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 C40BD1F4CB0; Tue, 4 Mar 2025 23:29:25 +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=1741130965; cv=none; b=mBd8YPqeLkMYnB8Z3+iWQRpCPubAHGmlM54+VvJMq/sSPus6MQDTeCK5ghB5y6oXUNDeUHqfJHJvVUXAuFrvdTvlSHIG5AgpgnBVG3WMEdB29TrEDLWxPa9amTXFiLymvpxtqzoLCOPL8kCNQ3a1fF0gmazmmrYYusK8CPV2IpU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741130965; c=relaxed/simple; bh=wRG2/3guVplG1fzSZhJr0O1MeFWo6h3depSrnEEaUuU=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=gi785SLykDpnbi7ak3wEWSPa/hVtEU6zWHIuisXRyZUu3V0BUhJr62KMltA+Q2GkRMfHgrt9mWq8JI8oLVWZvK/qgfhGpMYcXjK7uY7q8OVJ6+zAW/1g9ha9io2TiM4f7KbS+8VTIzwb7va1YzTJmog230eMhOc1HjfH0crzclI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EOrmORN2; 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="EOrmORN2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E96B2C4CEE5; Tue, 4 Mar 2025 23:29:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741130965; bh=wRG2/3guVplG1fzSZhJr0O1MeFWo6h3depSrnEEaUuU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=EOrmORN2cXFTtf4xgHiVYacgPtdIj2PQA1cmWGAFXVYhMfjY7YuzjdVqAsAsZSADp UGqFfkNr+DFxISDtg+Q+k5Az2dOBTpoIGL3GjJXWEiV5KG8JgfM3SSKtccM51wQnXU G6TKC4yEQm21V8tk+mdY+99FWnkCGpQJaobQwK+08f9F2CPkAOUfmzex5leU+eejHe 0QvA8ePd8Pl1REBqPOBtS0l+ZT62q6Fymi6acNTTr98B8OaqYB+YVKCYNNtTBD6ktP P2RskC78fqw78Qi+JWLmtEmuZrlc/Eha9leWs4hTj3sUl72Js/mfYFzixTWs+tJLUL Oyy5tLEa7kINw== Date: Tue, 4 Mar 2025 23:29:13 +0000 From: Jonathan Cameron To: Chris Morgan Cc: Chen-Yu Tsai , linux-pm@vger.kernel.org, linux-iio@vger.kernel.org, andre.przywara@arm.com, lee@kernel.org, sre@kernel.org, lars@metafoo.de, Chris Morgan Subject: Re: [PATCH 0/2] Fix Regression with AXP20X for 6.13-rc1 Message-ID: <20250304232913.020056fa@jic23-huawei> In-Reply-To: <67c743e3.050a0220.327e31.55b3@mx.google.com> References: <20241210224859.58917-1-macroalpha82@gmail.com> <20241211215826.06162190@jic23-huawei> <67606b09.050a0220.3905d.5bc7@mx.google.com> <67c743e3.050a0220.327e31.55b3@mx.google.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.48; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Tue, 4 Mar 2025 12:18:10 -0600 Chris Morgan wrote: > On Tue, Dec 17, 2024 at 02:04:37AM +0800, Chen-Yu Tsai wrote: > > On Tue, Dec 17, 2024 at 2:01=E2=80=AFAM Chris Morgan wrote: =20 > > > > > > On Wed, Dec 11, 2024 at 09:58:26PM +0000, Jonathan Cameron wrote: =20 > > > > On Tue, 10 Dec 2024 16:48:57 -0600 > > > > Chris Morgan wrote: > > > > =20 > > > > > From: Chris Morgan > > > > > > > > > > After performing a git bisect, I identified a commit that broke t= he > > > > > battery and charger driver for my AXP717 PMIC. This was caused by > > > > > commit e37ec3218870 ("mfd: axp20x: Allow multiple regulators"). > > > > > > > > > > After digging into it, it appears when mfd_add_devices was called= with > > > > > a platform ID of PLATFORM_DEVID_NONE, the devm_iio_channel_get() = call > > > > > made by the various AXP20X power drivers would not be able to gen= erate > > > > > a dev_name(dev) for some reason, and the iio_channel_get() call u= sed in > > > > > the devm_ helper would fall back to making a iio_channel_get_sys() > > > > > call. After the platform ID was updated, now iio_channel_get() is= no > > > > > longer falling back to iio_channel_get_sys(). At least this is my > > > > > limited understanding of what happened. =20 > > > > > > > > The dev_name(dev) not getting a name doesn't sound quite right to m= e. > > > > > > > > Time to look at the ancient creaking ghost that is the iio_map hand= ling. > > > > > > > > struct iio_channel *iio_channel_get(struct device *dev, > > > > const char *channel_name) > > > > { > > > > const char *name =3D dev ? dev_name(dev) : NULL; > > > > struct iio_channel *channel; > > > > > > > > if (dev) { > > > > channel =3D fwnode_iio_channel_get_by_name(dev_fwnode= (dev), > > > > channel_name= ); > > > > if (!IS_ERR(channel) || PTR_ERR(channel) !