Hi Am 28.07.22 um 13:13 schrieb Michael Ellerman:
Thomas Zimmermann <tzimmermann@xxxxxxx> writes:(was: drm: Add driverof PowerPC OF displays) PowerPC's Open Firmware offers a simple display buffer for graphics output. Add ofdrm, a DRM driver for the device. As with the existing simpledrm driver, the graphics hardware is pre-initialized by the firmware. The driver only provides blitting, no actual DRM modesetting is possible.Hi Thomas, I tried to test this on a 32-bit ppc Mac Mini but didn't have much luck.
Awesome! Thanks for testing.
But I'm probably doing something wrong because I'm a graphics noob. The machine normally uses CONFIG_DRM_RADEON, so I turned that off, and turned DRM_OFDRM on.
It needs CONFIG_DRM=y CONFIG_OFDRM=y CONFIG_FB=y CONFIG_DRM_FBDEV_EMULATION=yplus some dependencies, but menuconfig should select them automatically. I've attached my config for ppc64le, which has the correct DRM and FB options.
When I boot I get boot messages but only one screen worth, the messages don't scroll at all, which is unusual. But I'm not sure if that's related to ofdrm or something else. The machine does come up, I can login via SSH. Is there some way to start X to exercise the driver from an SSH login?
For ofdrm, X needs a patch that isn't there yet. It's a trivial change along the lines of [1], but still missing. So X is probably not worth trying yet.
But at least the framebuffer console should work.I suspect that it's an issue with the framebuffer's color mode, which might not be supported yet. Could you please fetch the output from dmesg after the machine booted?
Best regards Thomas[1] https://gitlab.freedesktop.org/xorg/xserver/-/commit/b9218fadf3c09d83566549279d68886d8258f79c
cheers
-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 Nürnberg, Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Ivo Totev
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