The fbdev subsystem has a place for physical dimensions (width and height
in mm) that is readable by userspace. Since DRM also knows these
dimensions, pass this information to the fbdev device.
Signed-off-by: David Lechner <[email protected]>
---
drivers/gpu/drm/drm_fb_helper.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 574af01..07a6621 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1759,6 +1759,7 @@ void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helpe
uint32_t fb_width, uint32_t fb_height)
{
struct drm_framebuffer *fb = fb_helper->fb;
+ int i;
info->pseudo_palette = fb_helper->pseudo_palette;
info->var.xres_virtual = fb->width;
@@ -1771,6 +1772,18 @@ void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helpe
info->var.height = -1;
info->var.width = -1;
+ drm_fb_helper_for_each_connector(fb_helper, i) {
+ struct drm_connector *connector =
+ fb_helper->connector_info[i]->connector;
+
+ /* use the first connected connector for the physical dimensions */
+ if (connector->status == connector_status_connected) {
+ info->var.height = connector->display_info.width_mm;
+ info->var.width = connector->display_info.height_mm;
+ break;
+ }
+ }
+
switch (fb->format->depth) {
case 8:
info->var.red.offset = 0;
--
2.7.4
On Tue, Aug 01, 2017 at 10:26:41AM -0500, David Lechner wrote:
> The fbdev subsystem has a place for physical dimensions (width and height
> in mm) that is readable by userspace. Since DRM also knows these
> dimensions, pass this information to the fbdev device.
>
> Signed-off-by: David Lechner <[email protected]>
Still in the wrong function. Also please add some notation about what you
changed when resubmitting a patch (it took me a while to remember that I
replied to you already). That makes patch reviewing more efficient.
Thanks, Daniel
> ---
> drivers/gpu/drm/drm_fb_helper.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index 574af01..07a6621 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -1759,6 +1759,7 @@ void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helpe
> uint32_t fb_width, uint32_t fb_height)
> {
> struct drm_framebuffer *fb = fb_helper->fb;
> + int i;
>
> info->pseudo_palette = fb_helper->pseudo_palette;
> info->var.xres_virtual = fb->width;
> @@ -1771,6 +1772,18 @@ void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helpe
> info->var.height = -1;
> info->var.width = -1;
>
> + drm_fb_helper_for_each_connector(fb_helper, i) {
> + struct drm_connector *connector =
> + fb_helper->connector_info[i]->connector;
> +
> + /* use the first connected connector for the physical dimensions */
> + if (connector->status == connector_status_connected) {
> + info->var.height = connector->display_info.width_mm;
> + info->var.width = connector->display_info.height_mm;
> + break;
> + }
> + }
> +
> switch (fb->format->depth) {
> case 8:
> info->var.red.offset = 0;
> --
> 2.7.4
>
> _______________________________________________
> dri-devel mailing list
> [email protected]
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
On 08/02/2017 04:46 AM, Daniel Vetter wrote:
> On Tue, Aug 01, 2017 at 10:26:41AM -0500, David Lechner wrote:
>> The fbdev subsystem has a place for physical dimensions (width and height
>> in mm) that is readable by userspace. Since DRM also knows these
>> dimensions, pass this information to the fbdev device.
>>
>> Signed-off-by: David Lechner <[email protected]>
>
> Still in the wrong function. Also please add some notation about what you
> changed when resubmitting a patch (it took me a while to remember that I
> replied to you already). That makes patch reviewing more efficient.
>
Sorry for being so dense. :-/
I did read your first reply at least 10 times. All of the terminology is
foreign to me, but after sleeping on it a few days, I think it is slowly
soaking into my brain.
On Wed, Aug 2, 2017 at 6:37 PM, David Lechner <[email protected]> wrote:
> On 08/02/2017 04:46 AM, Daniel Vetter wrote:
>>
>> On Tue, Aug 01, 2017 at 10:26:41AM -0500, David Lechner wrote:
>>>
>>> The fbdev subsystem has a place for physical dimensions (width and height
>>> in mm) that is readable by userspace. Since DRM also knows these
>>> dimensions, pass this information to the fbdev device.
>>>
>>> Signed-off-by: David Lechner <[email protected]>
>>
>>
>> Still in the wrong function. Also please add some notation about what you
>> changed when resubmitting a patch (it took me a while to remember that I
>> replied to you already). That makes patch reviewing more efficient.
>>
>
> Sorry for being so dense. :-/
>
> I did read your first reply at least 10 times. All of the terminology is
> foreign to me, but after sleeping on it a few days, I think it is slowly
> soaking into my brain.
