[PATCH v2 5/5] drm/sun4i: dw-hdmi: Fix max. frequency for H6

From: Jernej Skrabec <jernej.skrabec@siol.net>
To: mripard@kernel.org, wens@csie.org
Cc: mturquette@baylibre.com, sboyd@kernel.org, airlied@linux.ie,
	daniel@ffwll.ch, linux-clk@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
	linux-sunxi@googlegroups.com, Andre Heider <a.heider@gmail.com>
Subject: [PATCH v2 5/5] drm/sun4i: dw-hdmi: Fix max. frequency for H6
Date: Mon,  8 Feb 2021 13:17:52 +0100	[thread overview]
Message-ID: <20210208121752.2255465-6-jernej.skrabec@siol.net> (raw)
In-Reply-To: <20210208121752.2255465-1-jernej.skrabec@siol.net>

It turns out that reasoning for lowering max. supported frequency is
wrong. Scrambling works just fine. Several now fixed bugs prevented
proper functioning, even with rates lower than 340 MHz. Issues were just
more pronounced with higher frequencies.

Fix that by allowing max. supported frequency in HW and fix the comment.

Fixes: cd9063757a22 ("drm/sun4i: DW HDMI: Lower max. supported rate for H6")
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Tested-by: Andre Heider <a.heider@gmail.com>
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
---
 drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
index 23773a5e0650..bbdfd5e26ec8 100644
--- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
+++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
@@ -47,11 +47,9 @@ sun8i_dw_hdmi_mode_valid_h6(struct dw_hdmi *hdmi, void *data,
 {
 	/*
 	 * Controller support maximum of 594 MHz, which correlates to
-	 * 4K@60Hz 4:4:4 or RGB. However, for frequencies greater than
-	 * 340 MHz scrambling has to be enabled. Because scrambling is
-	 * not yet implemented, just limit to 340 MHz for now.
+	 * 4K@60Hz 4:4:4 or RGB.
 	 */
-	if (mode->clock > 340000)
+	if (mode->clock > 594000)
 		return MODE_CLOCK_HIGH;
 
 	return MODE_OK;
-- 
2.30.0

