Koen Kooi had written, on 05/14/2010 06:18 AM, the following:
Op 14 mei 2010, om 12:58 heeft Nishanth Menon het volgende geschreven:
Koen Kooi had written, on 05/14/2010 05:39 AM, the following:
Op 14 mei 2010, om 12:03 heeft Guruswamy, Senthilvadivu het volgende geschreven:
-----Original Message-----
From: Tomi Valkeinen [mailto:tomi.valkeinen@xxxxxxxxx] Sent: Friday, May 14, 2010 12:54 PM
To: Guruswamy, Senthilvadivu
Cc: linux-omap@xxxxxxxxxxxxxxx; linux-fbdev@xxxxxxxxxxxxxxx; tony@xxxxxxxxxxx; Hiremath, Vaibhav
Subject: Re: [PATCH v2 0/2] DSS2:Allow FB to build without VRFB
Hi,
On Thu, 2010-05-13 at 17:20 +0200, ext Senthilvadivu Guruswamy wrote:
From: Senthilvadivu Guruswamy <svadivu@xxxxxx>
Hi all,
This patch series replaces the patch "DSS2 Include VRFB into omap2-3build only"
Thanks for the review comments.
The intent of this series is to split the patch into 2 logical
patches and also to incorporate the comments on multi-omap build.
In this series, Kconfig is changed to have OMAP2_VRFB depend on ARCH_OMAP2 and ARCH_OMAP3.
This change takes care of the multi-omap builds.
This patch would allow successful build of omap_4430sdp_defconfig when OMAP2_DSS and FB_OMAP2 is enabled from menuconfig.
For verification: Generated the .config on omap3_defconfig with DSS
and FB enabled. Generated .config is same with and without
the patch.
List of Changed Files:
arch/arm/plat-omap/include/plat/vrfb.h
drivers/video/omap2/Kconfig
drivers/video/omap2/omapfb/Kconfig
The patch set makes VRFB optional. What happens if VRFB is turned off,
and the user uses VRFB for a framebuffer?
[Senthil] This patch keeps VRFB=y for ARCH_OMAP2 and ARCH_OMAP3.
User would have got an option to turn it OFF if it had appeared in the menuconfig selections. I did not give that option in menuconfig explicitly. ie config OMAP2_VRFB
bool <No name given here>
Suppose on a build the user deliberately gives "CONFIG_OMAP2_VRFB not set",
then VRFB functions are made as empty functions by the compiler.
This is fine as long as the user does not say omapfb.vrfb=1.
But if the user sets omapfb.vrfb=1, then it is a wrong usage of the bootargs
as he has already deliberately changed the defconfig to say "VRFB not set".
The result of his experiment: No bootup on the board as the vaddr of VRFB is populated nor of the normal RAM buffer.
And that is unacceptable when working with customers (or users in the open
source world). Instead of the kernel hacker spending an hour or 2 on a proper
solution we now need to waste a whole lot more time supporting customers who
pass vrfb in bootargs without knowing that it's turned off in the kernel.
But why use bootargs?
Because (for some unknown reason) you can't toggle vrfb at runtime. If you realize
> you need rotation you need to reboot. I guess it's because the memory
layout for
>vrfb is completely different, but again, I'm not a kernel hacker :)
Sorry, I am no DSS hacker myself, but looking at mainline 2.6.34-rc6
kernel drivers/video/omap2/omapfb/omapfb-main.c, as part of late_init,
omapfb_init gets called -> which causes probe to be called if there is a
display around, which calls create_framebuffers and based on the
rotation flag DMA or VRFB bootargs call to allocate goes to
drivers/video/omap2/vrfb.c, i see request_mem_region and
release_mem_region from a physical address mapped - so ok.. we loose
some of our memory map..