No problem, the code is fairly convoluted. One more question on your
v3: From reading fbdev code I don't see any place that overwrites the
physical dimensions except the fill_var helper function (which is
called deep down from register_framebuffer). If we entirely remove the
var.width/height assignments from that (including the -1 default) and
move all of it into setup_crtcs, would that work?
I kinda don't like have the same logic in 2 completely different
places, once for driver load and once for hotplug handling. That tends
to cause bugs (because then no one bothers to test hotplug handling or
the boot-up case properly).
Thanks, Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
On 08/02/2017 06:28 PM, Daniel Vetter wrote:
> On Wed, Aug 2, 2017 at 6:37 PM, David Lechner <[email protected]> wrote:
>> On 08/02/2017 04:46 AM, Daniel Vetter wrote:
>>>
>>> On Tue, Aug 01, 2017 at 10:26:41AM -0500, David Lechner wrote:
>>>>
>>>> The fbdev subsystem has a place for physical dimensions (width and height
>>>> in mm) that is readable by userspace. Since DRM also knows these
>>>> dimensions, pass this information to the fbdev device.
>>>>
>>>> Signed-off-by: David Lechner <[email protected]>
>>>
>>>
>>> Still in the wrong function. Also please add some notation about what you
>>> changed when resubmitting a patch (it took me a while to remember that I
>>> replied to you already). That makes patch reviewing more efficient.
>>>
>>
>> Sorry for being so dense. :-/
>>
>> I did read your first reply at least 10 times. All of the terminology is
>> foreign to me, but after sleeping on it a few days, I think it is slowly
>> soaking into my brain.
>
> No problem, the code is fairly convoluted. One more question on your
> v3: From reading fbdev code I don't see any place that overwrites the
> physical dimensions except the fill_var helper function (which is
> called deep down from register_framebuffer). If we entirely remove the
> var.width/height assignments from that (including the -1 default) and
> move all of it into setup_crtcs, would that work?
I tried that, but in my case, drm_setup_crtcs() is only called once
before the fbdev is allocated. So, I got a kernel oops from
dereferencing a null pointer, which is why there is a null check for
fb_helper->fbdev as part of the if statement I added there. Since
drm_setup_crtcs() is not called again, the var.width and height are
never set.
I also noticed that there is another similar workaround/code duplication
for the framebuffer not being allocated in the first call to
drm_setup_crtcs() seen at the end of drm_fb_helper_single_fb_probe().
>
> I kinda don't like have the same logic in 2 completely different
> places, once for driver load and once for hotplug handling. That tends
> to cause bugs (because then no one bothers to test hotplug handling or
> the boot-up case properly).
>
Would it be possible to split drm_setup_crtcs() into two functions, a
top half and a bottom half. During init (pseudo-code)...
drm_begin_setup_crtcs()
drm_fb_helper_single_fb_probe()
drm_finish_setup_crtcs()
and during hotplug event, just...
drm_begin_setup_crtcs()
drm_finish_crtcs_bottom_half()
I think it could solve both cases.
On Wed, Aug 02, 2017 at 08:37:56PM -0500, David Lechner wrote:
> On 08/02/2017 06:28 PM, Daniel Vetter wrote:
> > On Wed, Aug 2, 2017 at 6:37 PM, David Lechner <[email protected]> wrote:
> > > On 08/02/2017 04:46 AM, Daniel Vetter wrote:
> > > >
> > > > On Tue, Aug 01, 2017 at 10:26:41AM -0500, David Lechner wrote:
> > > > >
> > > > > The fbdev subsystem has a place for physical dimensions (width and height
> > > > > in mm) that is readable by userspace. Since DRM also knows these
> > > > > dimensions, pass this information to the fbdev device.
> > > > >
> > > > > Signed-off-by: David Lechner <[email protected]>
> > > >
> > > >
> > > > Still in the wrong function. Also please add some notation about what you
> > > > changed when resubmitting a patch (it took me a while to remember that I
> > > > replied to you already). That makes patch reviewing more efficient.
> > > >
> > >
> > > Sorry for being so dense. :-/
> > >
> > > I did read your first reply at least 10 times. All of the terminology is
> > > foreign to me, but after sleeping on it a few days, I think it is slowly
> > > soaking into my brain.
> >
> > No problem, the code is fairly convoluted. One more question on your
> > v3: From reading fbdev code I don't see any place that overwrites the
> > physical dimensions except the fill_var helper function (which is
> > called deep down from register_framebuffer). If we entirely remove the
> > var.width/height assignments from that (including the -1 default) and
> > move all of it into setup_crtcs, would that work?
