drm/hibmc: Fix list of formats on the primary plane

Remove all formats from the primary plane that are unsupported for
various reasons.

* Formats with alpha channel: planes should not announce alpha channels
unless they support transparency. There's no transparency support in
the primary plane's implementation.

* Formats with BGR order. The common format is in RGB channel order.
There's no BGR support in the primary plane's implementation.

* RGB888: atomic_update programs the format from cpp[0] * 8 / 16. For
RGB888's cpp value of 3 this returns 1.5; rounded to 1. Programming
the value of 1 to HIBMC_CRT_DISP_CTL_FORMAT sets up RGB565. Hence, the
output is distorted. This can be tested by booting with video=1024x768-24.

Removing all unsupported formats leaves XRGB8888 and RGB565. Both of
which are supported and work correctly.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: da52605eea ("drm/hisilicon/hibmc: Add support for display engine")
Reviewed-by: Yongbang Shi <shiyongbang@huawei.com>
Cc: Rongrong Zou <zourongrong@gmail.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Xinliang Liu <xinliang.liu@linaro.org>
Cc: Dmitry Baryshkov <lumag@kernel.org>
Cc: Yongbang Shi <shiyongbang@huawei.com>
Cc: Baihan Li <libaihan@huawei.com>
Cc: <stable@vger.kernel.org> # v4.10+
Link: https://patch.msgid.link/20260618123142.92298-3-tzimmermann@suse.de
This commit is contained in:
Thomas Zimmermann 2026-06-18 14:28:40 +02:00
commit 0e682e136c