Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Paul Cercueil <paul@crapouillou.net>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        "H . Nikolaus Schaller" <hns@goldelico.com>
Subject: [PATCH 5.12 176/242] drm/ingenic: Fix pixclock rate for 24-bit serial panels
Date:   Thu, 15 Jul 2021 20:38:58 +0200
Message-Id: <20210715182624.203982376@linuxfoundation.org>
In-Reply-To: <20210715182551.731989182@linuxfoundation.org>
References: <20210715182551.731989182@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Paul Cercueil <paul@crapouillou.net>

commit 60a6b73dd821e98fe958b2a83393ccd724b306b1 upstream.

When using a 24-bit panel on a 8-bit serial bus, the pixel clock
requested by the panel has to be multiplied by 3, since the subpixels
are shifted sequentially.

The code (in ingenic_drm_encoder_atomic_check) already computed
crtc_state->adjusted_mode->crtc_clock accordingly, but clk_set_rate()
used crtc_state->adjusted_mode->clock instead.

Fixes: 28ab7d35b6e0 ("drm/ingenic: Properly compute timings when using a 3x8-bit panel")
Cc: stable@vger.kernel.org # v5.10
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: H. Nikolaus Schaller <hns@goldelico.com>	# CI20/jz4780 (HDMI) and Alpha400/jz4730 (LCD)
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323144008.166248-1-paul@crapouillou.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/ingenic/ingenic-drm-drv.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
+++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
@@ -341,7 +341,7 @@ static void ingenic_drm_crtc_atomic_flus
 	if (priv->update_clk_rate) {
 		mutex_lock(&priv->clk_mutex);
 		clk_set_rate(priv->pix_clk,
-			     crtc_state->adjusted_mode.clock * 1000);
+			     crtc_state->adjusted_mode.crtc_clock * 1000);
 		priv->update_clk_rate = false;
 		mutex_unlock(&priv->clk_mutex);
 	}