lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <20241004125227.46514-1-brgl@bgdev.pl>
Date: Fri,  4 Oct 2024 14:52:27 +0200
From: Bartosz Golaszewski <brgl@...ev.pl>
To: Bartosz Golaszewski <brgl@...ev.pl>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Bjorn Andersson <andersson@...nel.org>,
	Konrad Dybcio <konradybcio@...nel.org>
Cc: linux-pci@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Bartosz Golaszewski <bartosz.golaszewski@...aro.org>,
	Johan Hovold <johan@...nel.org>,
	Stephan Gerhold <stephan.gerhold@...aro.org>
Subject: [PATCH] PCI/pwrctl: pwrseq: abandon probe on pre-pwrseq device-trees

From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>

Old device trees for some platforms already define wifi nodes for the WCN
family of chips since before power sequencing was added upstream.

These nodes don't consume the regulator outputs from the PMU and if we
allow this driver to bind to one of such "incomplete" nodes, we'll see
a kernel log error about the indefinite probe deferral.

Let's check the existence of the regulator supply that exists on all WCN
models before moving forward.

Fixes: 6140d185a43d ("PCI/pwrctl: Add a PCI power control driver for power sequenced devices")
Reported-by: Johan Hovold <johan@...nel.org>
Closes: https://lore.kernel.org/all/Zv565olMDDGHyYVt@hovoldconsulting.com/
Suggested-by: Stephan Gerhold <stephan.gerhold@...aro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
---
 drivers/pci/pwrctl/pci-pwrctl-pwrseq.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c b/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c
index a23a4312574b..8ed613655d4a 100644
--- a/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c
+++ b/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c
@@ -9,6 +9,7 @@
 #include <linux/of.h>
 #include <linux/pci-pwrctl.h>
 #include <linux/platform_device.h>
+#include <linux/property.h>
 #include <linux/pwrseq/consumer.h>
 #include <linux/slab.h>
 #include <linux/types.h>
@@ -31,6 +32,25 @@ static int pci_pwrctl_pwrseq_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	int ret;
 
+	/*
+	 * Old device trees for some platforms already define wifi nodes for
+	 * the WCN family of chips since before power sequencing was added
+	 * upstream.
+	 *
+	 * These nodes don't consume the regulator outputs from the PMU and
+	 * if we allow this driver to bind to one of such "incomplete" nodes,
+	 * we'll see a kernel log error about the indefinite probe deferral.
+	 *
+	 * Let's check the existence of the regulator supply that exists on all
+	 * WCN models before moving forward.
+	 *
+	 * NOTE: If this driver is ever used to support a device other than
+	 * a WCN chip, the following lines should become conditional and depend
+	 * on the compatible string.
+	 */
+	if (!device_property_present(dev, "vddaon-supply"))
+		return -ENODEV;
+
 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
-- 
2.43.0


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