soc: qcom: pd-mapper: Fix element length in servreg_loc_pfr_req_ei

It looks element length declared in servreg_loc_pfr_req_ei for reason
not matching servreg_loc_pfr_req's reason field due which we could
observe decoding error on PD crash.

  qmi_decode_string_elem: String len 81 >= Max Len 65

Fix this by matching with servreg_loc_pfr_req's reason field.

Fixes: 1ebcde0 ("soc: qcom: add pd-mapper implementation")
Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Tested-by: Nikita Travkin <nikita@trvn.ru>
Link: https://lore.kernel.org/r/20260129152320.3658053-2-mukesh.ojha@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

Author: mukeshojha-linux

drivers/soc/qcom/pdr_internal.h

@@ -84,7 +84,7 @@ struct servreg_set_ack_resp {
 
 struct servreg_loc_pfr_req {
 	char service[SERVREG_NAME_LENGTH + 1];
-	char reason[257];
+	char reason[SERVREG_PFR_LENGTH + 1];
 };
 
 struct servreg_loc_pfr_resp {

drivers/soc/qcom/qcom_pdr_msg.c

@@ -325,7 +325,7 @@ const struct qmi_elem_info servreg_loc_pfr_req_ei[] = {
 	},
 	{
 		.data_type = QMI_STRING,
-		.elem_len = SERVREG_NAME_LENGTH + 1,
+		.elem_len = SERVREG_PFR_LENGTH + 1,
 		.elem_size = sizeof(char),
 		.array_type = VAR_LEN_ARRAY,
 		.tlv_type = 0x02,

include/linux/soc/qcom/pdr.h

@@ -5,6 +5,7 @@
 #include <linux/soc/qcom/qmi.h>
 
 #define SERVREG_NAME_LENGTH	64
+#define SERVREG_PFR_LENGTH	256
 
 struct pdr_service;
 struct pdr_handle;