Am Sa, 24. Jun 2023, um 19:12, schrieb Markus Volk:
> Two pitfalls come to mind here
>
> It used to be necessary to use vc4-kms-v3d-pi4 dtbo. At some point this was
> changed so that even for the rpi4 only vc4-kms-v3d overlay had to be loaded
> and vc4-kms-v3d-pi4 was automatically reloaded. If your software version is
> old enough, using vc4-kms-v3d-pi4 dtoverlay might be necessary.
>
> kms relies completely on edid. fkms is more tolerant and often displays an
> image without a valid edid. I would therefore most likely guess a problem
> reading the edit information. Things I would try first are using a different
> HDMI cable or switching the hdmi port.
>
> On Sat, Jun 24 2023 at 06:02:52 PM +0200, Manuel Wagesreither
> <[email protected]> wrote:
>> Am Sa, 24. Jun 2023, um 17:25, schrieb Khem Raj:
>>> On Sat, Jun 24, 2023 at 7:47 AM Manuel Wagesreither <[email protected]>
>>> wrote:
>>>> Am Sa, 24. Jun 2023, um 00:04, schrieb Khem Raj:
>>>> > On Fri, Jun 23, 2023 at 2:39 PM Manuel Wagesreither <[email protected]>
>>>> > wrote:
>>>> >>
>>>> >> Hi users of meta-raspberrypi,
>>>> >>
>>>> >> I'd like to ask around if for you people vc4-kms-v3d (opposed to
>>>> >> vc4-fkms-v3d) *really* is the working way to get vc4 support on a
>>>> >> Raspberry Pi 4 Model B.
>>>> >>
>>>> >> Both on master and kirkstone, vc4-kms-v3d is the default. It's defined
>>>> >> in /conf/machine/raspberrypi4-64.conf:
>>>> >>
>>>> >> VC4DTBO ?= "vc4-kms-v3d"
>>>> >>
>>>> >> I was mildly surprised to find this, because on my system (running
>>>> >> Kirkstone) I can get the screen to work only if I specify vc4-fkms-v3d.
>>>> >>
>>>> >> Commit a6fa6b3aec36b92c3750852dd6788af9d2ce08f6 [1] broke my build. The
>>>> >> commit message further suggests that vc4-Fkms-v3d is broken, while
>>>> >> vc4-kms-v3d is not. So I'm wondering:hy is it exactly the other way
>>>> >> round on my machine?
>>>> >>
>>>> >> raspberrypi4: Use full kms (vc4-kms-v3d) DT overlay
>>>> >>
>>>> >> With latest 5.10 kernel fkms version fails to bring up VC4 and we
>>>> >> do not
>>>> >> get dri device initialized ( /dev/dri ) is empty, which means we
>>>> >> can not
>>>> >> launch wayland componsitors.
>>>> >>
>>>> >
>>>> > We have moved away from 5.10 kernel to 5.15 and then 6.1, so its
>>>> > possible that fkms is working fine again.
>>>> > If you test it with both vc4graphics and userland graphics do both work ?
>>>>
>>>> The meta-raspberrypi commit I'm on
>>>> (a6fa6b3aec36b92c3750852dd6788af9d2ce08f6) has recipes for Linux 5.10.110
>>>> and 5.15.34 and on both of them vc4-fkms-v3d works while vc4-kms-v3d does
>>>> not.
>>>>
>>>> * When using vc4-kms-v3d, the screen goes dark very early in the boot
>>>> process.
>>>> * When using vc4-kms-v3d, kmscube and weston-wayland both work.
>>>
>>> Which release branch are you using for
>>> Your project
>>
>> I'm two commits behind kirkstone, on meta-raspberrypi.
The HDMI port is unused on my raspi. I'm using the official Raspberry Pi 7"
Touchscreen connected via DSI.
Specifiying...
dtoverlay=vc4-kms-v3d
dtoverlay=vc4-kms-v3d-pi4
in config.txt doesn't change anything.
This is what both Linux 5.10.110 and 5.15.34 prints on the serial line:
(Screen is not working then.)
[ 1.400937] fb0: switching to vc4drmfb from simple
[ 1.402332] Console: switching to colour dummy device 80x25
[ 1.440694] vc4-drm gpu: bound fe400000.hvs (ops vc4_hvs_ops)
When specifying
dtoverlay=vc4-fkms-v3d
both Linux versions emit:
[ 1.387428] fb0: switching to vc4drmfb from simple
[ 1.388812] Console: switching to colour dummy device 80x25
[ 1.390196] vc4-drm gpu: bound fe600000.firmwarekms (ops vc4_fkms_ops)
[ 1.391001] [drm] Initialized vc4 0.0.0 20140616 for gpu on minor 0
[ 1.417292] Console: switching to colour frame buffer device 100x30
[ 1.433224] vc4-drm gpu: [drm] fb0: vc4drmfb frame buffer device
and provide a working screen.
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