From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (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 0C97B18C91F; Mon, 28 Oct 2024 11:29:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730114957; cv=none; b=uSu+Zm0+tMLKZHnXva6kaaWEhV3TRE0H9hk4e/l5/SeJJeMjnZ2wC0DemYFAU085I3Y/cB/5rLBIO0ndoiNxmg46+tXRlZXXtRwVWE+xY0gSD4oWtZCThc4VFAt8F0onL7nYNRiy6Bb77zdEfSVGQ+aXCRrZWWX7LFdyMqaKRi4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730114957; c=relaxed/simple; bh=DCtJ5HW9wfc2GrhVDWw44uFxf+d5EMOaqW910++IUbM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=biSEGwiIUzWnM9zDVHf1rbL7s59FO0cs48Rb728IIIwonHLngkVmS56UFs01J0EnRGfRVQYbkJ5k8OCdCI9sBLr2waOQAzFkpkXK5sRSdBG1zvGxGmUDa43n7GS4heul/JI9mLT1pNeSrjWKtenMcra2IFHXGITAVqaJUUuZ7Ac= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=HzpyWrqP; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="HzpyWrqP" Received: from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi [81.175.209.231]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 487231A7D; Mon, 28 Oct 2024 12:29:02 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1730114942; bh=DCtJ5HW9wfc2GrhVDWw44uFxf+d5EMOaqW910++IUbM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HzpyWrqPopJ2t02+Kjy5R1wCQtBEhlazs51FpL4fwy+ifQai+4Tn+0+2U9yBPPpjG noE7Rxom/stFgPdM0uP+EgQmmOfgPbL8fyyhQ1a0fXcAM2Jc6vvvl7NM4JcnSZXq8U T8OMTb2hr/8KDzDys2XDcmQf0q4La34FGgNCBOHI= Date: Mon, 28 Oct 2024 13:28:57 +0200 From: Laurent Pinchart To: Herve Codina Cc: Andrzej Hajda , Neil Armstrong , Robert Foss , Jonas Karlman , Jernej Skrabec , David Airlie , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Marek Vasut , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Luca Ceresoli , Thomas Petazzoni Subject: Re: [PATCH 2/2] drm: bridge: ti-sn65dsi83: Add error recovery mechanism Message-ID: <20241028112857.GF24052@pendragon.ideasonboard.com> References: <20241024095539.1637280-1-herve.codina@bootlin.com> <20241024095539.1637280-3-herve.codina@bootlin.com> <20241027162350.GA15853@pendragon.ideasonboard.com> <20241028091331.6f67e29e@bootlin.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20241028091331.6f67e29e@bootlin.com> On Mon, Oct 28, 2024 at 09:13:31AM +0100, Herve Codina wrote: > Hi Laurent, > > On Sun, 27 Oct 2024 18:23:50 +0200 > Laurent Pinchart wrote: > > [...] > > > +static int sn65dsi83_reset_pipeline(struct sn65dsi83 *sn65dsi83) > > > +{ > > > + struct drm_device *dev = sn65dsi83->bridge.dev; > > > + struct drm_modeset_acquire_ctx ctx; > > > + struct drm_atomic_state *state; > > > + int err; > > > + > > > + /* Use operation done in drm_atomic_helper_suspend() followed by > > > + * operation done in drm_atomic_helper_resume() but without releasing > > > + * the lock between suspend()/resume() > > > + */ > > > + > > > + DRM_MODESET_LOCK_ALL_BEGIN(dev, ctx, 0, err); > > > + > > > + state = drm_atomic_helper_duplicate_state(dev, &ctx); > > > + if (IS_ERR(state)) { > > > + err = PTR_ERR(state); > > > + goto unlock; > > > + } > > > + > > > + err = drm_atomic_helper_disable_all(dev, &ctx); > > > + if (err < 0) > > > + goto unlock; > > > + > > > + drm_mode_config_reset(dev); > > > + > > > + err = drm_atomic_helper_commit_duplicated_state(state, &ctx); > > > > Committing a full atomic state from a bridge driver in an asynchronous > > way seems quite uncharted territory, and it worries me. It's also a very > > heavyweight, you disable all outputs here, instead of focussing on the > > output connected to the bridge. Can you either implement something more > > local, resetting the bridge only, or create a core helper to handle this > > kind of situation, on a per-output basis ? > > A full restart of the bridge (power off/on) is needed and so we need to > redo the initialization sequence. This initialization sequence has to be > done with the DSI data lanes (bridge inputs) driven in LP11 state and so > without any video stream. Only focussing on bridge outputs will not be > sufficient. That's why I brought the pipeline down and restarted it. Fair point. > Of course, I can copy/paste sn65dsi83_reset_pipeline() to a core helper > function. Is drm_atomic_helper_reset_all() could be a good candidate? The helper should operate on a single output, unrelated outputs should not be affected. -- Regards, Laurent Pinchart