Re: [PATCH v2 02/12] drm/armada: Use regular fbdev I/O helpers
Hi
Am 15.05.23 um 20:04 schrieb Russell King (Oracle):
On Mon, May 15, 2023 at 07:55:44PM +0200, Sam Ravnborg wrote:
Hi Thomas,
On Mon, May 15, 2023 at 11:40:23AM +0200, Thomas Zimmermann wrote:
Use the regular fbdev helpers for framebuffer I/O instead of DRM's
helpers. Armada does not use damage handling, so DRM's fbdev helpers
are mere wrappers around the fbdev code.
By using fbdev helpers directly within each DRM fbdev emulation,
we can eventually remove DRM's wrapper functions entirely.
v2:
* use FB_IO_HELPERS option
Signed-off-by: Thomas Zimmermann
Cc: Russell King
---
drivers/gpu/drm/armada/Kconfig| 1 +
drivers/gpu/drm/armada/armada_fbdev.c | 9 -
2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/armada/Kconfig b/drivers/gpu/drm/armada/Kconfig
index f5c66d89ba99..5afade25e217 100644
--- a/drivers/gpu/drm/armada/Kconfig
+++ b/drivers/gpu/drm/armada/Kconfig
@@ -3,6 +3,7 @@ config DRM_ARMADA
tristate "DRM support for Marvell Armada SoCs"
depends on DRM && HAVE_CLK && ARM && MMU
select DRM_KMS_HELPER
+ select FB_IO_HELPERS if DRM_FBDEV_EMULATION
help
Support the "LCD" controllers found on the Marvell Armada 510
devices. There are two controllers on the device, each controller
diff --git a/drivers/gpu/drm/armada/armada_fbdev.c
b/drivers/gpu/drm/armada/armada_fbdev.c
index 0a5fd1aa86eb..6c3bbaf53569 100644
--- a/drivers/gpu/drm/armada/armada_fbdev.c
+++ b/drivers/gpu/drm/armada/armada_fbdev.c
@@ -5,6 +5,7 @@
*/
#include
+#include
#include
#include
@@ -34,11 +35,9 @@ static void armada_fbdev_fb_destroy(struct fb_info *info)
static const struct fb_ops armada_fb_ops = {
.owner = THIS_MODULE,
DRM_FB_HELPER_DEFAULT_OPS,
- .fb_read= drm_fb_helper_cfb_read,
- .fb_write = drm_fb_helper_cfb_write,
I had expected to see
.fb_read = fb_io_read,
But maybe this only used when using damage handling?
Likewise for drm_fb_helper_cfb_write.
??
- .fb_fillrect= drm_fb_helper_cfb_fillrect,
- .fb_copyarea= drm_fb_helper_cfb_copyarea,
- .fb_imageblit = drm_fb_helper_cfb_imageblit,
+ .fb_fillrect= cfb_fillrect,
+ .fb_copyarea= cfb_copyarea,
+ .fb_imageblit = cfb_imageblit,
This part is as expected.
Well, to me it looks like this has gone through an entire circular set
of revisions:
commit e8b70e4dd7b5dad7c2379de6e0851587bf86bfd6
Author: Archit Taneja
Date: Wed Jul 22 14:58:04 2015 +0530
drm/armada: Use new drm_fb_helper functions
- .fb_fillrect= cfb_fillrect,
- .fb_copyarea= cfb_copyarea,
- .fb_imageblit = cfb_imageblit,
+ .fb_fillrect= drm_fb_helper_cfb_fillrect,
+ .fb_copyarea= drm_fb_helper_cfb_copyarea,
+ .fb_imageblit = drm_fb_helper_cfb_imageblit,
commit 983780918c759fdbbf0bf033e701bbff75d2af23
Author: Thomas Zimmermann
Date: Thu Nov 3 16:14:40 2022 +0100
drm/fb-helper: Perform all fbdev I/O with the same implementation
+ .fb_read= drm_fb_helper_cfb_read,
+ .fb_write = drm_fb_helper_cfb_write,
and now effectively those two changes are being reverted, so we'd
now be back to the pre-July 2015 state of affairs. As I believe
the fbdev layer has been stable, this change merely reverts the
driver back to what it once was.
Not quite. One long-standing problem has been that fbdev does not
protect its public interfaces with CONFIG_FB. If fbdev had been
disabled, DRM drivers could no longer be linked/loaded. DRM wrappers
solved this. The issue has recently been fixed for all of DRM. DRM does
not build it's fbdev emulation if CONFIG_FB has been disabled.
