ixgbe: clear semaphore bits on timeouts

This patch changes the error code path in ixgbe_acquire_swfw_sync() to deal
with cases where acquiring SW semaphore times out.

In cases where the SW/FW semaphore bits were set (i.e. due to a crash) the
driver will hang on load. With this patch the driver will clear
the stuck bits if the semaphore was not acquired in the allotted time.

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
index 0d09711..50e62a2 100644 (file)
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
@@ -2506,42 +2506,39 @@ out:
  **/
 s32 ixgbe_acquire_swfw_sync(struct ixgbe_hw *hw, u16 mask)
 {
-       u32 gssr;
+       u32 gssr = 0;
        u32 swmask = mask;
        u32 fwmask = mask << 5;
-       s32 timeout = 200;
+       u32 timeout = 200;
+       u32 i;
 
-       while (timeout) {
+       for (i = 0; i < timeout; i++) {
                /*
-                * SW EEPROM semaphore bit is used for access to all
-                * SW_FW_SYNC/GSSR bits (not just EEPROM)
+                * SW NVM semaphore bit is used for access to all
+                * SW_FW_SYNC bits (not just NVM)
                 */
                if (ixgbe_get_eeprom_semaphore(hw))
                        return IXGBE_ERR_SWFW_SYNC;
 
                gssr = IXGBE_READ_REG(hw, IXGBE_GSSR);
-               if (!(gssr & (fwmask | swmask)))
-                       break;
-
-               /*
-                * Firmware currently using resource (fwmask) or other software
-                * thread currently using resource (swmask)
-                */
-               ixgbe_release_eeprom_semaphore(hw);
-               usleep_range(5000, 10000);
-               timeout--;
-       }
-
-       if (!timeout) {
-               hw_dbg(hw, "Driver can't access resource, SW_FW_SYNC timeout.\n");
-               return IXGBE_ERR_SWFW_SYNC;
+               if (!(gssr & (fwmask | swmask))) {
+                       gssr |= swmask;
+                       IXGBE_WRITE_REG(hw, IXGBE_GSSR, gssr);
+                       ixgbe_release_eeprom_semaphore(hw);
+                       return 0;
+               } else {
+                       /* Resource is currently in use by FW or SW */
+                       ixgbe_release_eeprom_semaphore(hw);
+                       usleep_range(5000, 10000);
+               }
        }
 
-       gssr |= swmask;
-       IXGBE_WRITE_REG(hw, IXGBE_GSSR, gssr);
+       /* If time expired clear the bits holding the lock and retry */
+       if (gssr & (fwmask | swmask))
+               ixgbe_release_swfw_sync(hw, gssr & (fwmask | swmask));
 
-       ixgbe_release_eeprom_semaphore(hw);
-       return 0;
+       usleep_range(5000, 10000);
+       return IXGBE_ERR_SWFW_SYNC;
 }
 
 /**