[PATCH 00/12] treewide: Fix GENMASK misuses

[PATCH 00/12] treewide: Fix GENMASK misuses

[Joe Perches]

These GENMASK uses are inverted argument order and the
actual masks produced are incorrect.  Fix them.

Add checkpatch tests to help avoid more misuses too.

Joe Perches (12):
  checkpatch: Add GENMASK tests
  clocksource/drivers/npcm: Fix misuse of GENMASK macro
  drm: aspeed_gfx: Fix misuse of GENMASK macro
  iio: adc: max9611: Fix misuse of GENMASK macro
  irqchip/gic-v3-its: Fix misuse of GENMASK macro
  mmc: meson-mx-sdio: Fix misuse of GENMASK macro
  net: ethernet: mediatek: Fix misuses of GENMASK macro
  net: stmmac: Fix misuses of GENMASK macro
  rtw88: Fix misuse of GENMASK macro
  phy: amlogic: G12A: Fix misuse of GENMASK macro
  staging: media: cedrus: Fix misuse of GENMASK macro
  ASoC: wcd9335: Fix misuse of GENMASK macro

 drivers/clocksource/timer-npcm7xx.c               |  2 +-
 drivers/gpu/drm/aspeed/aspeed_gfx.h               |  2 +-
 drivers/iio/adc/max9611.c                         |  2 +-
 drivers/irqchip/irq-gic-v3-its.c                  |  2 +-
 drivers/mmc/host/meson-mx-sdio.c                  |  2 +-
 drivers/net/ethernet/mediatek/mtk_eth_soc.h       |  2 +-
 drivers/net/ethernet/mediatek/mtk_sgmii.c         |  2 +-
 drivers/net/ethernet/stmicro/stmmac/descs.h       |  2 +-
 drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c |  4 ++--
 drivers/net/wireless/realtek/rtw88/rtw8822b.c     |  2 +-
 drivers/phy/amlogic/phy-meson-g12a-usb2.c         |  2 +-
 drivers/staging/media/sunxi/cedrus/cedrus_regs.h  |  2 +-
 scripts/checkpatch.pl                             | 15 +++++++++++++++
 sound/soc/codecs/wcd-clsh-v2.c                    |  2 +-
 14 files changed, 29 insertions(+), 14 deletions(-)

-- 
2.15.0

[PATCH 03/12] drm: aspeed_gfx: Fix misuse of GENMASK macro

[Joe Perches]

Arguments are supposed to be ordered high then low.

Signed-off-by: Joe Perches <joe@perches.com>
---
 drivers/gpu/drm/aspeed/aspeed_gfx.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx.h b/drivers/gpu/drm/aspeed/aspeed_gfx.h
index a10358bb61ec..095ea03e5833 100644
--- a/drivers/gpu/drm/aspeed/aspeed_gfx.h
+++ b/drivers/gpu/drm/aspeed/aspeed_gfx.h
@@ -74,7 +74,7 @@ int aspeed_gfx_create_output(struct drm_device *drm);
 /* CTRL2 */
 #define CRT_CTRL_DAC_EN			BIT(0)
 #define CRT_CTRL_VBLANK_LINE(x)		(((x) << 20) & CRT_CTRL_VBLANK_LINE_MASK)
-#define CRT_CTRL_VBLANK_LINE_MASK	GENMASK(20, 31)
+#define CRT_CTRL_VBLANK_LINE_MASK	GENMASK(31, 20)
 
 /* CRT_HORIZ0 */
 #define CRT_H_TOTAL(x)			(x)
-- 
2.15.0

[PATCH 00/12] treewide: Fix GENMASK misuses

[Johannes Berg]

On Tue, 2019-07-09 at 22:04 -0700, Joe Perches wrote:
> These GENMASK uses are inverted argument order and the
> actual masks produced are incorrect.  Fix them.
> 
> Add checkpatch tests to help avoid more misuses too.
> 
> Joe Perches (12):
>   checkpatch: Add GENMASK tests

