From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lelvem-ot01.ext.ti.com (lelvem-ot01.ext.ti.com [198.47.23.234]) (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 00E8F227581 for ; Thu, 24 Apr 2025 10:47:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.47.23.234 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745491645; cv=none; b=MqBoPQjtRm+wlyKjiCY19ln1Pw5qW6ys9Dk/w1meKVvFbD5ghMrZDt4PSpPxfAXDZrII0T7p2uQgbPEV7qUBLooPdAk3Sa6BM4KMk4pODTjnVfoC1two9RqAZqyCeWM8iXVn9GKaBEut61qFiousCC/6roTlSuoBXWxdirGj0t0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745491645; c=relaxed/simple; bh=rXm85CIlHrNq9qgdiuCvVcSM3qP9rnxicDeaNAhBC7w=; h=Message-ID:Date:MIME-Version:Subject:From:To:CC:References: In-Reply-To:Content-Type; b=IpL9rtlKXT3FN0sQwc9xMFH//YYgVNEi4MahGEhJGplbenHCE8a62jD7nEtOeAD43ilwBCjWnUWf/yaGzecu7XpiRYSox4sTWIe3Fc6xSWMfhZ0r6txFOzGt9ZcyHWbiHXWakFgGQm2EH27vzXPVtZiV1iGIrx9QMhRcGEcsYok= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com; spf=pass smtp.mailfrom=ti.com; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b=e8s1BmGY; arc=none smtp.client-ip=198.47.23.234 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ti.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="e8s1BmGY" Received: from fllv0035.itg.ti.com ([10.64.41.0]) by lelvem-ot01.ext.ti.com (8.15.2/8.15.2) with ESMTPS id 53OAl4Y31836161 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 24 Apr 2025 05:47:04 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1745491624; bh=jh4FnYk80pv2AQJY2LMZ461mxQWUhiwR+r0euZp7KRM=; h=Date:Subject:From:To:CC:References:In-Reply-To; b=e8s1BmGYjdmOm7+v+3DYNuWrqpEErmUKYVoiHmc9cYRrV4tvhGv1x3sQuV2t+e/sX QGodd3a23yvkERvg0KY8C+LHR9TyCURyEt+RKpM6ktrdmHL1Ka8DMH3T8qzGs/8U/Y M+XGr6sfzVtf8+D6wwObAa/LnU0Dz5adkhRI/nss= Received: from DLEE109.ent.ti.com (dlee109.ent.ti.com [157.170.170.41]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 53OAl3jr012357 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 24 Apr 2025 05:47:03 -0500 Received: from DLEE100.ent.ti.com (157.170.170.30) by DLEE109.ent.ti.com (157.170.170.41) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Thu, 24 Apr 2025 05:47:02 -0500 Received: from lelvsmtp5.itg.ti.com (10.180.75.250) by DLEE100.ent.ti.com (157.170.170.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Thu, 24 Apr 2025 05:47:02 -0500 Received: from [10.24.72.182] (jayesh-hp-z2-tower-g5-workstation.dhcp.ti.com [10.24.72.182]) by lelvsmtp5.itg.ti.com (8.15.2/8.15.2) with ESMTP id 53OAkwR2066159; Thu, 24 Apr 2025 05:46:59 -0500 Message-ID: <526c1714-95f1-49ea-9bf1-a778e00ad6bf@ti.com> Date: Thu, 24 Apr 2025 16:16:58 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] drm/bridge: ti-sn65dsi86: Add necessary DSI flags From: Jayesh Choudhary To: Doug Anderson CC: , , , , , , , , , , , , References: <20250411092307.238398-1-j-choudhary@ti.com> Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-C2ProcessedOrg: 333ef613-75bf-4e12-a4b1-8e3623f5dcea Hello Doug, On 17/04/25 02:40, Jayesh Choudhary wrote: > Hello Doug, > > On 13/04/25 07:22, Doug Anderson wrote: >> Hi, >> >> On Fri, Apr 11, 2025 at 2:23 AM Jayesh Choudhary >> wrote: >>> >>> Enable NO_EOT and SYNC flags for DSI to use VIDEO_SYNC_PULSE_MODE >>> with EOT disabled. >> >> Any chance you could add some details to this commit message? Your >> subject says that these flags are "necessary", but people have been >> using this driver successfully for many years now. Why did these flags >> suddenly become necessary and why were things working before? >> >> I'm not saying that we shouldn't use these flags, just trying to >> understand. I actually don't know a ton about these details in MIPI, >> so it would help me :-). >> > > Definitely. > I will add more details for the commit message. > > For more context here, I was working with cadence dsi driver for TI > SoCs. So to be more accurate, this is required for CDNS_DSI > > I observed other bridges like lt-9211, where I have seen such flags > being set for dsi-controller by vendors. Upon testing with modes other than video sync pulse mode, I found that with the upcoming fixes in cdns-dsi-core driver made by Tomi[0], this patch is no longer necessary. [0]: https://lore.kernel.org/all/20250414-cdns-dsi-impro-v3-0-4e52551d4f07@ideasonboard.com/ I apologies for the noise in the mailing list. Warm Regards, Jayesh > >> >>> Signed-off-by: Jayesh Choudhary >>> --- >>>   drivers/gpu/drm/bridge/ti-sn65dsi86.c | 3 ++- >>>   1 file changed, 2 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c >>> b/drivers/gpu/drm/bridge/ti-sn65dsi86.c >>> index f72675766e01..8e9a7eb927da 100644 >>> --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c >>> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c >>> @@ -707,7 +707,8 @@ static int ti_sn_attach_host(struct >>> auxiliary_device *adev, struct ti_sn65dsi86 >>>          /* TODO: setting to 4 MIPI lanes always for now */ >>>          dsi->lanes = 4; >>>          dsi->format = MIPI_DSI_FMT_RGB888; >>> -       dsi->mode_flags = MIPI_DSI_MODE_VIDEO; >>> +       dsi->mode_flags = MIPI_DSI_MODE_VIDEO | >>> MIPI_DSI_MODE_NO_EOT_PACKET | >>> +                         MIPI_DSI_MODE_VIDEO_SYNC_PULSE; >> >> FWIW, I can confirm that on my board the screen still seems to light >> up after this change. ...so I'd be OK w/ >> >> Tested-by: Douglas Anderson >> >> ...before giving a Reviewed-by I'd want a description that helps me >> understand it better. > >> >> -Doug