[PATCH v4 4/9] firmware: arm_scmi: Fall back to ACPI HID when "compatible" is absent
From: Sudeep Holla <sudeep.holla@kernel.org>
Date: 2026-09-04 15:59:43
Also in:
arm-scmi
Subsystem:
system control & power/management interface (scpi/scmi) message protocol drivers, the rest · Maintainers:
Sudeep Holla, Linus Torvalds
scmi_debugfs_common_setup() uses the "compatible" property to populate the debugfs transport type string. ACPI-described SCMI devices do not provide that DT property, so the string remains NULL and debugfs setup falls through the allocation failure path. Check the property lookup result and use the ACPI HID as the fallback transport type when an ACPI companion is present. All supported DT SCMI platforms are expected to provide "compatible", so the non-ACPI fallback is not needed for normal DT operation. Keep the explicit "unknown" fallback anyway to avoid passing NULL to kstrdup() if that assumption is ever violated. Signed-off-by: Sudeep Holla <sudeep.holla@kernel.org> --- drivers/firmware/arm_scmi/driver.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 7e239f52c888..51829550636f 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c@@ -16,6 +16,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/acpi.h> #include <linux/bitmap.h> #include <linux/cleanup.h> #include <linux/debugfs.h>
@@ -3063,6 +3064,15 @@ static void scmi_debugfs_common_cleanup(void *d) kfree(dbg->type); } +static const char *scmi_acpi_device_hid(struct acpi_device *adev) +{ +#ifdef CONFIG_ACPI + return adev ? acpi_device_hid(adev) : "unknown"; +#else + return "unknown"; +#endif +} + static struct scmi_debug_info *scmi_debugfs_common_setup(struct scmi_info *info) { char top_dir[16];
@@ -3080,8 +3090,10 @@ static struct scmi_debug_info *scmi_debugfs_common_setup(struct scmi_info *info) return NULL; } - fwnode_property_read_string(dev_fwnode(info->dev), "compatible", - &c_ptr); + if (fwnode_property_read_string(dev_fwnode(info->dev), "compatible", + &c_ptr)) + c_ptr = scmi_acpi_device_hid(ACPI_COMPANION(info->dev)); + dbg->type = kstrdup(c_ptr, GFP_KERNEL); if (!dbg->type) { kfree(dbg->name);
--
2.43.0