linux-kernel - Re: [PATCH v4 00/10] gpio: improve support for shared GPIOs

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Message-ID: <CAMRc=McHCG8N0zeVUUvYF+rHqBrBKe52o+pf+Hjp5dnG3+NmjA@mail.gmail.com>
Date: Fri, 21 Nov 2025 10:03:40 +0100
From: Bartosz Golaszewski <brgl@...ev.pl>
To: Val Packett <val@...kett.cool>
Cc: Kees Cook <kees@...nel.org>, Mika Westerberg <westeri@...nel.org>, 
	Dmitry Torokhov <dmitry.torokhov@...il.com>, Andrew Morton <akpm@...ux-foundation.org>, 
	Linus Walleij <linus.walleij@...aro.org>, Manivannan Sadhasivam <mani@...nel.org>, 
	Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>, 
	Saravana Kannan <saravanak@...gle.com>, Greg Kroah-Hartman <gregkh@...uxfoundation.org>, 
	Andy Shevchenko <andy@...nel.org>, Catalin Marinas <catalin.marinas@....com>, Will Deacon <will@...nel.org>, 
	Srinivas Kandagatla <srini@...nel.org>, Liam Girdwood <lgirdwood@...il.com>, Mark Brown <broonie@...nel.org>, 
	Jaroslav Kysela <perex@...ex.cz>, Takashi Iwai <tiwai@...e.com>, 
	Alexey Klimov <alexey.klimov@...aro.org>, Bjorn Andersson <andersson@...nel.org>, 
	Konrad Dybcio <konradybcio@...nel.org>, linux-hardening@...r.kernel.org, 
	linux-kernel@...r.kernel.org, linux-gpio@...r.kernel.org, 
	linux-arm-kernel@...ts.infradead.org, linux-sound@...r.kernel.org, 
	linux-arm-msm@...r.kernel.org, 
	Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Subject: Re: [PATCH v4 00/10] gpio: improve support for shared GPIOs

On Fri, Nov 21, 2025 at 1:28 AM Val Packett <val@...kett.cool> wrote:
>
> Hi,
>
> On 11/12/25 10:55 AM, Bartosz Golaszewski wrote:
> > ---
> > Bartosz Golaszewski (10):
> >        string: provide strends()
> >        gpiolib: define GPIOD_FLAG_SHARED
> >        gpiolib: implement low-level, shared GPIO support
> >        gpio: shared-proxy: implement the shared GPIO proxy driver
> >        gpiolib: support shared GPIOs in core subsystem code
> >        gpio: provide gpiod_is_shared()
> >        arm64: select HAVE_SHARED_GPIOS for ARCH_QCOM
> >        ASoC: wsa881x: drop GPIOD_FLAGS_BIT_NONEXCLUSIVE flag from GPIO lookup
> >        ASoC: wsa883x: drop GPIOD_FLAGS_BIT_NONEXCLUSIVE flag from GPIO lookup
> >        regulator: make the subsystem aware of shared GPIOs
>
> this seems to actually have caused a regression for me, audio does not
> initialize anymore on hamoa due to EBUSY since upgrading
> from next-20251114 to next-20251118 or next-20251120:
>

Thanks for the heads-up.

> [   11.748781] platform
> 6800000.remoteproc:glink-edge:gpr:service@1:dais: Adding to iommu group 30
> [   11.785864] wsa_macro 6aa0000.codec: using zero-initialized flat
> cache, this may cause unexpected behavior
> [   11.796964] reset-gpio reset-gpio.0: error -EBUSY: Could not get
> reset gpios
> [   11.796984] reset-gpio reset-gpio.0: probe with driver reset-gpio
> failed with error -16
> [   11.894662] reset-gpio reset-gpio.1: error -EBUSY: Could not get
> reset gpios
> [   11.894676] reset-gpio reset-gpio.1: probe with driver reset-gpio
> failed with error -16

It seems like it's the reset-gpio driver, not shared GPIOLIB path?
This driver has never used the GPIOD_FLAGS_BIT_NONEXCLUSIVE flag.

> [   12.006938] wcd938x_codec audio-codec: bound sdw:2:0:0217:010d:00:4
> (ops wcd_sdw_component_ops [snd_soc_wcd_common])
> [   12.006964] wcd938x_codec audio-codec: bound sdw:3:0:0217:010d:00:3
> (ops wcd_sdw_component_ops [snd_soc_wcd_common])
> [   15.424657] qcom-soundwire 6ab0000.soundwire: qcom_swrm_irq_handler:
> SWR CMD error, fifo status 0x4e00c00f, flushing fifo
> [   21.994354] qcom-soundwire 6ab0000.soundwire: qcom_swrm_irq_handler:
> SWR CMD error, fifo status 0xe00c000, flushing fifo
> [   21.996001] qcom-soundwire 6b10000.soundwire: qcom_swrm_irq_handler:
> SWR CMD error, fifo status 0x4e00c00f, flushing fifo
> [   21.996239] platform sound: deferred probe pending: snd-x1e80100: WSA
> Playback: codec dai not found
> [   21.996248] soundwire sdw:4:0:0217:0204:00:0: deferred probe pending:
> wsa884x-codec: Failed to get reset
> [   21.996250] soundwire sdw:4:0:0217:0204:00:1: deferred probe pending:
> wsa884x-codec: Failed to get reset
> [   21.996251] soundwire sdw:1:0:0217:0204:00:0: deferred probe pending:
> wsa884x-codec: Failed to get reset
> [   21.996253] soundwire sdw:1:0:0217:0204:00:1: deferred probe pending:
> wsa884x-codec: Failed to get reset
>
> gpio_shared_proxy, reset_gpio, pinctrl_sm8550_lpass_lpi are all built as
> modules and were autoloaded fine.
>
> This is wsa884x (not wsa881x nor wsa883x), failing in
> devm_reset_control_get_optional_shared..
>

Can you enable DEBUG_GPIO in menuconfig and post the entire kernel log
somewhere as well as the output of gpiodetect and gpioinfo after
booting?

Bartosz