diff mbox series

[v3,04/14] drm/mediatek: Fix XRGB setting error in Mixer

Message ID 20240620-igt-v3-4-a9d62d2e2c7e@mediatek.com (mailing list archive)
State New
Headers show
Series This series fixes the errors of MediaTek display driver found by IGT. | expand

Commit Message

Hsiao Chien Sung via B4 Relay June 19, 2024, 4:38 p.m. UTC 
From: Hsiao Chien Sung <shawn.sung@mediatek.com>

Although the alpha channel in XRGB formats can be ignored, ALPHA_CON
must be configured accordingly when using XRGB formats or it will still
affects CRC generation.

Fixes: d886c0009bd0 ("drm/mediatek: Add ETHDR support for MT8195")
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Hsiao Chien Sung <shawn.sung@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_ethdr.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

Comments

Markus Elfring Oct. 7, 2024, 11:36 a.m. UTC | #1 
> Although the alpha channel in XRGB formats can be ignored, ALPHA_CON
> must be configured accordingly when using XRGB formats or it will still
> affects CRC generation.

  affect?


Can such a change description become a bit nicer with an additional
imperative wording?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.12-rc2#n94

Regards,
Markus
Shawn Sung (宋孝謙) Oct. 9, 2024, 6:27 a.m. UTC | #2 
On Mon, 2024-10-07 at 13:36 +0200, Markus Elfring wrote:
> > Although the alpha channel in XRGB formats can be ignored,
> > ALPHA_CON
> > must be configured accordingly when using XRGB formats or it will
> > still
> > affects CRC generation.
> 
>   affect?

Yes, didn't notice that.
This is a typo, but the series has been merged.

> 
> 
> Can such a change description become a bit nicer with an additional
> imperative wording?
> 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.12-rc2#n94

Honestly, I wasn't familiar with the term "imerative mood" before this.
After studying it, I now understand. Thank you for pointing this out; I
will keep this in mind for the future.

As a result, I asked AI to refine the description using imperative
wording as a reference example:

"Ensure that ALPHA_CON is configured appropriately when using XRGB
formats, even though the alpha channel can be ignored. Failing to do so
will affect CRC generation."

Regards,
Shawn
> 
> Regards,
> Markus
diff mbox series

Patch

diff --git a/drivers/gpu/drm/mediatek/mtk_ethdr.c b/drivers/gpu/drm/mediatek/mtk_ethdr.c
index d7d16482c947..5c52e514ae30 100644
--- a/drivers/gpu/drm/mediatek/mtk_ethdr.c
+++ b/drivers/gpu/drm/mediatek/mtk_ethdr.c
@@ -153,6 +153,7 @@  void mtk_ethdr_layer_config(struct device *dev, unsigned int idx,
 	unsigned int offset = (pending->x & 1) << 31 | pending->y << 16 | pending->x;
 	unsigned int align_width = ALIGN_DOWN(pending->width, 2);
 	unsigned int alpha_con = 0;
+	bool replace_src_a = false;
 
 	dev_dbg(dev, "%s+ idx:%d", __func__, idx);
 
@@ -167,7 +168,15 @@  void mtk_ethdr_layer_config(struct device *dev, unsigned int idx,
 	if (state->base.fb && state->base.fb->format->has_alpha)
 		alpha_con = MIXER_ALPHA_AEN | MIXER_ALPHA;
 
-	mtk_mmsys_mixer_in_config(priv->mmsys_dev, idx + 1, alpha_con ? false : true,
+	if (state->base.fb && !state->base.fb->format->has_alpha) {
+		/*
+		 * Mixer doesn't support CONST_BLD mode,
+		 * use a trick to make the output equivalent
+		 */
+		replace_src_a = true;
+	}
+
+	mtk_mmsys_mixer_in_config(priv->mmsys_dev, idx + 1, replace_src_a,
 				  MIXER_ALPHA,
 				  pending->x & 1 ? MIXER_INX_MODE_EVEN_EXTEND :
 				  MIXER_INX_MODE_BYPASS, align_width / 2 - 1, cmdq_pkt);