IMHO this doesn't make a lot of sense as a checkpatch test - just throw
in a BUILD_BUG_ON()?

johannes

[PATCH 00/12] treewide: Fix GENMASK misuses

[Russell King - ARM Linux admin]

On Wed, Jul 10, 2019 at 11:17:31AM +0200, Johannes Berg wrote:
> On Tue, 2019-07-09 at 22:04 -0700, Joe Perches wrote:
> > These GENMASK uses are inverted argument order and the
> > actual masks produced are incorrect.  Fix them.
> > 
> > Add checkpatch tests to help avoid more misuses too.
> > 
> > Joe Perches (12):
> >   checkpatch: Add GENMASK tests
> 
> IMHO this doesn't make a lot of sense as a checkpatch test - just throw
> in a BUILD_BUG_ON()?

My personal take on this is that GENMASK() is really not useful, it's
just pure obfuscation and leads to exactly these kinds of mistakes.

Yes, I fully understand the argument that you can just specify the
start and end bits, and it _in theory_ makes the code more readable.

However, the problem is when writing code.  GENMASK(a, b).  Is a the
starting bit or ending bit?  Is b the number of bits?  It's confusing
and causes mistakes resulting in incorrect code.  A BUILD_BUG_ON()
can catch some of the cases, but not all of them.

For example:

	GENMASK(6, 2)

would satisify the requirement that a > b, so a BUILD_BUG_ON() will
not trigger, but was the author meaning 0x3c or 0xc0?

Personally, I've decided I am _not_ going to use GENMASK() in my code
because I struggle to get the macro arguments correct - I'm _much_
happier, and it is way more reliable for me to write the mask in hex
notation.

I think this is where use of a ternary operator would come in use.  The
normal way of writing a number of bits tends to be "a:b", so if GENMASK
took something like GENMASK(6:2), then I'd have less issue with it,
because it's argument is then in a familiar notation.

Yes, I'm sure that someone will point out that the GENMASK arguments
are just in the same order, but that doesn't prevent _me_ frequently
getting it wrong - and that's the point.  The macro seems to me to
cause more problems than it solves.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up
According to speedtest.net: 11.9Mbps down 500kbps up

[PATCH 00/12] treewide: Fix GENMASK misuses

[Joe Perches]

On Wed, 2019-07-10 at 10:43 +0100, Russell King - ARM Linux admin wrote:
> On Wed, Jul 10, 2019 at 11:17:31AM +0200, Johannes Berg wrote:
> > On Tue, 2019-07-09 at 22:04 -0700, Joe Perches wrote:
> > > These GENMASK uses are inverted argument order and the
> > > actual masks produced are incorrect.  Fix them.
> > > 
> > > Add checkpatch tests to help avoid more misuses too.
> > > 
> > > Joe Perches (12):
> > >   checkpatch: Add GENMASK tests
> > 
> > IMHO this doesn't make a lot of sense as a checkpatch test - just throw
> > in a BUILD_BUG_ON()?

I tried that.

It'd can't be done as it's used in declarations
and included in asm files and it uses the UL()
macro.

I also tried just making it do the right thing
whatever the argument order.

Oh well.

> My personal take on this is that GENMASK() is really not useful, it's
> just pure obfuscation and leads to exactly these kinds of mistakes.
> 
> Yes, I fully understand the argument that you can just specify the
> start and end bits, and it _in theory_ makes the code more readable.
> 
> However, the problem is when writing code.  GENMASK(a, b).  Is a the
> starting bit or ending bit?  Is b the number of bits?  It's confusing
> and causes mistakes resulting in incorrect code.  A BUILD_BUG_ON()
> can catch some of the cases, but not all of them.

It's a horrid little macro and I agree with Russell.

I also think if it existed at all it should have been
GENMASK(low, high) not GENMASK(high, low).

