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authorSimon Glass2020-07-02 21:12:33 -0600
committerBin Meng2020-07-09 12:33:24 +0800
commit551ca0e64744324b0f337bfa4a743db24a2800ca (patch)
tree9017b10d8f4500786304cc036643887b1dd78ae7 /drivers/video
parent7812bbdc373236516b6efa13d879d35d43ca7d01 (diff)
x86: video: Support copy framebuffer with probed devices
For PCI video devices that are not mentioned in the devicetree, U-Boot does not bind a driver before relocation, since PCI is not fully probed at that point. Furthermore it is possible for the video device to be on a secondary bus which is not even scanned. This is fine if the framebuffer is allocated in fixed memory, as it normally is on x86. But when using this as a copy framebuffer, we also need U-Boot to allocate its own cached framebuffer for working in. Since the video driver is never bound before relocation, the framebuffer size is never set and U-Boot does no allocation. Add a new CONFIG option to reserve 16MB of memory for this eventuality. This allows vesa devices to use the copy framebuffer. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Anatolij Gustschin <agust@denx.de> Tested-by: Bin Meng <bmeng.cn@gmail.com>
Diffstat (limited to 'drivers/video')
-rw-r--r--drivers/video/Kconfig19
-rw-r--r--drivers/video/video-uclass.c5
2 files changed, 24 insertions, 0 deletions
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 366e9ab4659..89ad603d886 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -22,6 +22,25 @@ config BACKLIGHT
This provides backlight uclass driver that enables basic panel
backlight support.
+config VIDEO_PCI_DEFAULT_FB_SIZE
+ hex "Default framebuffer size to use if no drivers request it"
+ depends on DM_VIDEO
+ default 0x1000000 if X86 && PCI
+ default 0 if !(X86 && PCI)
+ help
+ Generally, video drivers request the amount of memory they need for
+ the frame buffer when they are bound, by setting the size field in
+ struct video_uc_platdata. That memory is then reserved for use after
+ relocation. But PCI drivers cannot be bound before relocation unless
+ they are mentioned in the devicetree.
+
+ With this value set appropriately, it is possible for PCI video
+ devices to have a framebuffer allocated by U-Boot.
+
+ Note: the framebuffer needs to be large enough to store all pixels at
+ maximum resolution. For example, at 1920 x 1200 with 32 bits per
+ pixel, 2560 * 1600 * 32 / 8 = 0xfa0000 bytes are needed.
+
config VIDEO_COPY
bool "Enable copying the frame buffer to a hardware copy"
depends on DM_VIDEO
diff --git a/drivers/video/video-uclass.c b/drivers/video/video-uclass.c
index 4735a22dc11..650891e49dd 100644
--- a/drivers/video/video-uclass.c
+++ b/drivers/video/video-uclass.c
@@ -97,6 +97,11 @@ int video_reserve(ulong *addrp)
debug("%s: Reserving %lx bytes at %lx for video device '%s'\n",
__func__, size, *addrp, dev->name);
}
+
+ /* Allocate space for PCI video devices in case there were not bound */
+ if (*addrp == gd->video_top)
+ *addrp -= CONFIG_VIDEO_PCI_DEFAULT_FB_SIZE;
+
gd->video_bottom = *addrp;
gd->fb_base = *addrp;
debug("Video frame buffers from %lx to %lx\n", gd->video_bottom,