From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BE82227F07 for ; Fri, 21 Jul 2023 18:57:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3B778C433C8; Fri, 21 Jul 2023 18:57:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689965847; bh=fHDODbcfyNgIg6RebuAaesGkZuSAi3NzOlRE61p1Vq4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TQV2rlN3uMPHhbli8M+U+C0+4kBWgizckM1q7a6MHG7/naz/O+wSDnrvYCNLKbkib Sx5h4gz39H6FAAhWjgD0SEJuZ9JRxRyvstF4qKk9x52jhl4TaUd1oBzB3qxEie7Xao OIEYxpuZyECKPYI2x1ybGqYpFerye8l/EmRylc6U= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Francesco Dolcini , Robert Foss , Sasha Levin Subject: [PATCH 5.15 107/532] drm/bridge: tc358768: fix THS_TRAILCNT computation Date: Fri, 21 Jul 2023 18:00:11 +0200 Message-ID: <20230721160620.379133634@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230721160614.695323302@linuxfoundation.org> References: <20230721160614.695323302@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Francesco Dolcini [ Upstream commit bac7842cd179572e8e0fc2d7b5254e40c6e9e057 ] Correct computation of THS_TRAILCNT register. This register must be set to a value that ensure that THS_TRAIL > 60 ns + 4 x UI and THS_TRAIL > 8 x UI and THS_TRAIL < TEOT with TEOT = 105 ns + (12 x UI) with the actual value of THS_TRAIL being (1 + THS_TRAILCNT) x ByteClk cycle + ((1 to 2) + 2) xHSBYTECLK cycle + - (PHY output delay) with PHY output delay being about (8 + (5 to 6)) x MIPIBitClk cycle in the BitClk conversion. Fixes: ff1ca6397b1d ("drm/bridge: Add tc358768 driver") Signed-off-by: Francesco Dolcini Reviewed-by: Robert Foss Signed-off-by: Robert Foss Link: https://patchwork.freedesktop.org/patch/msgid/20230427142934.55435-9-francesco@dolcini.it Signed-off-by: Sasha Levin --- drivers/gpu/drm/bridge/tc358768.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/bridge/tc358768.c b/drivers/gpu/drm/bridge/tc358768.c index c9c2e15c6f4a2..8b1bdffc5005d 100644 --- a/drivers/gpu/drm/bridge/tc358768.c +++ b/drivers/gpu/drm/bridge/tc358768.c @@ -763,9 +763,10 @@ static void tc358768_bridge_pre_enable(struct drm_bridge *bridge) dev_dbg(priv->dev, "TCLK_POSTCNT: 0x%x\n", val); tc358768_write(priv, TC358768_TCLK_POSTCNT, val); - /* 60ns + 4*UI < THS_PREPARE < 105ns + 12*UI */ - val = tc358768_ns_to_cnt(60 + tc358768_to_ns(15 * ui_nsk), - dsibclk_nsk) - 5; + /* max(60ns + 4*UI, 8*UI) < THS_TRAILCNT < 105ns + 12*UI */ + raw_val = tc358768_ns_to_cnt(60 + tc358768_to_ns(18 * ui_nsk), + dsibclk_nsk) - 4; + val = clamp(raw_val, 0, 15); dev_dbg(priv->dev, "THS_TRAILCNT: 0x%x\n", val); tc358768_write(priv, TC358768_THS_TRAILCNT, val); -- 2.39.2