I

[PATCH 00/12] treewide: Fix GENMASK misuses

[Joe Perches]

On Wed, 2019-07-10 at 08:45 -0700, Joe Perches wrote:
> On Wed, 2019-07-10 at 10:43 +0100, Russell King - ARM Linux admin wrote:
> > On Wed, Jul 10, 2019 at 11:17:31AM +0200, Johannes Berg wrote:
> > > On Tue, 2019-07-09 at 22:04 -0700, Joe Perches wrote:
> > > > These GENMASK uses are inverted argument order and the
> > > > actual masks produced are incorrect.  Fix them.
> > > > 
> > > > Add checkpatch tests to help avoid more misuses too.
> > > > 
> > > > Joe Perches (12):
> > > >   checkpatch: Add GENMASK tests
> > > 
> > > IMHO this doesn't make a lot of sense as a checkpatch test - just throw
> > > in a BUILD_BUG_ON()?
> 
> I tried that.
> 
> It'd can't be done as it's used in declarations
> and included in asm files and it uses the UL()
> macro.
> 
> I also tried just making it do the right thing
> whatever the argument order.

I forgot.

I also made all those arguments when it was
introduced in 2013.

https://lore.kernel.org/patchwork/patch/414248/

> Oh well.

yeah.

[PATCH 00/12] treewide: Fix GENMASK misuses

[David Miller]

From: Joe Perches <joe@perches.com>
Date: Tue,  9 Jul 2019 22:04:13 -0700

> These GENMASK uses are inverted argument order and the
> actual masks produced are incorrect.  Fix them.
> 
> Add checkpatch tests to help avoid more misuses too.

Patches #7 and #8 applied to 'net', with appropriate Fixes tags
added to #8.

[PATCH 00/12] treewide: Fix GENMASK misuses

[Andrzej Hajda]

Hi Joe,

On 10.07.2019 07:04, Joe Perches wrote:
> These GENMASK uses are inverted argument order and the
> actual masks produced are incorrect.  Fix them.
>
> Add checkpatch tests to help avoid more misuses too.
>
> Joe Perches (12):
>   checkpatch: Add GENMASK tests
>   clocksource/drivers/npcm: Fix misuse of GENMASK macro
>   drm: aspeed_gfx: Fix misuse of GENMASK macro
>   iio: adc: max9611: Fix misuse of GENMASK macro
>   irqchip/gic-v3-its: Fix misuse of GENMASK macro
>   mmc: meson-mx-sdio: Fix misuse of GENMASK macro
>   net: ethernet: mediatek: Fix misuses of GENMASK macro
>   net: stmmac: Fix misuses of GENMASK macro
>   rtw88: Fix misuse of GENMASK macro
>   phy: amlogic: G12A: Fix misuse of GENMASK macro
>   staging: media: cedrus: Fix misuse of GENMASK macro
>   ASoC: wcd9335: Fix misuse of GENMASK macro
>
>  drivers/clocksource/timer-npcm7xx.c               |  2 +-
>  drivers/gpu/drm/aspeed/aspeed_gfx.h               |  2 +-
>  drivers/iio/adc/max9611.c                         |  2 +-
>  drivers/irqchip/irq-gic-v3-its.c                  |  2 +-
>  drivers/mmc/host/meson-mx-sdio.c                  |  2 +-
>  drivers/net/ethernet/mediatek/mtk_eth_soc.h       |  2 +-
>  drivers/net/ethernet/mediatek/mtk_sgmii.c         |  2 +-
>  drivers/net/ethernet/stmicro/stmmac/descs.h       |  2 +-
>  drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c |  4 ++--
>  drivers/net/wireless/realtek/rtw88/rtw8822b.c     |  2 +-
>  drivers/phy/amlogic/phy-meson-g12a-usb2.c         |  2 +-
>  drivers/staging/media/sunxi/cedrus/cedrus_regs.h  |  2 +-
>  scripts/checkpatch.pl                             | 15 +++++++++++++++
>  sound/soc/codecs/wcd-clsh-v2.c                    |  2 +-
>  14 files changed, 29 insertions(+), 14 deletions(-)
>
After adding following compile time check:

------

diff --git a/Makefile b/Makefile
index 5102b2bbd224..ac4ea5f443a9 100644
--- a/Makefile
+++ b/Makefile
@@ -457,7 +457,7 @@ KBUILD_AFLAGS?? := -D__ASSEMBLY__ -fno-PIE
?KBUILD_CFLAGS?? := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
?????????????????? -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
?????????????????? -Werror=implicit-function-declaration
-Werror=implicit-int \
-????????????????? -Wno-format-security \
+????????????????? -Wno-format-security -Werror=div-by-zero \
?????????????????? -std=gnu89
?KBUILD_CPPFLAGS := -D__KERNEL__
?KBUILD_AFLAGS_KERNEL :=
diff --git a/include/linux/bits.h b/include/linux/bits.h
index 669d69441a62..61d74b103055 100644
--- a/include/linux/bits.h
+++ b/include/linux/bits.h
@@ -19,11 +19,11 @@
? * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
? */
?#define GENMASK(h, l) \
-?????? (((~UL(0)) - (UL(1) << (l)) + 1) & \
+?????? (((~UL(0)) - (UL(1) << (l)) + 1 + 0/((h) >= (l))) & \
???????? (~UL(0) >> (BITS_PER_LONG - 1 - (h))))
?
?#define GENMASK_ULL(h, l) \
-?????? (((~ULL(0)) - (ULL(1) << (l)) + 1) & \
+?????? (((~ULL(0)) - (ULL(1) << (l)) + 1 + 0/((h) >= (l))) & \
???????? (~ULL(0) >> (BITS_PER_LONG_LONG - 1 - (h))))
?
?#endif /* __LINUX_BITS_H */

-------

I was able to detect one more GENMASK misue (AARCH64, allyesconfig):

? CC????? drivers/phy/rockchip/phy-rockchip-inno-hdmi.o
In file included from ../include/linux/bitops.h:5:0,
???????????????? from ../include/linux/kernel.h:12,
???????????????? from ../include/linux/clk.h:13,
???????????????? from ../drivers/phy/rockchip/phy-rockchip-inno-hdmi.c:9:
../drivers/phy/rockchip/phy-rockchip-inno-hdmi.c: In function
?inno_hdmi_phy_rk3328_power_on?:
../include/linux/bits.h:22:37: error: division by zero [-Werror=div-by-zero]
? (((~UL(0)) - (UL(1) << (l)) + 1 + 0/((h) >= (l))) & \
???????????????????????????????????? ^
../drivers/phy/rockchip/phy-rockchip-inno-hdmi.c:24:42: note: in
expansion of macro ?GENMASK?
?#define UPDATE(x, h, l)? (((x) << (l)) & GENMASK((h), (l)))
????????????????????????????????????????? ^~~~~~~
../drivers/phy/rockchip/phy-rockchip-inno-hdmi.c:201:50: note: in
expansion of macro ?UPDATE?
?#define RK3328_TERM_RESISTOR_CALIB_SPEED_7_0(x)? UPDATE(x, 7, 9)
????????????????????????????????????????????????? ^~~~~~
../drivers/phy/rockchip/phy-rockchip-inno-hdmi.c:1046:26: note: in
expansion of macro ?RK3328_TERM_RESISTOR_CALIB_SPEED_7_0?
?? inno_write(inno, 0xc6, RK3328_TERM_RESISTOR_CALIB_SPEED_7_0(v));


Of course I do not advise to add the check as is to Kernel - it is
undefined behavior area AFAIK.


