hwmon: xgene: Stop writing PCC shared memory signature

ACPI specification defines the generic PCC shared memory signature as
the PCC base signature ORed with the subspace ID.

ACPI 6.6 added clarification that the signature is populated by the
platform and verified by OSPM.

The PCC mailbox controller now validates the signature when the channel
is requested. Stop rewriting the signature before each command and
leave the platform-populated value intact.

Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-hwmon@vger.kernel.org
Signed-off-by: Sudeep Holla <sudeep.holla@kernel.org>
Link: https://lore.kernel.org/r/20260627-acpi_pcc_signature-v1-2-c1b7268d4fdc@kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Sudeep Holla
2026-07-27 20:30:43 -07:00
committed by Guenter Roeck
parent e573fd3dc3
commit 7234b39701
-4
View File
@@ -133,10 +133,6 @@ static int xgene_hwmon_pcc_rd(struct xgene_hwmon_dev *ctx, u32 *msg)
init_completion(&ctx->rd_complete);
ctx->resp_pending = true;
/* Write signature for subspace */
WRITE_ONCE(generic_comm_base->signature,
cpu_to_le32(PCC_SIGNATURE | ctx->mbox_idx));
/* Write to the shared command region */
WRITE_ONCE(generic_comm_base->command,
cpu_to_le16(MSG_TYPE(msg[0]) | PCC_CMD_GENERATE_DB_INTR));