Another thing was that the original DRM wrappers might have been
different from fbdev's I/O helpers in subtle ways. But now they are
simple wrappers around their fbdev counterparts; plus the option of
additional damage handling. But such damage handling is better
implemented by the driver itself. The two cases that require it, i915
and fbdev-generic, are different enough that each should probably have
it's own code.
Best regards
Thomas
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
OpenPGP_signature
Description: OpenPGP digital signature
Re: [PATCH v2 02/12] drm/armada: Use regular fbdev I/O helpers
Hi
Am 15.05.23 um 19:55 schrieb Sam Ravnborg:
Hi Thomas,
On Mon, May 15, 2023 at 11:40:23AM +0200, Thomas Zimmermann wrote:
Use the regular fbdev helpers for framebuffer I/O instead of DRM's
helpers. Armada does not use damage handling, so DRM's fbdev helpers
are mere wrappers around the fbdev code.
By using fbdev helpers directly within each DRM fbdev emulation,
we can eventually remove DRM's wrapper functions entirely.
v2:
* use FB_IO_HELPERS option
Signed-off-by: Thomas Zimmermann
Cc: Russell King
---
drivers/gpu/drm/armada/Kconfig| 1 +
drivers/gpu/drm/armada/armada_fbdev.c | 9 -
2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/armada/Kconfig b/drivers/gpu/drm/armada/Kconfig
index f5c66d89ba99..5afade25e217 100644
--- a/drivers/gpu/drm/armada/Kconfig
+++ b/drivers/gpu/drm/armada/Kconfig
@@ -3,6 +3,7 @@ config DRM_ARMADA
tristate "DRM support for Marvell Armada SoCs"
depends on DRM && HAVE_CLK && ARM && MMU
select DRM_KMS_HELPER
+ select FB_IO_HELPERS if DRM_FBDEV_EMULATION
help
Support the "LCD" controllers found on the Marvell Armada 510
devices. There are two controllers on the device, each controller
diff --git a/drivers/gpu/drm/armada/armada_fbdev.c
b/drivers/gpu/drm/armada/armada_fbdev.c
index 0a5fd1aa86eb..6c3bbaf53569 100644
--- a/drivers/gpu/drm/armada/armada_fbdev.c
+++ b/drivers/gpu/drm/armada/armada_fbdev.c
@@ -5,6 +5,7 @@
*/
#include
+#include
#include
#include
@@ -34,11 +35,9 @@ static void armada_fbdev_fb_destroy(struct fb_info *info)
static const struct fb_ops armada_fb_ops = {
.owner = THIS_MODULE,
DRM_FB_HELPER_DEFAULT_OPS,
- .fb_read= drm_fb_helper_cfb_read,
- .fb_write = drm_fb_helper_cfb_write,
I had expected to see
.fb_read = fb_io_read,
But maybe this only used when using damage handling?
fb_io_read() and fb_io_write() are the default implementations. They are
called when no callback has been set. All the other fbdev drivers leave
them out, so I kept this pattern for the DRM side as well.
Best regards
Thomas
Likewise for drm_fb_helper_cfb_write.
??
- .fb_fillrect= drm_fb_helper_cfb_fillrect,
- .fb_copyarea= drm_fb_helper_cfb_copyarea,
- .fb_imageblit = drm_fb_helper_cfb_imageblit,
+ .fb_fillrect= cfb_fillrect,
+ .fb_copyarea= cfb_copyarea,
+ .fb_imageblit = cfb_imageblit,
This part is as expected.
Sam
.fb_destroy = armada_fbdev_fb_destroy,
};
--
2.40.1
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
OpenPGP_signature
Description: OpenPGP digital signature
Re: [PATCH v2 02/12] drm/armada: Use regular fbdev I/O helpers
On Mon, May 15, 2023 at 07:55:44PM +0200, Sam Ravnborg wrote:
> Hi Thomas,
>
> On Mon, May 15, 2023 at 11:40:23AM +0200, Thomas Zimmermann wrote:
> > Use the regular fbdev helpers for framebuffer I/O instead of DRM's
> > helpers. Armada does not use damage handling, so DRM's fbdev helpers
> > are mere wrappers around the fbdev code.
> >
> > By using fbdev helpers directly within each DRM fbdev emulation,
> > we can eventually remove DRM's wrapper functions entirely.