>
>
> I tried that, but in my case, drm_setup_crtcs() is only called once before
> the fbdev is allocated. So, I got a kernel oops from dereferencing a null
> pointer, which is why there is a null check for fb_helper->fbdev as part of
> the if statement I added there. Since drm_setup_crtcs() is not called again,
> the var.width and height are never set.
fb_helper->fbdev is allocated in drm_fb_helper_alloc_fbi, which /should/
be called as the very first thing in setting up the entire fbdev stuff.
If you're oopsing on that, something went wrong. We also set info->var in
a few other places before calling register_framebuffer already (see the
line that sets info->var.pixclock right before calling
register_framebuffer).
> I also noticed that there is another similar workaround/code duplication for
> the framebuffer not being allocated in the first call to drm_setup_crtcs()
> seen at the end of drm_fb_helper_single_fb_probe().
>
> >
> > I kinda don't like have the same logic in 2 completely different
> > places, once for driver load and once for hotplug handling. That tends
> > to cause bugs (because then no one bothers to test hotplug handling or
> > the boot-up case properly).
> >
>
> Would it be possible to split drm_setup_crtcs() into two functions, a top
> half and a bottom half. During init (pseudo-code)...
>
> drm_begin_setup_crtcs()
> drm_fb_helper_single_fb_probe()
> drm_finish_setup_crtcs()
>
> and during hotplug event, just...
>
> drm_begin_setup_crtcs()
> drm_finish_crtcs_bottom_half()
>
> I think it could solve both cases.
I'm still not following where exactly and how you're blowing up. Can pls
paste the backtrace of how that all blows up?
Thanks, Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
On Thu, Aug 3, 2017 at 12:11 PM, Daniel Vetter <[email protected]> wrote:
> On Wed, Aug 02, 2017 at 08:37:56PM -0500, David Lechner wrote:
>> On 08/02/2017 06:28 PM, Daniel Vetter wrote:
>> > On Wed, Aug 2, 2017 at 6:37 PM, David Lechner <[email protected]> wrote:
>> > > On 08/02/2017 04:46 AM, Daniel Vetter wrote:
>> > > >
>> > > > On Tue, Aug 01, 2017 at 10:26:41AM -0500, David Lechner wrote:
>> > > > >
>> > > > > The fbdev subsystem has a place for physical dimensions (width and height
>> > > > > in mm) that is readable by userspace. Since DRM also knows these
>> > > > > dimensions, pass this information to the fbdev device.
>> > > > >
>> > > > > Signed-off-by: David Lechner <[email protected]>
>> > > >
>> > > >
>> > > > Still in the wrong function. Also please add some notation about what you
>> > > > changed when resubmitting a patch (it took me a while to remember that I
>> > > > replied to you already). That makes patch reviewing more efficient.
>> > > >
>> > >
>> > > Sorry for being so dense. :-/
>> > >
>> > > I did read your first reply at least 10 times. All of the terminology is
>> > > foreign to me, but after sleeping on it a few days, I think it is slowly
>> > > soaking into my brain.
>> >
>> > No problem, the code is fairly convoluted. One more question on your
>> > v3: From reading fbdev code I don't see any place that overwrites the
>> > physical dimensions except the fill_var helper function (which is
>> > called deep down from register_framebuffer). If we entirely remove the
>> > var.width/height assignments from that (including the -1 default) and
>> > move all of it into setup_crtcs, would that work?
>>
>>
>> I tried that, but in my case, drm_setup_crtcs() is only called once before
>> the fbdev is allocated. So, I got a kernel oops from dereferencing a null
>> pointer, which is why there is a null check for fb_helper->fbdev as part of
>> the if statement I added there. Since drm_setup_crtcs() is not called again,
>> the var.width and height are never set.
>
> fb_helper->fbdev is allocated in drm_fb_helper_alloc_fbi, which /should/
> be called as the very first thing in setting up the entire fbdev stuff.
> If you're oopsing on that, something went wrong. We also set info->var in
> a few other places before calling register_framebuffer already (see the
> line that sets info->var.pixclock right before calling
> register_framebuffer).
>
>> I also noticed that there is another similar workaround/code duplication for
>> the framebuffer not being allocated in the first call to drm_setup_crtcs()
>> seen at the end of drm_fb_helper_single_fb_probe().
Ok I screwed up, alloc_fbi is called from fb_probe, which is called
only from helper_single_probe(). Sorry about all my confusion, sounds
like we indeed have to duplicate this. Since the duplication is
necessary, can you pls extract an update_var static helper function,
which is called from both places? I'd put the call in
drm_fb_helper_hotplugt_event
and right before the register_framebuffer for the load path, not
trying to be clever like I suggested and hiding it somewhere in
drm_setup_crtcs.
Sorry for going all over the place with this, but fbdev isn't really
something I know all that well ...
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch