[PATCH 1/2] phy: qcom: qmp-pcie: Select MFD_SYSCON for the multi-PHY driver

[PATCH 1/2] phy: qcom: qmp-pcie: Select MFD_SYSCON for the multi-PHY driver

[David Carlier]

The driver reads the active link mode through
syscon_regmap_lookup_by_phandle_args(). Without CONFIG_MFD_SYSCON the
stub returning -ENOTSUPP is compiled in instead, so probe fails for
every device and no PHY is ever registered.

Nothing in the build catches this: the driver still compiles, and arm64
defconfig happens to enable MFD_SYSCON through an unrelated select.

Fixes: 1781be3c8a5d ("phy: qcom: qmp-pcie: Add QMP PCIe Multi-PHY driver")
Signed-off-by: David Carlier <devnexen@gmail.com>
---
 drivers/phy/qualcomm/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/phy/qualcomm/Kconfig b/drivers/phy/qualcomm/Kconfig
index d910a5d1a1ac..9113e1099245 100644
--- a/drivers/phy/qualcomm/Kconfig
+++ b/drivers/phy/qualcomm/Kconfig
@@ -81,6 +81,7 @@ config PHY_QCOM_QMP_PCIE_MULTIPHY
 	tristate "Qualcomm QMP PCIe Multi PHY Driver"
 	depends on PCI || COMPILE_TEST
 	select GENERIC_PHY
+	select MFD_SYSCON
 	help
 	  Enable this to support the QMP PCIe PHY transceiver that is used
 	  with PCIe controllers on Qualcomm chips. This PHY is a single
-- 
2.55.0


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[PATCH 2/2] phy: qcom: qmp-pcie: Check clock-output-names count in the multi-PHY driver

[David Carlier]

of_property_count_strings() returns a negative errno when the property
is missing or malformed. The value was passed straight to
devm_kcalloc(), whose overflow check rejected it, turning a device tree
problem into a bogus -ENOMEM with no diagnostic.

Fixes: 1781be3c8a5d ("phy: qcom: qmp-pcie: Add QMP PCIe Multi-PHY driver")
Signed-off-by: David Carlier <devnexen@gmail.com>
---
 drivers/phy/qualcomm/phy-qcom-qmp-pcie-multiphy.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie-multiphy.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie-multiphy.c
index e93cba4369fb..e747ff9c3e5d 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie-multiphy.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie-multiphy.c
@@ -555,6 +555,9 @@ static int qmp_pcie_multiphy_register_clocks(struct device *dev,
 	int i, ret;
 
 	num_pipe_outputs = of_property_count_strings(np, "clock-output-names");
+	if (num_pipe_outputs < 0)
+		return dev_err_probe(dev, num_pipe_outputs,
+				     "failed to read clock-output-names\n");
 
 	qmp_data->num_pipe_outputs = num_pipe_outputs;
 	qmp_data->pipe_out_clks = devm_kcalloc(dev, num_pipe_outputs,
-- 
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Re: [PATCH 2/2] phy: qcom: qmp-pcie: Check clock-output-names count in the multi-PHY driver

[Konrad Dybcio]

On 8/26/26 12:57 AM, David Carlier wrote:
> of_property_count_strings() returns a negative errno when the property
> is missing or malformed. The value was passed straight to
> devm_kcalloc(), whose overflow check rejected it, turning a device tree
> problem into a bogus -ENOMEM with no diagnostic.
> 
> Fixes: 1781be3c8a5d ("phy: qcom: qmp-pcie: Add QMP PCIe Multi-PHY driver")
> Signed-off-by: David Carlier <devnexen@gmail.com>
> ---

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

Konrad

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Re: [PATCH 1/2] phy: qcom: qmp-pcie: Select MFD_SYSCON for the multi-PHY driver

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:

New issues:
- [Low] Unmet direct dependency warning caused by unconditionally selecting MFD_SYSCON in a driver supporting COMPILE_TEST without inheriting its HAS_IOMEM dependency.

Pre-existing issues:
- [High] Incomplete fix: The regular QMP PCIe driver (PHY_QCOM_QMP_PCIE) also unconditionally calls syscon_regmap_lookup_by_phandle_args() but still lacks a select for MFD_SYSCON, leaving it vulnerable to the exact same probe failure.
--

commit ca7057ced5dd6d2650998c03785e590bdadcd6f2
Author: David Carlier <devnexen@gmail.com>

phy: qcom: qmp-pcie: Select MFD_SYSCON for the multi-PHY driver

The driver reads the active link mode through
syscon_regmap_lookup_by_phandle_args(). Without CONFIG_MFD_SYSCON, the stub
returns -ENOTSUPP, causing probe failures. This patch adds the missing
MFD_SYSCON selection to the PHY_QCOM_QMP_PCIE_MULTIPHY driver.

> diff --git a/drivers/phy/qualcomm/Kconfig b/drivers/phy/qualcomm/Kconfig
> index d910a5d1a1ac3..9113e10992457 100644
> --- a/drivers/phy/qualcomm/Kconfig
> +++ b/drivers/phy/qualcomm/Kconfig
> @@ -81,6 +81,7 @@ config PHY_QCOM_QMP_PCIE_MULTIPHY
>  	tristate "Qualcomm QMP PCIe Multi PHY Driver"
>  	depends on PCI || COMPILE_TEST
>  	select GENERIC_PHY
> +	select MFD_SYSCON

[Severity: Low]
Does this unconditionally select MFD_SYSCON without inheriting its hardware
dependencies?

When configuring the kernel with COMPILE_TEST enabled on an architecture
lacking HAS_IOMEM (such as s390 without PCI or UML without IOMEM), this can
trigger Kconfig warnings for unmet direct dependencies and potential build
failures.

[Severity: High]
This is a pre-existing issue, but does the regular PHY_QCOM_QMP_PCIE driver
have the exact same probe failure vulnerability?

In drivers/phy/qualcomm/Kconfig, config PHY_QCOM_QMP_PCIE lacks a select for
MFD_SYSCON:

config PHY_QCOM_QMP_PCIE
	tristate "Qualcomm QMP PCIe PHY Driver"
	depends on PCI || COMPILE_TEST
	select GENERIC_PHY

This driver unconditionally calls syscon_regmap_lookup_by_phandle_args() in
drivers/phy/qualcomm/phy-qcom-qmp-pcie.c:qmp_pcie_get_4ln_config():

	tcsr = syscon_regmap_lookup_by_phandle_args(qmp->dev->of_node,
						    "qcom,4ln-config-sel",
						    ARRAY_SIZE(args), args);
	if (IS_ERR(tcsr)) {
		ret = PTR_ERR(tcsr);
		if (ret == -ENOENT)
			return 0;

		dev_err(qmp->dev, "failed to lookup syscon: %d\n", ret);
		return ret;
	}

If MFD_SYSCON is disabled, the stub returns -ENOTSUPP. Since this explicitly
checks for -ENOENT but not -ENOTSUPP, wouldn't the probe fail unconditionally
and leave the PCIe bus non-functional?

>  	help
>  	  Enable this to support the QMP PCIe PHY transceiver that is used
> [ ... ]

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Re: [PATCH 1/2] phy: qcom: qmp-pcie: Select MFD_SYSCON for the multi-PHY driver

[Konrad Dybcio]

On 8/26/26 12:57 AM, David Carlier wrote:
> The driver reads the active link mode through
> syscon_regmap_lookup_by_phandle_args(). Without CONFIG_MFD_SYSCON the
> stub returning -ENOTSUPP is compiled in instead, so probe fails for
> every device and no PHY is ever registered.
> 
> Nothing in the build catches this: the driver still compiles, and arm64
> defconfig happens to enable MFD_SYSCON through an unrelated select.
> 
> Fixes: 1781be3c8a5d ("phy: qcom: qmp-pcie: Add QMP PCIe Multi-PHY driver")
> Signed-off-by: David Carlier <devnexen@gmail.com>
> ---

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

Konrad

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