\n");

		return -EINVAL;

	}



	return 0;

}

EXPORT_SYMBOL(drm_fb_helper_check_var);