From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 505563A6B76; Mon, 3 Aug 2026 21:35:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785792928; cv=none; b=NoLuQDj+9cEOcfYFGB62jxOJN0CT1IP4vZJuIlhWY4ApzjTyRB2WrmFsc068UJbIRXZoujjXIOSslunMI0PvX+zVCeJ/a43IbgYEppXkPMlQDG3iNzt0yurHQ+KIqZqi2k7jZVBeEBsWvJtj/yufqVreRmf7EDzQeO4Ow2pPRDM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785792928; c=relaxed/simple; bh=3n8w35p/3OwGPmPUiQaFDESXD458de8OjR2qWTgwxHk=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=LMyy5D0TzwfdXzmMUCS/ZLy8LRTiYwAFC2PCCHQGcjnsU6eICbt4eIXXCdt+NJm1l6MsKZiWIva9Imgbwt/kJ/wgkGK9qU6V2Q0KmRM0hJLzp6VMpfsEg7ASadCaD5PCqL//qVAYvNbw1I7RKt879ETNyusDwtkuQyybAEvPDYc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jztQmdut; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jztQmdut" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C6E041F000E9; Mon, 3 Aug 2026 21:35:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785792926; bh=7f5O73n5KfjKRBZf5E7ytNS+WTEwuN1FZwpn3Z4J9DA=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=jztQmdutc+RuMSb06syMlHt82f50WUUIehYZQchj9bZnOvZt1hN1w90kQ1sVosMq5 6iU2PJrScfWQ5YQP6DFp2YQltrYiM6Afw/Eovc7Y7elipu9Z2bP9Jd7DBzfTqxlo51 p5hk2ObXHGxdTiXkH6EZK6LnIFvOjl1xgdqcxnqlttIlZG4oyLO/tNFa+Ub7H936dX K+Rf/3alOiEOwtJyaeuAErhz/Fzgn0ik5t6SZPtOkZLIJQU13qJx5gWtGgLuxltcea HN3E2sQSPa9CajQt/DGpdwWM3pbMB+BgBWMVXRXcO/gfr03+jPS+ZgbPQbXONUPqKR EPfPPWAUQinIw== Date: Mon, 3 Aug 2026 22:35:22 +0100 From: Jonathan Cameron To: Yuanshen Cao Cc: David Lechner , Nuno =?UTF-8?B?U8Oh?= , Andy Shevchenko , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] iio: light: tsl2772: fix ALS calibscale readback Message-ID: <20260803223522.7494bcc3@jic23-huawei> In-Reply-To: References: <20260724-tsl2772-calibscale-fix-v1-1-00a7789f4deb@gmail.com> <20260727031407.44a6d201@jic23-huawei> X-Mailer: Claws Mail 4.4.0 (GTK 3.24.52; x86_64-pc-linux-gnu) 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=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 27 Jul 2026 04:40:13 +0000 Yuanshen Cao wrote: > On Mon, Jul 27, 2026 at 03:14:07AM +0100, Jonathan Cameron wrote: > > On Fri, 24 Jul 2026 23:46:01 +0000 > > Yuanshen Cao wrote: > > > > > The read_raw() implementation uses IIO_LIGHT to distinguish between the > > > ambient light and proximity channels when handling > > > IIO_CHAN_INFO_CALIBSCALE. > > > > > > However, the ALS channel is registered as IIO_INTENSITY, while > > > write_raw() correctly writes to IIO_INTENSITY. As a result, reading > > > in_intensity0_calibscale incorrectly returns the proximity gain instead > > > of the ALS gain. > > > > > > This causes the following user-visible behavior: > > > - Writing in_intensity0_calibscale appears to have no effect because the > > > readback reports the proximity gain. > > > - Writing in_proximity0_calibscale causes both in_proximity0_calibscale > > > and in_intensity0_calibscale to report the same value. > > > > > > Fix this by checking for IIO_INTENSITY in read_raw(), matching the > > > channel definition and the existing write_raw() implementation. > > > > > > Signed-off-by: Yuanshen Cao > > Hi, > > > > Fix looks good and the explanation correct. Was this an AI found > > one, or did you either spot this whilst reading the code or best > > of all saw it in practice and went looking for what is wrong? > > Hi Jonathan, > > It's actually a bit of both. I first noticed the strange calibscale > behavior while testing a device with this sensor. Since most part of > this driver has been around for 7+ years, I wasn't expecting to find a > bug there. I asked ChatGPT for some ideas about what might explain the > behavior, and it pointed out the mismatch. I then went back and verified > it, and sure enough, it turned out to be a 14-year-old bug. After that, > I checked the rest of the file for similar issues, but this appears to > be the only instance. Also this was tested on the device and it works > as intended now. > > > Give it is fix, what is missing is a suitable Fixes tag. > > Please see if you can figure out what that should be. > > No need to send a v2 unless anything else comes up in review. > > Just reply to this thread with the Fixes tag so I'll get it > > when I use b4 to pick up the patch > > Thanks for pointing this out. > The missing tag is: > > Fixes: 3c97c08b5735 ("iio: light: add TAOS tsl2x7x driver") That's not the patch title. Unfortunately I missed running a check on this and it surfaced in linux-next forcing a rebase of the IIO tree to repair things. It's an ancient commit and the title didn't follow modern conventions staging: iio: add TAOS tsl2x7x driver Anyhow fixed up now Thanks, Jonathan > > Best, > > Yuanshen (Alex) Cao > > > Thanks, > > > > Jonathan > > > > > --- > > > drivers/iio/light/tsl2772.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/iio/light/tsl2772.c b/drivers/iio/light/tsl2772.c > > > index 244f44379c36..2287585711c6 100644 > > > --- a/drivers/iio/light/tsl2772.c > > > +++ b/drivers/iio/light/tsl2772.c > > > @@ -1274,7 +1274,7 @@ static int tsl2772_read_raw(struct iio_dev *indio_dev, > > > } > > > break; > > > case IIO_CHAN_INFO_CALIBSCALE: > > > - if (chan->type == IIO_LIGHT) > > > + if (chan->type == IIO_INTENSITY) > > > *val = tsl2772_als_gain[chip->settings.als_gain]; > > > else > > > *val = tsl2772_prox_gain[chip->settings.prox_gain]; > > > > > > --- > > > base-commit: 1590cf0329716306e948a8fc29f1d3ee87d3989f > > > change-id: 20260724-tsl2772-calibscale-fix-0cc42518d5fc > > > > > > Best regards, > > > -- > > > Yuanshen Cao > > > > > >