[PATCH 2/6] hwmon: xgene: Stop writing PCC shared memory signature

[Sudeep Holla]

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@xxxxxxxxxxxx>
Cc: linux-hwmon@xxxxxxxxxxxxxxx
Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxxxxx>
---
 drivers/hwmon/xgene-hwmon.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/hwmon/xgene-hwmon.c b/drivers/hwmon/xgene-hwmon.c
index 11c5d80428cd..38b140c23c88 100644
--- a/drivers/hwmon/xgene-hwmon.c
+++ b/drivers/hwmon/xgene-hwmon.c
@@ -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));

-- 
2.43.0