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 54BC81836CC for ; Sun, 23 Jun 2024 17:20:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719163246; cv=none; b=GNqVf1cs7iQ9kHZhPBhOXyCoGVNYUJW1PWNSL9FLjkPTJVkZcYyB7ZxMSzr1GC2Jc9yO/157DzI2M1MRnhwZar9y+lClK5L72R2F8J+m6HE7NG7Pqvi1EUmcip51C1nq2Sh1r70ELXVPYjAta09HioVkObFpunhICN3RYd7txws= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719163246; c=relaxed/simple; bh=2AmsLaNgIpfW4tk6T8sVQh3LyzJdjLq9qnkd69z21Po=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=lt5z1oxZ0XCqK2bfdKKPLprrRGUTzAqCryOmDeHthmJ2tkyt4WCePXjtfQPA3DT92UMsp34a/3seUG/o0JHopgwRZ+gJkJ13Q6HzFOWgZaxIjgvk99wVFQ5dT5ZFVmhzTdwcL+/9w0ae02iSlsVr73SF+XLCdV7Ev43FcXrpkmg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YmT8Zwn3; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="YmT8Zwn3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 57479C32786; Sun, 23 Jun 2024 17:20:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719163245; bh=2AmsLaNgIpfW4tk6T8sVQh3LyzJdjLq9qnkd69z21Po=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YmT8Zwn39Suc5haMGNZgk4v4ISIqE4iVLEX3AlK3vs1tAAT2hxNIxxSUD4XmaDw+V 5N6LC91VvUVtZ7pAlHgAexXq5WoMI3qn9EvwtmFqs86KhnvkYezZAQg3SX/ZS3Nm81 ZZqymuo2SN+ULCG90h/Y2ie8+MfM5QD4SsaNrLaXDFTXfJbYP4ElTqGtCZ5e9YlhkS aibOma1yRRrG+IJhOqztVEVUAlf8H2fQv6Y+/bO6yvKAg1BefSAquvWy6cDJFKemoZ vpaAMJK6TGxW0KtjbzYJyd7Vw+GACOPTWC5Ku6/PS8lsAWync1HMgIsHWnuOzyo5+N 7qkBjdGzQJNwg== Date: Sun, 23 Jun 2024 18:20:40 +0100 From: Conor Dooley To: Marek Vasut Cc: dri-devel@lists.freedesktop.org, Andrzej Hajda , Conor Dooley , Daniel Vetter , David Airlie , Jernej Skrabec , Jonas Karlman , Krzysztof Kozlowski , Laurent Pinchart , Lucas Stach , Maarten Lankhorst , Maxime Ripard , Neil Armstrong , Rob Herring , Robert Foss , Thomas Zimmermann , devicetree@vger.kernel.org, kernel@dh-electronics.com Subject: Re: [PATCH v2 1/2] dt-bindings: display: bridge: tc358867: Document default DP preemphasis Message-ID: <20240623-unadorned-human-deedc8fd4819@spud> References: <20240621155430.92894-1-marex@denx.de> <20240622-ruse-stock-2c2b8d0b1cfb@spud> <8d6bc5d3-6a21-4b90-a5f2-74b5597ba3b2@denx.de> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="yzBqMuf10iA8ZrEG" Content-Disposition: inline In-Reply-To: <8d6bc5d3-6a21-4b90-a5f2-74b5597ba3b2@denx.de> --yzBqMuf10iA8ZrEG Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Jun 23, 2024 at 04:48:47PM +0200, Marek Vasut wrote: > On 6/22/24 1:56 PM, Conor Dooley wrote: > > On Fri, Jun 21, 2024 at 05:53:53PM +0200, Marek Vasut wrote: > > > Document default DP port preemphasis configurable via new DT property > > > "toshiba,pre-emphasis". This is useful in case the DP link properties > > > are known and starting link training from preemphasis setting of 0 dB > > > is not useful. The preemphasis can be set separately for both DP lanes > > > in range 0=3D0dB, 1=3D3.5dB, 2=3D6dB . > > >=20 > > > Signed-off-by: Marek Vasut > > > --- > > > V2: - Fix the type to u8 array > > > - Fix the enum items to match what they represent > > > --- > > > .../display/bridge/toshiba,tc358767.yaml | 18 +++++++++++++++= +++ > > > 1 file changed, 18 insertions(+) > > >=20 > > > diff --git a/Documentation/devicetree/bindings/display/bridge/toshiba= ,tc358767.yaml b/Documentation/devicetree/bindings/display/bridge/toshiba,t= c358767.yaml > > > index 2ad0cd6dd49e0..6287eb2b40908 100644 > > > --- a/Documentation/devicetree/bindings/display/bridge/toshiba,tc3587= 67.yaml > > > +++ b/Documentation/devicetree/bindings/display/bridge/toshiba,tc3587= 67.yaml > > > @@ -98,6 +98,24 @@ properties: > > > reference to a valid eDP panel input endpoint node. Thi= s port is > > > optional, treated as DP panel if not defined > > > + properties: > > > + endpoint: > > > + $ref: /schemas/media/video-interfaces.yaml# > > > + unevaluatedProperties: false > > > + > > > + properties: > > > + toshiba,pre-emphasis: > > > + description: > > > + Display port output Pre-Emphasis settings for both= ports. > >=20 > > Why here and not in the port nodes? >=20 > There was a short discussion about that in V1: >=20 > https://lore.kernel.org/all/00e9ef90-3bbe-4556-8da9-462f65928781@denx.de/ >=20 > " > Let's keep it in the endpoint node. >=20 > There is some mention in the TC9595 datasheet that the DP might operate > in some split mode, where each DP lane is used to feed one display (?), > so I assume in that case there might be two endpoints (?), but that is > not supported right now. >=20 > If that is ever needed, I guess this array would have minItems 1 and > maxItems 2 and another endpoint would be added to the schema for this > port 2. > " Can this be put in the commit message please? > > > + $ref: /schemas/types.yaml#/definitions/uint8-array > > > + minItems: 2 > > > + maxItems: 2 > > > + items: > > > + enum: > > > + - 0 # No pre-emphasis > > > + - 1 # 3.5dB pre-emphasis > > > + - 2 # 6dB pre-emphasis > >=20 > > I'd love to say please make this -bB and put this in units, but that'd > > require it being a string.. >=20 > I can do that. Do you think that's worth it ? I dunno, I'd advocate for it for any other unit cos I would ask for the unit to be changed into something that didn't require fractions. But for decibels, that just going to be confusing given how it works. I think for dB it's just not worth it. --yzBqMuf10iA8ZrEG Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCZnhZaAAKCRB4tDGHoIJi 0rdQAQDr9zyqpYxL8AhLMhCi0G6rabJ9c5NGz4sygSDIEkDwUgEAgJHtE2XxX5cY q+lSwvwXRAoJW4vw2dWK514Qz7zwFw0= =Jp6p -----END PGP SIGNATURE----- --yzBqMuf10iA8ZrEG--