Since this entire fuss is about being able to select the type of
rotation... how about changing vrfb to rotation_type which defaults to
best possible for the silicon as indicated by FEATURES as I have been
mentioning so far..
just an idea about what I am talking about, here is an illustration patch:
diff --git a/Documentation/arm/OMAP/DSS b/Documentation/arm/OMAP/DSS
index 0af0e9e..b3df400 100644
--- a/Documentation/arm/OMAP/DSS
+++ b/Documentation/arm/OMAP/DSS
@@ -279,8 +279,11 @@ omapfb.test=<y|n>
- Draw test pattern to framebuffer whenever framebuffer settings change.
You need to have OMAPFB debug support enabled in kernel config.
-omapfb.vrfb=<y|n>
- - Use VRFB rotation for all framebuffers.
+omapfb.rotation_type= 0|1|2
+ - Select rotation type on hardware
+ 0 - Default: Use Optimal rotation style for the silicon
+ 1 - Force use VRFB rotation for all framebuffers if available
+ 2 - Use DSS to rotate all framebuffers
omapfb.rotate=<angle>
- Default rotation applied to all framebuffers.
diff --git a/arch/arm/plat-omap/include/plat/cpu.h
b/arch/arm/plat-omap/include/plat/cpu.h
index 7514174..52aebae 100644
--- a/arch/arm/plat-omap/include/plat/cpu.h
+++ b/arch/arm/plat-omap/include/plat/cpu.h
@@ -444,6 +444,7 @@ extern u32 omap3_features;
#define OMAP3_HAS_NEON BIT(3)
#define OMAP3_HAS_ISP BIT(4)
#define OMAP3_HAS_192MHZ_CLK BIT(5)
+#define OMAP3_HAS_VRFB BIT(6)
#define OMAP3_HAS_FEATURE(feat,flag) \
static inline unsigned int omap3_has_ ##feat(void) \
@@ -457,5 +458,6 @@ OMAP3_HAS_FEATURE(iva, IVA)
OMAP3_HAS_FEATURE(neon, NEON)
OMAP3_HAS_FEATURE(isp, ISP)
OMAP3_HAS_FEATURE(192mhz_clk, 192MHZ_CLK)
+OMAP3_HAS_FEATURE(vrfb, VRFB)
#endif
diff --git a/drivers/video/omap2/omapfb/omapfb-main.c
b/drivers/video/omap2/omapfb/omapfb-main.c
index 4b4506d..b0cc251 100644
--- a/drivers/video/omap2/omapfb/omapfb-main.c
+++ b/drivers/video/omap2/omapfb/omapfb-main.c
@@ -33,6 +33,7 @@
#include <plat/display.h>
#include <plat/vram.h>
#include <plat/vrfb.h>
+#include <plat/cpu.h>
#include "omapfb.h"
@@ -43,7 +44,7 @@
static char *def_mode;
static char *def_vram;
-static int def_vrfb;
+static int def_rotate_type;
static int def_rotate;
static int def_mirror;
@@ -1872,8 +1873,14 @@ static int omapfb_create_framebuffers(struct
omapfb2_device *fbdev)
ofbi->id = i;
/* assign these early, so that fb alloc can use them */
- ofbi->rotation_type = def_vrfb ? OMAP_DSS_ROT_VRFB :
- OMAP_DSS_ROT_DMA;
+
+ /* Unless forced to use otherwise, use vrfb */
+ if (omap3_has_vrfb())
+ ofbi->rotation_type = (def_rot_style == 2) ?
+ OMAP_DSS_ROT_DMA : OMAP_DSS_ROT_VRFB;
+ else
+ ofbi->rotation_type = OMAP_DSS_ROT_DMA;
+
ofbi->mirror = def_mirror;
fbdev->num_fbs++;
@@ -2272,7 +2279,7 @@ static void __exit omapfb_exit(void)
module_param_named(mode, def_mode, charp, 0);
module_param_named(vram, def_vram, charp, 0);
module_param_named(rotate, def_rotate, int, 0);
-module_param_named(vrfb, def_vrfb, bool, 0);
+module_param_named(rotation_type, def_rot_style, int, 0);
module_param_named(mirror, def_mirror, bool, 0);
/* late_initcall to let panel/ctrl drivers loaded first.
--
Regards,
Nishanth Menon
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