From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 198D4C4332F for ; Sat, 15 Oct 2022 17:14:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229673AbiJOROG (ORCPT ); Sat, 15 Oct 2022 13:14:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60670 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229519AbiJOROF (ORCPT ); Sat, 15 Oct 2022 13:14:05 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75AB048A38 for ; Sat, 15 Oct 2022 10:14:04 -0700 (PDT) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 9FCF7480; Sat, 15 Oct 2022 19:14:01 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1665854041; bh=mlExtG3PX3BfXsQGa88t7dxFY/1l+czRQhArSgZe9Do=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HZshcaZbPpeYrYKHrCqfYrfyJ0oMng/IGit7wXLru3zGYdIgD4Y9eTtYU14rr0rIt C9RRISG4SlPoz87rLi6p96KyGxLd9EO3dR6pgPgCT0eB20oiovZsTzUKv7dsl5bIIY quHMKLNAjEMp6uUhyHduCf0LmOHGJdKiClKMTtks= Date: Sat, 15 Oct 2022 20:13:38 +0300 From: Laurent Pinchart To: Maxime Ripard Cc: Maxime Ripard , Eric Anholt , Daniel Vetter , David Airlie , Rob Herring , Emma Anholt , dri-devel@lists.freedesktop.org, Joerg Quinten , Chris Morgan , Dave Stevenson , linux-kernel@vger.kernel.org Subject: Re: [PATCH 6/7] drm/vc4: dpi: Change the default DPI format to being 18bpp, not 24. Message-ID: References: <20221013-rpi-dpi-improvements-v1-0-8a7a96949cb0@cerno.tech> <20221013-rpi-dpi-improvements-v1-6-8a7a96949cb0@cerno.tech> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20221013-rpi-dpi-improvements-v1-6-8a7a96949cb0@cerno.tech> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Maxime (and Dave), Thank you for the patch. On Thu, Oct 13, 2022 at 11:56:50AM +0200, Maxime Ripard wrote: > From: Dave Stevenson > > DPI hasn't really been used up until now, so the default has > been meaningless. > In theory we should be able to pass the desired format for the > adjacent bridge chip through, but framework seems to be missing > for that. Doesn't the bridge infrastructure allow that ? Or maybe this commit message was written a while ago, before it was possible ? In any case, it would be nice to use the bus format exposed by the next bridge in the chain, but that can be done in a subsequent step. The new default seems reasonable. Reviewed-by: Laurent Pinchart > As the main device to use DPI is the VGA666 or Adafruit Kippah, > both of which use RGB666, change the default to being RGB666 instead > of RGB888. > > Signed-off-by: Dave Stevenson > Signed-off-by: Maxime Ripard > --- > drivers/gpu/drm/vc4/vc4_dpi.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/vc4/vc4_dpi.c b/drivers/gpu/drm/vc4/vc4_dpi.c > index ecbe4cd87036..fdae02760b6d 100644 > --- a/drivers/gpu/drm/vc4/vc4_dpi.c > +++ b/drivers/gpu/drm/vc4/vc4_dpi.c > @@ -150,8 +150,8 @@ static void vc4_dpi_encoder_enable(struct drm_encoder *encoder) > } > drm_connector_list_iter_end(&conn_iter); > > - /* Default to 24bit if no connector or format found. */ > - dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, DPI_FORMAT); > + /* Default to 18bit if no connector or format found. */ > + dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1, DPI_FORMAT); > > if (connector) { > if (connector->display_info.num_bus_formats) { > -- Regards, Laurent Pinchart