[Dri-users] DRM/VC4: Problems with Linux 4.6

[Josef Raschen]

Hi,

I think I need some help to get the VC4 DRM running. I am using a Raspberry Pi 2 Model B, mainline Linux 4.6, the latest firmware blobs (bootcode.bin and start.elf) and u-boot 2016-05-rc3.

The bcm2835_defconfig is modified like this:

+CONFIG_PM=y
+CONFIG_IP_PNP=y
+CONFIG_IP_PNP_DHCP=y
-CONFIG_I2C=y
-CONFIG_FB=y
+CONFIG_DRM=y
+CONFIG_DRM_VC4=y
-CONFIG_FRAMEBUFFER_CONSOLE_DETECT_PRIMARY=y
-CONFIG_MMC_SDHCI_BCM2835=y
+CONFIG_MMC_SDHCI_IPROC=y
+CONFIG_ROOT_NFS=y
+CONFIG_NEON=y
+CONFIG_KERNEL_MODE_NEON=y

The device tree files in the mainline kernel are also still not updated for the VC4 driver, so I used this patch from the LKML:
https://lkml.org/lkml/2016/3/4/739

The kernel command line looks like this: earlyprintk cma=***@512M console=ttyAMA0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 rootwait

And then I try to run Weston, but this fails and I see the following messages on th kernel log:

[ 38.025629] vc4-drm soc:gpu: failed to allocate buffer with size 7057408
[ 38.032618] vc4-drm soc:gpu: failed to allocate buffer with size 7057408
[ 38.040431] [drm:vc4_bo_create] *ERROR* Failed to allocate from CMA:
[ 38.046868] [drm] num bos allocated: 4
[ 38.050767] [drm] size bos allocated: 7180kb
[ 38.055075] [drm] num bos used: 3
[ 38.058508] [drm] size bos used: 288kb
[ 38.062290] [drm] num bos cached: 1
[ 38.065858] [drm] size bos cached: 6892kb

Does anybody have an idea what is going on here?

Thanks,
Josef