From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.19]) (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 AC5BA299949; Wed, 17 Sep 2025 10:10:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758103810; cv=none; b=FQIvQ+grOMpHR1+2YGbqYH9bkOfT+xKK1rAsgv7IOC53BaknYDhq6Mi5fD9F/Haf0sntLivdAJkP5/XznG6mLB2YC+hQdE9wGgC1vjMq1r0EIVqGe8PclLfuoBG4s8UU1sAQyE5xzg/shqomdNx76ovX1m/XBdaIl0bgTYo2eL8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758103810; c=relaxed/simple; bh=2BpR/sbRSS7JegXJBjXVzWbl6vChgq/HKCHbYvwrI7U=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rKbwJT9et+dd9t8CF4HGZGH7jGH2SOxMH7uuV0ib8SS7BLvlTyhMZJNaM4xK547IO5qisQmrKZTIZcJN8gkjSkeOU5t75KTj7cPp+0SQacAwcFSr1eFdm7RB9aQZFrCdd/WbqnZq3owwkbrNDCIKcrrm5bij7aSCgNrCQJP3xEw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=k14ze+iu; arc=none smtp.client-ip=198.175.65.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="k14ze+iu" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1758103809; x=1789639809; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=2BpR/sbRSS7JegXJBjXVzWbl6vChgq/HKCHbYvwrI7U=; b=k14ze+iumj9o32ZKto+4r/sdLeBwGsc5kCaQGVl6Oq0gWTGoL6zaU7qS rimwdpfYE21h14DkUedkQahaDQlGwoll26pNVxASR/jW4mufpIPPC2IOs TXwr01K1N9IP2iv+1JPH8yRBYHV5qPaCX3xzPI9z1RJhoD7R/Mg8YwvwT wchFpjeo8XkNjrxpzRZFFbH5rngAZBIlCxkBUFMstSjsn5l5x+y6AnC0Y 2XgtLFAilhuoqSGktjmia9v3ShoPaClRfHrgcTddW2lvQOvPSVv+2VYi8 52ODjq4soVdyn39BgmRZa+YR7k5GXVSrQXRcNEgocxKD5KuvLEM5DPnC7 w==; X-CSE-ConnectionGUID: 2ppPnF1nRRK1bOab9oygBQ== X-CSE-MsgGUID: DV8LeAXhQAmpfFZOEBN6Cw== X-IronPort-AV: E=McAfee;i="6800,10657,11555"; a="60273889" X-IronPort-AV: E=Sophos;i="6.18,271,1751266800"; d="scan'208";a="60273889" Received: from fmviesa010.fm.intel.com ([10.60.135.150]) by orvoesa111.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Sep 2025 03:10:08 -0700 X-CSE-ConnectionGUID: C+/Qdhs4RR+Xg+pgupSnIw== X-CSE-MsgGUID: 2vCrjiHCSjOEzB3SgWbGbg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.18,271,1751266800"; d="scan'208";a="175980728" Received: from cpetruta-mobl1.ger.corp.intel.com (HELO kekkonen.fi.intel.com) ([10.245.244.41]) by fmviesa010-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Sep 2025 03:10:04 -0700 Received: from kekkonen.localdomain (localhost [IPv6:::1]) by kekkonen.fi.intel.com (Postfix) with ESMTP id 6911511FC22; Wed, 17 Sep 2025 13:10:02 +0300 (EEST) Date: Wed, 17 Sep 2025 13:10:02 +0300 Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo From: Sakari Ailus To: Val Packett Cc: =?iso-8859-1?Q?Andr=E9?= Apitzsch , Mauro Carvalho Chehab , Rob Herring , Krzysztof Kozlowski , Conor Dooley , devicetree@vger.kernel.org, Daniel Scally , ~postmarketos/upstreaming@lists.sr.ht, phone-devel@vger.kernel.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 7/7] media: i2c: dw9719: Fix power on/off sequence Message-ID: References: <20250817-dw9719-v1-0-426f46c69a5a@apitzsch.eu> <20250817-dw9719-v1-7-426f46c69a5a@apitzsch.eu> <550f28a9aa82a28beb35fd3490dbe08928ba9eed.camel@apitzsch.eu> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Hi André, Val, On Tue, Sep 16, 2025 at 05:08:44PM -0300, Val Packett wrote: > > On 9/15/25 5:48 PM, André Apitzsch wrote: > > Hi Sakari, > > > > @Val, please see below. > > > > Am Montag, dem 18.08.2025 um 07:44 +0000 schrieb Sakari Ailus: > > > Hi André, > > > > > > On Sun, Aug 17, 2025 at 07:09:26PM +0200, André Apitzsch via B4 Relay > > > wrote: > > > >   u64 val; > > > >   int ret; > > > >   int err; > > > > @@ -109,13 +116,15 @@ static int dw9719_power_up(struct > > > > dw9719_device *dw9719, bool detect) > > > >   if (ret) > > > >   return ret; > > > > - /* Jiggle SCL pin to wake up device */ > > > > - reg_pwr = (dw9719->model == DW9718S) ? DW9718S_PD : > > > > DW9719_CONTROL; > > > > - cci_write(dw9719->regmap, reg_pwr, DW9719_SHUTDOWN, &ret); > > > > - fsleep(100); > > > > + /* > > > > + * Need 100us to transition from SHUTDOWN to STANDBY. > > > > + * Jiggle the SCL pin to wake up the device (even when the > > > > regulator > > > > + * is shared) and wait double the time to be sure, then > > > > retry the write. > > > Why double? Isn't the datasheet correct when it comes to the power-on > > > sequence? > > > > > I haven't noticed any problems during power-up of DW9761. However, > > according to the commit message, there seems be an issue with DW9718S. > > But I don't own the device and cannot test it. > > > > Maybe Val can provided some additional information. > > I haven't had access to the datasheet for the DW9718S, so this was all > deduced experimentally. By "to be sure" I meant that I literally raised the > timeout "just in case", not based on actual issues. > > The actually important change was expecting the failure on the write and not > erroring out. Ack. André: could you add this information to the comment as well? -- Kind regards, Sakari Ailus