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 A5F4118CBE2; Wed, 31 Jul 2024 09:06:42 +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=1722416802; cv=none; b=TnAEhuvTlMV+drnUVnZV+CbIMAWN+S41H2tTMlA6m+AbAvNt5sQ4gydQjlRHd6Vjnx5KX2gO7uXXvYAuozUDVE5s8C0vuT+axZXCATOLRfVbrk1U9vfM2DsacYBPjmC+FQRutRrTbS2TyfCfIPSRhA1kaUBCM14RMxNrOU5j7YQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722416802; c=relaxed/simple; bh=ANu6zm1rnCnNMCrY5o/zlNBkWWaq05kV5ZeRvYWg8Qc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=BW1Sj70Xw21WcQEvXJVce5J8GhXcrid6umWFprLyPxAaPnZjZL1U20kw4bsVt2m6jsxW722evEdUmZ6hfSlKRoROajlUW9zMHj+lQZRM3vXW/RLpwhkEWOs52+VE58k1L8n/L+f9A3MzmKejSLsh5S9vPBh4O1xdCXVPXlSlTks= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=n0E+pVF6; 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="n0E+pVF6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4869DC116B1; Wed, 31 Jul 2024 09:06:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1722416802; bh=ANu6zm1rnCnNMCrY5o/zlNBkWWaq05kV5ZeRvYWg8Qc=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=n0E+pVF6iRFGAM/fFPULZeXkBJMlBb70WWTvzboJMetoTqCn89ICtmYeYHJKa+NaM st5hweJgfPgmvqH8GeQjmjK5/V4TWQWqfgTzwO3HCiDDd0NbSdIjyY6y+mAATky1Gv d70a0uOaLvQrJsspCTkWMrTI6dyo8kJTpDN71tbztZAcAZRXSCh49UQSS2Y0SjlXVE WwS2M9lkGZUpSFgYC7Yb5dAZli5G/bi9y5HFcTVaoiEgbMyEQA5w0gPaaNVMYnTpnd pddzUSb8S3LeoLEM/y78/xIxG8Z+nABOPubd5LZZUgzyMLfnlMHLcgT3ORjJJ368AY zomqVBcMhOM6Q== Message-ID: Date: Wed, 31 Jul 2024 11:06:38 +0200 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 2/2] media: imx335: Fix reset-gpio handling To: Kieran Bingham , Laurent Pinchart , Umang Jain Cc: Sakari Ailus , linux-media@vger.kernel.org, stable@vger.kernel.org, Tommaso Merciai , Jacopo Mondi References: <20240729110437.199428-1-umang.jain@ideasonboard.com> <20240729110437.199428-3-umang.jain@ideasonboard.com> <729280cd-557f-43ba-b1a6-8d319977ca82@kernel.org> <20240730091011.GL300@pendragon.ideasonboard.com> <172241654546.392292.16164306008596010671@ping.linuxembedded.co.uk> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 31/07/2024 11:02, Kieran Bingham wrote: > Quoting Umang Jain (2024-07-31 06:41:35) >> Hi all, >> >> On 30/07/24 2:40 pm, Laurent Pinchart wrote: >>> On Tue, Jul 30, 2024 at 10:42:01AM +0200, Krzysztof Kozlowski wrote: >>>> On 30/07/2024 10:24, Sakari Ailus wrote: >>>>> Hi Krzysztof, >>>>> >>>>> On Mon, Jul 29, 2024 at 04:09:39PM +0200, Krzysztof Kozlowski wrote: >>>>>> On 29/07/2024 13:04, Umang Jain wrote: >>>>>>> Rectify the logical value of reset-gpio so that it is set to >>>>>>> 0 (disabled) during power-on and to 1 (enabled) during power-off. >>>>>>> >>>>>>> Meanwhile at it, set the reset-gpio to GPIO_OUT_HIGH at initialization >>>>>>> time to make sure it starts off in reset. >>>>>>> >>>>>>> Fixes: 45d19b5fb9ae ("media: i2c: Add imx335 camera sensor driver") >>>>>>> Signed-off-by: Umang Jain >>>>>>> --- >>>>>>> drivers/media/i2c/imx335.c | 8 ++++---- >>>>>>> 1 file changed, 4 insertions(+), 4 deletions(-) >>>>>>> >>>>>> This will break all the users, so no. At least not without mentioning >>>>>> ABI break and some sort of investigating how customers or users are >>>>>> affected. >>>>> I know the original authors aren't using the driver anymore and it took >>>>> quite a bit of time until others started to contribute to it so I suspect >>>>> the driver hasn't been in use for that long. There are no instances of the >>>>> device in the in-kernel DTS either. >>>>> >>>>> Any DTS author should have also noticed the issue but of course there's a >>>>> risk someone could have just changed the polarity and not bothered to chech >>>>> what it was supposed to be. >>>>> >>>>> I agree the commit message should be more vocal about the effects on >>>>> existing DTS. >>>> I can imagine that all users (out of tree, in this case) inverted >>>> polarity in DTS based on what's implemented. You could go with some >>>> trivial hack, like I did for one of codecs - see 738455858a2d ("ASoC: >>>> codecs: wsa881x: Use proper shutdown GPIO polarity"), but I remember >>>> Mark Brown rejected similar commit for newer drivers. >>> I don't think there's any out-of-tree user, because when we started >>> using the recently driver, it required lots of fixes to even work at >>> all. I'll let Kieran and Umang comment on that, I haven't follow the >>> development in details. >> >> indeed, initially we had to put up fixes like : >> >> 14a60786d72e ("media: imx335: Set reserved register to default value") >> 81495a59baeba ("media: imx335: Fix active area height discrepency") >> >> to make the sensor work properly on our platforms. Only after that we >> had a base to support more capabilities on the sensor (multiple lanes >> support, flips, TPG etc.) > > I would also add that we had to provide control for the regulators to be > able to power the device as well in fea91ee73b7c ("media: i2c: imx335: > Enable regulator supplies"). Hm? That's not a proof of anything. Supplies are often turned on by default. > > Given the driver was posted from Intel, I would have anticipated perhaps > the driver was in fact only actually tested by Intel on ACPI platforms - > yet with no ACPI table registered in the driver - even that could likely > be considered broken. Nope, that does not work like that. Their platforms and such sensors are often used on DT based boards. Not mentioning even PRP0001. > > Based on that I have a high confidence that there are no current users > of this driver (except us). Nope, wrong conclusions, not that many arguments. Best regards, Krzysztof