From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Linux ACPI <linux-acpi@vger.kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Salil Mehta <salil.mehta@huawei.com>,
Jonathan Cameron <jonathan.cameron@huawei.com>
Subject: [PATCH v1] ACPI: scan: Avoid enumerating devices with clearly invalid _STA values
Date: Fri, 26 Apr 2024 18:56:21 +0200 [thread overview]
Message-ID: <2741433.mvXUDI8C0e@kreacher> (raw)
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The return value of _STA with the "present" bit unset and the "enabled"
bit set is clearly invalid as per the ACPI specification, Section 6.3.7
"_STA (Device Status)", so make the ACPI device enumeration code
disregard devices with such _STA return values.
Also, because this implies that status.enabled will only be set if
status.present is set too, acpi_device_is_enabled() can be modified
to simply return the value of the former.
Link: https://uefi.org/specs/ACPI/6.5/06_Device_Configuration.html#sta-device-status
Link: https://lore.kernel.org/linux-acpi/88179311a503493099028c12ca37d430@huawei.com/
Suggested-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/acpi/bus.c | 11 +++++++++++
drivers/acpi/scan.c | 2 +-
2 files changed, 12 insertions(+), 1 deletion(-)
Index: linux-pm/drivers/acpi/bus.c
===================================================================
--- linux-pm.orig/drivers/acpi/bus.c
+++ linux-pm/drivers/acpi/bus.c
@@ -112,6 +112,17 @@ int acpi_bus_get_status(struct acpi_devi
if (ACPI_FAILURE(status))
return -ENODEV;
+ if (!device->status.present && device->status.enabled) {
+ pr_info(FW_BUG "Device [%s] status [%08x]: not present and enabled\n",
+ device->pnp.bus_id, (u32)sta);
+ device->status.enabled = 0;
+ /*
+ * The status is clearly invalid, so clear the enabled bit as
+ * well to avoid attempting to use the device.
+ */
+ device->status.functional = 0;
+ }
+
acpi_set_device_status(device, sta);
if (device->status.functional && !device->status.present) {
Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -1962,7 +1962,7 @@ bool acpi_device_is_present(const struct
bool acpi_device_is_enabled(const struct acpi_device *adev)
{
- return adev->status.present && adev->status.enabled;
+ return adev->status.enabled;
}
static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
next reply other threads:[~2024-04-26 16:56 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-26 16:56 Rafael J. Wysocki [this message]
2024-04-28 4:17 ` [PATCH v1] ACPI: scan: Avoid enumerating devices with clearly invalid _STA values Zhang, Rui
2024-04-29 16:06 ` Rafael J. Wysocki
2024-04-29 8:29 ` Jonathan Cameron
2024-04-29 16:07 ` Rafael J. Wysocki
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