Commit 6982a462 authored by Mallesh Koujalagi's avatar Mallesh Koujalagi Committed by Lucas De Marchi
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drm/xe/xe_late_bind_fw: Initialize uval variable in xe_late_bind_fw_num_fans() 



Initialize the uval variable to 0 in xe_late_bind_fw_num_fans() to fix
a potential use of uninitialized variable warning and ensure predictable
behavior.

The variable is passed by reference to xe_pcode_read() which should
populate it on success, but initializing it to 0 provides a safe
default value and follows kernel coding best practices.

v2:
- uval = 0 which serves as both a safe default and the fallback
  value when the pcode read operation fails.

v3:
- Handle MMIO failure (Rodrigo)
- The function should probably return the error and make the uval as
  pointer-argument, like the pcode_read.
- Change the caller of this function to propagate the error
  upwards if mmio failed.

Fixes: 45832bf9 ("drm/xe/xe_late_bind_fw: Initialize late binding firmware")
Signed-off-by: default avatarMallesh Koujalagi <mallesh.koujalagi@intel.com>
Link: https://lore.kernel.org/r/20251002005648.3185636-1-mallesh.koujalagi@intel.com


Reviewed-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
(cherry picked from commit 07abc16c)
Signed-off-by: default avatarLucas De Marchi <lucas.demarchi@intel.com>
parent 10aa5c80

drivers/gpu/drm/xe/xe_late_bind_fw.c

+8 −8
Original line number Diff line number Diff line
@@ -184,17 +184,13 @@ static const char *xe_late_bind_parse_status(uint32_t status) 
	}

}



static int xe_late_bind_fw_num_fans(struct xe_late_bind *late_bind)

static int xe_late_bind_fw_num_fans(struct xe_late_bind *late_bind, u32 *num_fans)

{

	struct xe_device *xe = late_bind_to_xe(late_bind);

	struct xe_tile *root_tile = xe_device_get_root_tile(xe);

	u32 uval;



	if (!xe_pcode_read(root_tile,

			   PCODE_MBOX(FAN_SPEED_CONTROL, FSC_READ_NUM_FANS, 0), &uval, NULL))

		return uval;

	else

		return 0;

	return xe_pcode_read(root_tile,

			     PCODE_MBOX(FAN_SPEED_CONTROL, FSC_READ_NUM_FANS, 0), num_fans, NULL);

}



void xe_late_bind_wait_for_worker_completion(struct xe_late_bind *late_bind)
@@ -314,7 +310,11 @@ static int __xe_late_bind_fw_init(struct xe_late_bind *late_bind, u32 fw_id) 
	lb_fw->flags &= ~INTEL_LB_FLAG_IS_PERSISTENT;



	if (lb_fw->type == INTEL_LB_TYPE_FAN_CONTROL) {

		num_fans = xe_late_bind_fw_num_fans(late_bind);

		ret = xe_late_bind_fw_num_fans(late_bind, &num_fans);

		if (ret) {

			drm_dbg(&xe->drm, "Failed to read number of fans: %d\n", ret);

			return 0; /* Not a fatal error, continue without fan control */

		}

		drm_dbg(&xe->drm, "Number of Fans: %d\n", num_fans);

		if (!num_fans)

			return 0;