Am 31.07.2014 12:23, schrieb Thierry Reding:
On Thu, Jul 31, 2014 at 10:57:55AM +0200, Andreas Färber wrote:
Am 31.07.2014 10:38, schrieb Ajay kumar:
With just the spring-bridge.v6 branch of your own tree, I am able to see bootup logo on Skate(a variant of spring which also contains ps8622). I have tried both exynos_defconfig and multi_v7_defconfig. I enable DRM, EXYNOS DRM, BRIDGE CHIPS, IOMMU, EXYNOS IOMMU in configs.
[...]
If you have something like simplefb enabled in addition to a DRM driver, then perhaps the DRM driver isn't properly taking over the framebuffer console.
So, with simplefb reverted in U-Boot and ...
* with just the v6 applied (...~2), I get only a black screen from Linux, no penguins, but the backlight seems on. System comes up okay, ssh available, and nothing stands out in dmesg.
* with the two iommu patches on top, something breaks badly, no backlight, no USB/network, system inaccessible.
I.e. U-Boot had no noticeable impact on these symptoms.
* with the iommu patches, but dp-controller, ps8622, panel commented out, I do get backlight but USB/network not working, system inaccessible.
With simplefb support in U-Boot and with just v6 applied, but dp-controller, ps8622, panel commented out, things work as well as before, i.e. this series has no bad side effects. Note that I never claimed Ajay's series were broken, just reported that things regressed for me from v4, which may well be DT-related.
The iommu patches interfere with my USB somehow (none or not all devices powered; with v4, plugging my wifi dongle led to oops but ethernet dongle worked, so not entirely new symptom), which is bad since my rootfs is on USB. The internal SDIO-connected Wifi is not enabled yet, so USB based network is my only alternative to a working display once we reach userspace.
Regards, Andreas