[Mellanox] Fix retry logic on discovery of MST device (sonic-net#20389)

- Why I did it
Fixing retry logic when MST device is discovered. The current implementation only fetches the name of the device but doesn't verify if the device is accessible which can be confirmed by querying the device and ensuring the command passes.

- How I did it
Added a query command with device as parameter and ensured it passes.

- How to verify it
Running upgrade tests.

Author: dgsudharsan

files/scripts/syncd.sh

@@ -2,18 +2,6 @@
 
 . /usr/local/bin/syncd_common.sh
 
-declare -r UNKN_MST="unknown"
-
-function GetMstDevice() {
-    local _MST_DEVICE="$(ls /dev/mst/*_pci_cr0 2>&1)"
-
-    if [[ ! -c "${_MST_DEVICE}" ]]; then
-        echo "${UNKN_MST}"
-    else
-        echo "${_MST_DEVICE}"
-    fi
-}
-
 function startplatform() {
 
     # platform specific tasks
@@ -36,12 +24,7 @@ function startplatform() {
         debug "Starting Firmware update procedure"
         /usr/bin/mst start --with_i2cdev
 
-        local -r _MST_DEVICE="$(GetMstDevice)"
-        if [[ "${_MST_DEVICE}" != "${UNKN_MST}" ]]; then
-            /usr/bin/flint -d $_MST_DEVICE --clear_semaphore
-        fi
-
-        /usr/bin/mlnx-fw-upgrade.sh -v
+        /usr/bin/mlnx-fw-upgrade.sh -c -v
         if [[ "$?" -ne "${EXIT_SUCCESS}" ]]; then
             debug "Failed to upgrade fw. " "$?" "Restart syncd"
             exit 1

platform/mellanox/mlnx-fw-upgrade.j2

@@ -77,6 +77,7 @@ function PrintHelp() {
     echo "  -s, --syslog   Use syslog logger (enabled when -u|--upgrade)"
     echo "  -v, --verbose  Verbose mode (enabled when -u|--upgrade)"
     echo "  -d, --dry-run  Compare the FW versions without installation. Return code "0" means the FW is up-to-date, return code "10" means an upgrade is required, otherwise an error is detected."
+    echo "  -c, --clear-semaphore   Clear hw resources before updating firmware"
     echo "  -h, --help     Print help"
     echo
     echo "Examples:"
@@ -103,6 +104,9 @@ function ParseArguments() {
             -d|--dry-run)
                 DRY_RUN="${YES_PARAM}"
             ;;
+            -c|--clear-semaphore)
+                CLEAR_SEMAPHORE="${YES_PARAM}"
+            ;;
             -h|--help)
                 PrintHelp
                 exit "${EXIT_SUCCESS}"
@@ -210,16 +214,20 @@ function WaitForDevice() {
     local -i QUERY_RETRY_COUNT_MAX="10"
     local -i QUERY_RETRY_COUNT="0"
     local -r DEVICE_TYPE=$(GetMstDeviceType)
+    local SPC_MST_DEV
+    local QUERY_RC=""
 
-    local SPC_MST_DEV=$(GetSPCMstDevice)
-
-    while [[ ("${QUERY_RETRY_COUNT}" -lt "${QUERY_RETRY_COUNT_MAX}") && ("${SPC_MST_DEV}" == "${UNKN_MST}") ]]; do
+    while : ; do
+        SPC_MST_DEV=$(GetSPCMstDevice)
+        ${QUERY_XML} -d ${SPC_MST_DEV} -o ${QUERY_FILE}
+        QUERY_RC="$?"
+        [[ ("${QUERY_RETRY_COUNT}" -lt "${QUERY_RETRY_COUNT_MAX}") && ("${QUERY_RC}" != "${EXIT_SUCCESS}") ]] || break
         sleep 1s
         ((QUERY_RETRY_COUNT++))
-        SPC_MST_DEV=$(GetSPCMstDevice)
+        LogInfo "Retrying MST device query ${QUERY_RETRY_COUNT}"
     done
 
-    if [[ "${SPC_MST_DEV}" == "${UNKN_MST}" ]]; then
+    if [[ "${QUERY_RC}" != "${EXIT_SUCCESS}" ]]; then
         # Couldn't Detect the Spectrum ASIC. Exit failure and print the detailed information
         output=$(${QUERY_CMD})
         failure_msg="${output#*Fail : }"
@@ -265,7 +273,7 @@ function GetSPCMstDevice() {
 
     if [[ ! -c "${_MST_DEVICE}" ]]; then
         echo "${UNKN_MST}"
-    else 
+    else
         echo "${_MST_DEVICE}"
     fi
 
@@ -482,6 +490,15 @@ function Cleanup() {
     fi
 }
 
+function ClearSemaphore() {
+    if [[ "${CLEAR_SEMAPHORE}" == "${YES_PARAM}" ]]; then
+        local -r _MST_DEVICE="$(GetSPCMstDevice)"
+        if [[ "${_MST_DEVICE}" != "${UNKN_MST}" ]]; then
+            /usr/bin/flint -d $_MST_DEVICE --clear_semaphore
+        fi
+    fi
+}
+
 trap Cleanup EXIT
 
 ParseArguments "$@"
@@ -492,6 +509,8 @@ LockStateChange
 
 WaitForDevice
 
+ClearSemaphore
+
 if [ "${IMAGE_UPGRADE}" != "${YES_PARAM}" ]; then
     UpgradeFW
 else