linux-kernel - Re: [PATCH v3] drm/gma500: depend on framebuffer

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CADvTj4oyW1yfJhCC_yL2kehPJcSPCYXA2YZU44=oMr5K=6=pTw@mail.gmail.com>
Date:   Thu, 21 Apr 2022 13:24:20 -0500
From:   James Hilliard <james.hilliard1@...il.com>
To:     Thomas Zimmermann <tzimmermann@...e.de>
Cc:     Javier Martinez Canillas <javierm@...hat.com>,
        David Airlie <airlied@...ux.ie>,
        Randy Dunlap <rdunlap@...radead.org>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        dri-devel <dri-devel@...ts.freedesktop.org>
Subject: Re: [PATCH v3] drm/gma500: depend on framebuffer

On Thu, Apr 21, 2022 at 1:23 PM Thomas Zimmermann <tzimmermann@...e.de> wrote:
>
> Hi
>
> Am 21.04.22 um 20:22 schrieb Thomas Zimmermann:
> > Hi
> >
> > Am 21.04.22 um 19:39 schrieb James Hilliard:
> >> On Thu, Apr 21, 2022 at 8:22 AM Javier Martinez Canillas
> >> <javierm@...hat.com> wrote:
> >>>
> >>> On 4/21/22 14:54, Patrik Jakobsson wrote:
> >>>> On Thu, Apr 21, 2022 at 2:47 PM Javier Martinez Canillas
> >>>> <javierm@...hat.com> wrote:
> >>>
> >>> [snip]
> >>>
> >>>>>>>> diff --git a/drivers/gpu/drm/gma500/Kconfig
> >>>>>>>> b/drivers/gpu/drm/gma500/Kconfig
> >>>>>>>> index 0cff20265f97..a422fa84d53b 100644
> >>>>>>>> --- a/drivers/gpu/drm/gma500/Kconfig
> >>>>>>>> +++ b/drivers/gpu/drm/gma500/Kconfig
> >>>>>>>> @@ -2,11 +2,13 @@
> >>>>>>>>    config DRM_GMA500
> >>>>>>>>        tristate "Intel GMA500/600/3600/3650 KMS Framebuffer"
> >>>>>>>>        depends on DRM && PCI && X86 && MMU
> >>>>>>>> +     depends on FB
> >>>>>>>
> >>>>>>> Why do we need FB here? Framebuffer support should be hidden by
> >>>>>>> DRM's
> >>>>>>> fbdev helpers.
> >>>>>>
> >>>>>> It is not needed but gives him video output since it enables the drm
> >>>>>> fbdev emulation.
> >>>>>>
> >>>>>
> >>>>> I'm not sure to understand this. Shouldn't depend on
> >>>>> DRM_FBDEV_EMULATION then?
> >>>>
> >>>> No, it shouldn't depend on any FBDEV stuff since it's not actually
> >>>> required. It just happens to help in this case since weston + fbdev
> >>>> backend works but not weston with drm backend (or whatever config
> >>>> James have set).
> >>>
> >>> I see. Then the correct approach for them would be to just enable
> >>> CONFIG_FB
> >>> and DRM_FBDEV_EMULATION in their kernel config, rather than making
> >>> this to
> >>> depend on anything FB related as you said.
> >>
> >> Yeah, so it looks like CONFIG_FB_EFI is not needed but
> >> CONFIG_DRM_FBDEV_EMULATION is, I think I just assumed efifb
> >> was what was needed based on the kernel logs.
> >>
> >> This does not work:
> >> CONFIG_FB enabled
> >> CONFIG_DRM_FBDEV_EMULATION disabled
> >>
> >> This works:
> >> CONFIG_FB enabled
> >> CONFIG_DRM_FBDEV_EMULATION enabled
> >>
> >>>
> >>>>
> >>>>>
> >>>>>> I looked some more at the logs and it seems weston doesn't work on
> >>>>>> his
> >>>>>> system without the fbdev backend. So the question is why weston isn't
> >>>>>> working without fbdev? Perhaps this is just a Weston configuration
> >>>>>> issue?
> >>>>>>
> >>>>>
> >>>>> But is weston using the fbdev emulated by DRM or the one registered by
> >>>>> efifb? I thought that the latter from what was mentioned in this
> >>>>> thread.
> >>>>
> >>>> It's using drm fbdev emulation with gma500 so EFIFB has nothing to do
> >>>> with this. I believe it was just simply incorrectly reported. If I'm
> >>>> correct then "depends on FB" is what makes video output work for
> >>>> James.
> >>>>
> >>>
> >>> Got it. Thanks for the clarification.
> >>
> >> Here's my weston.ini:
> >> [core]
> >> shell=kiosk-shell.so
> >> modules=systemd-notify.so
> >> backend=drm-backend.so
> >> idle-time=0
> >> require-input=false
> >> use-pixman=true
> >>
> >> [shell]
> >> locking=false
> >> cursor-theme=Obsidian
> >> panel-position=none
> >>
> >> [output]
> >> name=DVI-D-1
> >> transform=rotate-270
> >>
> >> [output]
> >> name=DP-2
> >> mode=off
> >>
> >> [output]
> >> name=LVDS-1
> >> mode=off
> >
> > You mentioned that you want to use HDMI, but it's not configured here.
> > Is that intentionally?
>
> Nevermind. I just saw that DVI-D-1 is the HDMI port. (why?)

Not sure why the HDMI output is named DVI-D-1 but that's what
seems to configure it on this board.

>
> >
> > Best regards
> > Thomas
> >
> >>
> >> [libinput]
> >> touchscreen_calibrator=true
> >>
> >>>
> >>> --
> >>> Best regards,
> >>>
> >>> Javier Martinez Canillas
> >>> Linux Engineering
> >>> Red Hat
> >>>
> >
>
> --
> Thomas Zimmermann
> Graphics Driver Developer
> SUSE Software Solutions Germany GmbH
> Maxfeldstr. 5, 90409 Nürnberg, Germany
> (HRB 36809, AG Nürnberg)
> Geschäftsführer: Ivo Totev