> >
> > v2:
> > * use FB_IO_HELPERS option
> >
> > Signed-off-by: Thomas Zimmermann
> > Cc: Russell King
> > ---
> > drivers/gpu/drm/armada/Kconfig| 1 +
> > drivers/gpu/drm/armada/armada_fbdev.c | 9 -
> > 2 files changed, 5 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/armada/Kconfig b/drivers/gpu/drm/armada/Kconfig
> > index f5c66d89ba99..5afade25e217 100644
> > --- a/drivers/gpu/drm/armada/Kconfig
> > +++ b/drivers/gpu/drm/armada/Kconfig
> > @@ -3,6 +3,7 @@ config DRM_ARMADA
> > tristate "DRM support for Marvell Armada SoCs"
> > depends on DRM && HAVE_CLK && ARM && MMU
> > select DRM_KMS_HELPER
> > + select FB_IO_HELPERS if DRM_FBDEV_EMULATION
> > help
> > Support the "LCD" controllers found on the Marvell Armada 510
> > devices. There are two controllers on the device, each controller
> > diff --git a/drivers/gpu/drm/armada/armada_fbdev.c
> > b/drivers/gpu/drm/armada/armada_fbdev.c
> > index 0a5fd1aa86eb..6c3bbaf53569 100644
> > --- a/drivers/gpu/drm/armada/armada_fbdev.c
> > +++ b/drivers/gpu/drm/armada/armada_fbdev.c
> > @@ -5,6 +5,7 @@
> > */
> >
> > #include
> > +#include
> > #include
> > #include
> >
> > @@ -34,11 +35,9 @@ static void armada_fbdev_fb_destroy(struct fb_info *info)
> > static const struct fb_ops armada_fb_ops = {
> > .owner = THIS_MODULE,
> > DRM_FB_HELPER_DEFAULT_OPS,
> > - .fb_read= drm_fb_helper_cfb_read,
> > - .fb_write = drm_fb_helper_cfb_write,
> I had expected to see
> .fb_read = fb_io_read,
>
> But maybe this only used when using damage handling?
>
> Likewise for drm_fb_helper_cfb_write.
>
> ??
>
> > - .fb_fillrect= drm_fb_helper_cfb_fillrect,
> > - .fb_copyarea= drm_fb_helper_cfb_copyarea,
> > - .fb_imageblit = drm_fb_helper_cfb_imageblit,
> > + .fb_fillrect= cfb_fillrect,
> > + .fb_copyarea= cfb_copyarea,
> > + .fb_imageblit = cfb_imageblit,
>
> This part is as expected.
Well, to me it looks like this has gone through an entire circular set
of revisions:
commit e8b70e4dd7b5dad7c2379de6e0851587bf86bfd6
Author: Archit Taneja
Date: Wed Jul 22 14:58:04 2015 +0530
drm/armada: Use new drm_fb_helper functions
- .fb_fillrect= cfb_fillrect,
- .fb_copyarea= cfb_copyarea,
- .fb_imageblit = cfb_imageblit,
+ .fb_fillrect= drm_fb_helper_cfb_fillrect,
+ .fb_copyarea= drm_fb_helper_cfb_copyarea,
+ .fb_imageblit = drm_fb_helper_cfb_imageblit,
commit 983780918c759fdbbf0bf033e701bbff75d2af23
Author: Thomas Zimmermann
Date: Thu Nov 3 16:14:40 2022 +0100
drm/fb-helper: Perform all fbdev I/O with the same implementation
+ .fb_read= drm_fb_helper_cfb_read,
+ .fb_write = drm_fb_helper_cfb_write,
and now effectively those two changes are being reverted, so we'd
now be back to the pre-July 2015 state of affairs. As I believe
the fbdev layer has been stable, this change merely reverts the
driver back to what it once was.
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!
Re: [PATCH v2 02/12] drm/armada: Use regular fbdev I/O helpers
Hi Thomas,
On Mon, May 15, 2023 at 11:40:23AM +0200, Thomas Zimmermann wrote:
> Use the regular fbdev helpers for framebuffer I/O instead of DRM's
> helpers. Armada does not use damage handling, so DRM's fbdev helpers
> are mere wrappers around the fbdev code.
>
> By using fbdev helpers directly within each DRM fbdev emulation,
> we can eventually remove DRM's wrapper functions entirely.
>
> v2:
> * use FB_IO_HELPERS option
>
> Signed-off-by: Thomas Zimmermann
> Cc: Russell King
> ---
> drivers/gpu/drm/armada/Kconfig| 1 +
> drivers/gpu/drm/armada/armada_fbdev.c | 9 -
> 2 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/armada/Kconfig b/drivers/gpu/drm/armada/Kconfig
> index f5c66d89ba99..5afade25e217 100644
> --- a/drivers/gpu/drm/armada/Kconfig
> +++ b/drivers/gpu/drm/armada/Kconfig
> @@ -3,6 +3,7 @@ config DRM_ARMADA
> tristate "DRM support for Marvell Armada SoCs"
> depends on DRM && HAVE_CLK && ARM && MMU
> select DRM_KMS_HELPER
> + select FB_IO_HELPERS if DRM_FBDEV_EMULATION
> help
> Support the "LCD" controllers found on the Marvell Armada 510
> devices. There are two controllers on the device, each controller
> diff --git a/drivers/gpu/drm/armada/armada_fbdev.c
> b/drivers/gpu/drm/armada/armada_fbdev.c
> index 0a5fd1aa86eb..6c3bbaf53569 100644
> --- a/drivers/gpu/drm/armada/armada_fbdev.c
> +++ b/drivers/gpu/drm/armada/armada_fbdev.c
> @@ -5,6 +5,7 @@
> */
>
> #include
> +#include
> #include
> #include
>
> @@ -34,11 +35,9 @@ static void armada_fbdev_fb_destroy(struct fb_info *info)
> static const struct fb_ops armada_fb_ops = {
> .owner = THIS_MODULE,
> DRM_FB_HELPER_DEFAULT_OPS,
> - .fb_read= drm_fb_helper_cfb_read,
> - .fb_write = drm_fb_helper_cfb_write,
I had expected to see
.fb_read = fb_io_read,
But maybe this only used when using damage handling?
Likewise for drm_fb_helper_cfb_write.
??
> - .fb_fillrect= drm_fb_helper_cfb_fillrect,
> - .fb_copyarea= drm_fb_helper_cfb_copyarea,
> - .fb_imageblit = drm_fb_helper_cfb_imageblit,
> + .fb_fillrect= cfb_fillrect,
> + .fb_copyarea= cfb_copyarea,
> + .fb_imageblit = cfb_imageblit,
This part is as expected.
Sam
> .fb_destroy = armada_fbdev_fb_destroy,
> };
>
> --
> 2.40.1
[PATCH v2 02/12] drm/armada: Use regular fbdev I/O helpers
Use the regular fbdev helpers for framebuffer I/O instead of DRM's
helpers. Armada does not use damage handling, so DRM's fbdev helpers
are mere wrappers around the fbdev code.
By using fbdev helpers directly within each DRM fbdev emulation,
we can eventually remove DRM's wrapper functions entirely.
v2:
* use FB_IO_HELPERS option
Signed-off-by: Thomas Zimmermann
Cc: Russell King
---
drivers/gpu/drm/armada/Kconfig| 1 +
drivers/gpu/drm/armada/armada_fbdev.c | 9 -
2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/armada/Kconfig b/drivers/gpu/drm/armada/Kconfig
index f5c66d89ba99..5afade25e217 100644
--- a/drivers/gpu/drm/armada/Kconfig
+++ b/drivers/gpu/drm/armada/Kconfig
@@ -3,6 +3,7 @@ config DRM_ARMADA
tristate "DRM support for Marvell Armada SoCs"
depends on DRM && HAVE_CLK && ARM && MMU
select DRM_KMS_HELPER
+ select FB_IO_HELPERS if DRM_FBDEV_EMULATION
help
Support the "LCD" controllers found on the Marvell Armada 510
devices. There are two controllers on the device, each controller
diff --git a/drivers/gpu/drm/armada/armada_fbdev.c
b/drivers/gpu/drm/armada/armada_fbdev.c
index 0a5fd1aa86eb..6c3bbaf53569 100644
--- a/drivers/gpu/drm/armada/armada_fbdev.c
+++ b/drivers/gpu/drm/armada/armada_fbdev.c
@@ -5,6 +5,7 @@
*/
#include
+#include
#include
#include
@@ -34,11 +35,9 @@ static void armada_fbdev_fb_destroy(struct fb_info *info)
static const struct fb_ops armada_fb_ops = {
.owner = THIS_MODULE,
DRM_FB_HELPER_DEFAULT_OPS,
- .fb_read= drm_fb_helper_cfb_read,
- .fb_write = drm_fb_helper_cfb_write,
- .fb_fillrect= drm_fb_helper_cfb_fillrect,
- .fb_copyarea= drm_fb_helper_cfb_copyarea,
- .fb_imageblit = drm_fb_helper_cfb_imageblit,
+ .fb_fillrect= cfb_fillrect,
+ .fb_copyarea= cfb_copyarea,
+ .fb_imageblit = cfb_imageblit,
.fb_destroy = armada_fbdev_fb_destroy,
};
--
2.40.1
