On 25/09/2024 09:55, Michel Dänzer wrote:
On 2024-09-24 16:02, Alex Deucher wrote:
On Fri, Sep 20, 2024 at 11:36 AM Jocelyn Falempe <jfalempe@xxxxxxxxxx> wrote:
On 17/09/2024 15:21, Alex Deucher wrote:
On Mon, Aug 12, 2024 at 2:10 AM Lu Yao <yaolu@xxxxxxxxxx> wrote:
Add support for the drm_panic module, which displays a pretty user
friendly message on the screen when a Linux kernel panic occurs.
Signed-off-by: Lu Yao <yaolu@xxxxxxxxxx>
Patch looks good to me. Any chance you want to convert the other
non-DC dce files (dce_v8_0.c, dce_v10_0.c, dce_v11_0.c) while you are
at it?
I've made a similar patch in amdgpu_dm_plane.c, and it works on a Radeon
pro w6400.
But it only works when I'm in a VT terminal (so the framebuffer is
linear and CPU accessible).
When under Gnome/Wayland, the flag AMDGPU_GEM_CREATE_NO_CPU_ACCESS is
set, so that means I can't vmap it ?
It just means that the application does not need CPU access. Whether
or not the CPU can access the buffer or not depends on the size of the
PCI BAR. E.g., if the driver or bios has resized the PCI BAR, then
the CPU can access the entire BAR, but if not you are generally
limited to the first 256M of framebuffer.
FWIW, it's also possible to access all of VRAM via MMIO indirect registers. That'll be slower than a direct CPU map, it might be acceptable for drm_panic though, at least as a fallback.
Thanks, I will try that too. For panic, we only need to write the
framebuffer once, so performances doesn't really matter.
I will try to use amdgpu_device_mm_access() for that.
--
Jocelyn
