Merge tag 'drm-misc-next-fixes-2018-10-03' of... (29b90203) · Commits · 戴 / test

drivers/gpu/drm/Kconfig

+20 −0

Original line number	Diff line number	Diff line
		@@ -110,6 +110,26 @@ config DRM_FBDEV_OVERALLOC
		is 100. Typical values for double buffering will be 200,
		triple buffering 300.

		config DRM_FBDEV_LEAK_PHYS_SMEM
		bool "Shamelessly allow leaking of fbdev physical address (DANGEROUS)"
		depends on DRM_FBDEV_EMULATION && EXPERT
		default n
		help
		In order to keep user-space compatibility, we want in certain
		use-cases to keep leaking the fbdev physical address to the
		user-space program handling the fbdev buffer.
		This affects, not only, Amlogic, Allwinner or Rockchip devices
		with ARM Mali GPUs using an userspace Blob.
		This option is not supported by upstream developers and should be
		removed as soon as possible and be considered as a broken and
		legacy behaviour from a modern fbdev device driver.

		Please send any bug reports when using this to your proprietary
		software vendor that requires this.

		If in doubt, say "N" or spread the word to your closed source
		library vendor.

		config DRM_LOAD_EDID_FIRMWARE
		bool "Allow to specify an EDID data set instead of probing for it"
		depends on DRM

drivers/gpu/drm/drm_fb_helper.c

+31 −2

Original line number	Diff line number	Diff line
		@@ -56,6 +56,25 @@ MODULE_PARM_DESC(drm_fbdev_overalloc,
		"Overallocation of the fbdev buffer (%) [default="
		__MODULE_STRING(CONFIG_DRM_FBDEV_OVERALLOC) "]");

		/*
		* In order to keep user-space compatibility, we want in certain use-cases
		* to keep leaking the fbdev physical address to the user-space program
		* handling the fbdev buffer.
		* This is a bad habit essentially kept into closed source opengl driver
		* that should really be moved into open-source upstream projects instead
		* of using legacy physical addresses in user space to communicate with
		* other out-of-tree kernel modules.
		*
		* This module_param should be removed as soon as possible and be
		* considered as a broken and legacy behaviour from a modern fbdev device.
		*/
		#if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
		static bool drm_leak_fbdev_smem = false;
		module_param_unsafe(drm_leak_fbdev_smem, bool, 0600);
		MODULE_PARM_DESC(fbdev_emulation,
		"Allow unsafe leaking fbdev physical smem address [default=false]");
		#endif

		static LIST_HEAD(kernel_fb_helper_list);
		static DEFINE_MUTEX(kernel_fb_helper_lock);

		@@ -2670,6 +2689,10 @@ __drm_fb_helper_initial_config_and_unlock(struct drm_fb_helper *fb_helper,

		info = fb_helper->fbdev;
		info->var.pixclock = 0;
		/* Shamelessly allow physical address leaking to userspace */
		#if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
		if (!drm_leak_fbdev_smem)
		#endif
		/* don't leak any physical addresses to userspace */
		info->flags \|= FBINFO_HIDE_SMEM_START;

		@@ -3081,6 +3104,12 @@ int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
		fbi->screen_size = fb->height * fb->pitches[0];
		fbi->fix.smem_len = fbi->screen_size;
		fbi->screen_buffer = buffer->vaddr;
		/* Shamelessly leak the physical address to user-space */
		#if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
		if (drm_leak_fbdev_smem && fbi->fix.smem_start == 0)
		fbi->fix.smem_start =
		page_to_phys(virt_to_page(fbi->screen_buffer));
		#endif
		strcpy(fbi->fix.id, "DRM emulated");

		drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->format->depth);

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