Regards

Andrzej

[PATCH 03/12] drm: aspeed_gfx: Fix misuse of GENMASK macro

[Joe Perches]

On Tue, 2019-07-09 at 22:04 -0700, Joe Perches wrote:
> Arguments are supposed to be ordered high then low.
> 
> Signed-off-by: Joe Perches <joe@perches.com>
> ---
>  drivers/gpu/drm/aspeed/aspeed_gfx.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx.h b/drivers/gpu/drm/aspeed/aspeed_gfx.h
> index a10358bb61ec..095ea03e5833 100644
> --- a/drivers/gpu/drm/aspeed/aspeed_gfx.h
> +++ b/drivers/gpu/drm/aspeed/aspeed_gfx.h
> @@ -74,7 +74,7 @@ int aspeed_gfx_create_output(struct drm_device *drm);
>  /* CTRL2 */
>  #define CRT_CTRL_DAC_EN			BIT(0)
>  #define CRT_CTRL_VBLANK_LINE(x)		(((x) << 20) & CRT_CTRL_VBLANK_LINE_MASK)
> -#define CRT_CTRL_VBLANK_LINE_MASK	GENMASK(20, 31)
> +#define CRT_CTRL_VBLANK_LINE_MASK	GENMASK(31, 20)

ping?

[PATCH 03/12] drm: aspeed_gfx: Fix misuse of GENMASK macro

[Andrew Jeffery]

On Thu, 25 Jul 2019, at 02:46, Joe Perches wrote:
> On Tue, 2019-07-09 at 22:04 -0700, Joe Perches wrote:
> > Arguments are supposed to be ordered high then low.
> > 
> > Signed-off-by: Joe Perches <joe@perches.com>
> > ---
> >  drivers/gpu/drm/aspeed/aspeed_gfx.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx.h b/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > index a10358bb61ec..095ea03e5833 100644
> > --- a/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > +++ b/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > @@ -74,7 +74,7 @@ int aspeed_gfx_create_output(struct drm_device *drm);
> >  /* CTRL2 */
> >  #define CRT_CTRL_DAC_EN			BIT(0)
> >  #define CRT_CTRL_VBLANK_LINE(x)		(((x) << 20) & CRT_CTRL_VBLANK_LINE_MASK)
> > -#define CRT_CTRL_VBLANK_LINE_MASK	GENMASK(20, 31)
> > +#define CRT_CTRL_VBLANK_LINE_MASK	GENMASK(31, 20)

Reviewed-by: Andrew Jeffery <andrew@aj.id.au>

> 
> ping?
> 
> 
>

[PATCH 03/12] drm: aspeed_gfx: Fix misuse of GENMASK macro

[Joe Perches]

On Thu, 2019-07-25 at 10:40 +0930, Andrew Jeffery wrote:
> 
> On Thu, 25 Jul 2019, at 02:46, Joe Perches wrote:
> > On Tue, 2019-07-09 at 22:04 -0700, Joe Perches wrote:
> > > Arguments are supposed to be ordered high then low.
> > > 
> > > Signed-off-by: Joe Perches <joe@perches.com>
> > > ---
> > >  drivers/gpu/drm/aspeed/aspeed_gfx.h | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx.h b/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > > index a10358bb61ec..095ea03e5833 100644
> > > --- a/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > > +++ b/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > > @@ -74,7 +74,7 @@ int aspeed_gfx_create_output(struct drm_device *drm);
> > >  /* CTRL2 */
> > >  #define CRT_CTRL_DAC_EN			BIT(0)
> > >  #define CRT_CTRL_VBLANK_LINE(x)		(((x) << 20) & CRT_CTRL_VBLANK_LINE_MASK)
> > > -#define CRT_CTRL_VBLANK_LINE_MASK	GENMASK(20, 31)
> > > +#define CRT_CTRL_VBLANK_LINE_MASK	GENMASK(31, 20)
> 
> Reviewed-by: Andrew Jeffery <andrew@aj.id.au>

This hardly needs a review, it needs to be applied.
There's a nominal git tree for aspeed here:

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/joel/aspeed.git

But who's going to do apply this?