=3D -ENODEV) > > > > return channel; > > > > } > > > > > > > > return iio_channel_get_sys(name, channel_name); > > > > } > > > > EXPORT_SYMBOL_GPL(iio_channel_get); > > > > > > > > We didn't invent the relevant phandle stuff in DT via the patch you= point at > > > > so all that matters is what gets passed to that iio_channel_get_sys= () > > > > > > > > So key here is that dev should be set, so we are passing dev_name(d= ev) into > > > > iio_channel_get_sys() > > > > I'm guessing that changed... > > > > > > > > Ah. The iio_maps in > > > > https://elixir.bootlin.com/linux/v6.12.4/source/drivers/iio/adc/axp= 20x_adc.c#L158 > > > > are our problem. Those hardcode the consumer_dev name. The fix just= changed > > > > those names. Back when this infrastructure was written we were in t= he world of > > > > board files, so everything was hard coded in them - or in an MFD li= ke this > > > > it was treated as a singleton device. > > > > > > > > So as to how to fix it... Assuming the new device names are the sam= e for all > > > > the mfd parts that make up each pmic, then you should be able to fi= gure out the > > > > extra the number and build the channel maps to allow you to find t= he numbered > > > > devices. =20 > > > > > > Is there a way to figure out the device number at runtime? The issue = is > > > each time the device attempts to probe and fails, the device number > > > increments, making it a "hitting a moving target" problem. =20 > >=20 > > The ADC device is a mfd cell or child device of the PMIC mfd device. > > So you should be able to use dev->parent to get it directly? We do > > that at least for the regulator driver. =20 >=20 > Sorry to dig up such an old thread. I'm taking a look at this one again > and can confirm passing pdev->dev.parent to devm_iio_channel_get() is > insufficient to get the driver to find the correct ADC channel. Would > there be another/better way to do this other than the > devm_iio_channel_get_sys() as proposed? Or should we be walking the > parent somehow looking for the named ADC channel on each child device > (which would also require a new symbol most likely)? Hi Chris =46rom what I recall the point was to get the number from pdev->dev.parent rather than simply passing it to the devm_iio_channel_get() call. That should allow building of channel maps that provide the correct device name to allow the provider to be found. Jonathan >=20 > Thank you, > Chris >=20 > >=20 > > ChenYu > > =20 > > > Thank you, > > > Chris > > > =20 > > > > > > > > That's a lot lighter change than moving over to DT based phandles f= or all this. > > > > (which is the modern way to handle it). > > > > > > > > As a cheeky check, just edit those maps to whatever IDs you have an= d see > > > > if it works. Probably not an upstreamable solution but will confir= m we have > > > > it correct. > > > > > > > > Your patch works because we allow for some fuzzy matching (I can't = remember > > > > why) that doesn't use the consumer device name. > > > > That works as long as there is only one instance. I'm guessing all= this > > > > mess came about because someone has a board with two of these devic= es. On such > > > > a board we need the precise matching including the device name. > > > > > > > > Jonathan > > > > =20 > > > > > > > > > > To fix this, I added a new devm_ helper of devm_iio_channel_get_s= ys() > > > > > that directly calls iio_channel_get_sys(), and I updated all the > > > > > affected drivers with the new routine. I then no longer experienc= ed > > > > > any issues with the drivers on my devices. > > > > > > > > > > Chris Morgan (2): > > > > > iio: core: Add devm_ API for iio_channel_get_sys > > > > > power: supply: axp20x: Use devm_iio_channel_get_sys() for iio c= hans > > > > > > > > > > drivers/iio/inkern.c | 18 ++++++++++++++++++ > > > > > drivers/power/supply/axp20x_ac_power.c | 4 ++-- > > > > > drivers/power/supply/axp20x_battery.c | 16 ++++++++-------- > > > > > drivers/power/supply/axp20x_usb_power.c | 6 +++--- > > > > > include/linux/iio/consumer.h | 20 ++++++++++++++++++++ > > > > > 5 files changed, 51 insertions(+), 13 deletions(-) > > > > > =20 > > > > =20 >=20