[PATCH 4/6] staging: drm/imx: Add i.MX IPUv3 crtc support
Sascha Hauer
s.hauer at pengutronix.de
Sat Sep 22 06:17:27 EDT 2012
Hi Eric,
On Fri, Sep 21, 2012 at 09:24:19AM -0700, Eric Nelson wrote:
> Hi Sascha,
>
> While testing against a video-enabled U-Boot on i.MX6, I found the issue
> below.
>
[...]
>
> But ipu_crtc->imx_crtc gets initialized in this call, and
> ipu_irq_handler() makes use of it.
>
> The U-Boot code doesn't enable interrupts, so it's not acking
> along the way, and leaves bits set in IPU1_INT_STAT_15.
>
> I found that I can get around this in U-Boot by disabling the
> LCD controller and acking all of the interrupts after disabling
> the controller, but I haven't yet figured out where to tap into
> cleanup_before_linux().
Passing over an enabled IPU from the bootloader to the kernel is
(currently) not a supported usecase, so U-Boot should indeed disable it.
That said, the kernel driver should make sure the IPU is sufficiently
configured before the interrupts are enabled, so this seems to be a bug
that deserves fixing.
Sascha
--
Pengutronix e.K. | |
Industrial Linux Solutions | http://www.pengutronix.de/ |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
More information about the linux-arm-kernel
mailing list