[PATCH 03/12] drm: aspeed_gfx: Fix misuse of GENMASK macro

[Joel Stanley]

On Thu, 25 Jul 2019 at 01:18, Joe Perches <joe@perches.com> wrote:
>
> On Thu, 2019-07-25 at 10:40 +0930, Andrew Jeffery wrote:
> >
> > On Thu, 25 Jul 2019, at 02:46, Joe Perches wrote:
> > > On Tue, 2019-07-09 at 22:04 -0700, Joe Perches wrote:
> > > > Arguments are supposed to be ordered high then low.
> > > >
> > > > Signed-off-by: Joe Perches <joe@perches.com>
> > > > ---
> > > >  drivers/gpu/drm/aspeed/aspeed_gfx.h | 2 +-
> > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx.h b/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > > > index a10358bb61ec..095ea03e5833 100644
> > > > --- a/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > > > +++ b/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > > > @@ -74,7 +74,7 @@ int aspeed_gfx_create_output(struct drm_device *drm);
> > > >  /* CTRL2 */
> > > >  #define CRT_CTRL_DAC_EN                  BIT(0)
> > > >  #define CRT_CTRL_VBLANK_LINE(x)          (((x) << 20) & CRT_CTRL_VBLANK_LINE_MASK)
> > > > -#define CRT_CTRL_VBLANK_LINE_MASK        GENMASK(20, 31)
> > > > +#define CRT_CTRL_VBLANK_LINE_MASK        GENMASK(31, 20)
> >
> > Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
>
> This hardly needs a review, it needs to be applied.
> There's a nominal git tree for aspeed here:
>
> T:      git git://git.kernel.org/pub/scm/linux/kernel/git/joel/aspeed.git
>
> But who's going to do apply this?

This is a DRM patch, so it goes through the DRM tree. I am a
co-maintainer there and can apply it once I remember how to drive the
tools.

(FYI, this macro is not used by the current driver).

Cheers,

Joel

[PATCH 03/12] drm: aspeed_gfx: Fix misuse of GENMASK macro

[Joe Perches]

On Thu, 2019-07-25 at 02:52 +0000, Joel Stanley wrote:
> On Thu, 25 Jul 2019 at 01:18, Joe Perches <joe@perches.com> wrote:
> > On Thu, 2019-07-25 at 10:40 +0930, Andrew Jeffery wrote:
> > > On Thu, 25 Jul 2019, at 02:46, Joe Perches wrote:
> > > > On Tue, 2019-07-09 at 22:04 -0700, Joe Perches wrote:
> > > > > Arguments are supposed to be ordered high then low.
> > > > > 
> > > > > Signed-off-by: Joe Perches <joe@perches.com>
> > > > > ---
> > > > >  drivers/gpu/drm/aspeed/aspeed_gfx.h | 2 +-
> > > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > > > 
> > > > > diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx.h b/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > > > > index a10358bb61ec..095ea03e5833 100644
> > > > > --- a/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > > > > +++ b/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > > > > @@ -74,7 +74,7 @@ int aspeed_gfx_create_output(struct drm_device *drm);
> > > > >  /* CTRL2 */
> > > > >  #define CRT_CTRL_DAC_EN                  BIT(0)
> > > > >  #define CRT_CTRL_VBLANK_LINE(x)          (((x) << 20) & CRT_CTRL_VBLANK_LINE_MASK)
> > > > > -#define CRT_CTRL_VBLANK_LINE_MASK        GENMASK(20, 31)
> > > > > +#define CRT_CTRL_VBLANK_LINE_MASK        GENMASK(31, 20)
> > > 
> > > Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
> > 
> > This hardly needs a review, it needs to be applied.
> > There's a nominal git tree for aspeed here:
> > 
> > T:      git git://git.kernel.org/pub/scm/linux/kernel/git/joel/aspeed.git
> > 
> > But who's going to do apply this?
> 
> This is a DRM patch, so it goes through the DRM tree. I am a
> co-maintainer there and can apply it once I remember how to drive the
> tools.
> 
> (FYI, this macro is not used by the current driver).

Then perhaps CRT_CTRL_VBLANK and _MASK defines
should be removed instead.

cheers, Joe