e1000e: Remove mutex_trylock and associated WARN on failure.

Single-thread access must be ensured for ICH8 NVM and PHY operations.
This synchronization is provided by the nvm_mutex. To assist in
understanding the contexts from which this code could be reached,
a WARN was output if the mutex was not going to be immediately
acquirable (if !mutex_trylock()). The code has now been optimized,
and we have verified that the few remaining mutex contentions are
reasonable and non-blocking, and it is time to remove the
mutex_trylock() and WARN messages.

Signed-off-by: dave graham <david.graham@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/e1000e/ich8lan.c b/drivers/net/e1000e/ich8lan.c
index e415e81..6d1aab6 100644 (file)
--- a/drivers/net/e1000e/ich8lan.c
+++ b/drivers/net/e1000e/ich8lan.c
@@ -390,8 +390,6 @@ static s32 e1000_get_variants_ich8lan(struct e1000_adapter *adapter)
 }
 
 static DEFINE_MUTEX(nvm_mutex);
-static pid_t nvm_owner_pid = -1;
-static char nvm_owner_name[TASK_COMM_LEN] = "";
 
 /**
  *  e1000_acquire_swflag_ich8lan - Acquire software control flag
@@ -408,16 +406,7 @@ static s32 e1000_acquire_swflag_ich8lan(struct e1000_hw *hw)
 
        might_sleep();
 
-       if (!mutex_trylock(&nvm_mutex)) {
-               WARN(1, KERN_ERR "e1000e mutex contention. Owned by process "
-                    "%s (pid %d), required by process %s (pid %d)\n",
-                    nvm_owner_name, nvm_owner_pid,
-                    current->comm, current->pid);
-
-               mutex_lock(&nvm_mutex);
-       }
-       nvm_owner_pid = current->pid;
-       strncpy(nvm_owner_name, current->comm, TASK_COMM_LEN);
+       mutex_lock(&nvm_mutex);
 
        while (timeout) {
                extcnf_ctrl = er32(EXTCNF_CTRL);
@@ -435,8 +424,6 @@ static s32 e1000_acquire_swflag_ich8lan(struct e1000_hw *hw)
                hw_dbg(hw, "FW or HW has locked the resource for too long.\n");
                extcnf_ctrl &= ~E1000_EXTCNF_CTRL_SWFLAG;
                ew32(EXTCNF_CTRL, extcnf_ctrl);
-               nvm_owner_pid = -1;
-               strcpy(nvm_owner_name, "");
                mutex_unlock(&nvm_mutex);
                return -E1000_ERR_CONFIG;
        }
@@ -460,8 +447,6 @@ static void e1000_release_swflag_ich8lan(struct e1000_hw *hw)
        extcnf_ctrl &= ~E1000_EXTCNF_CTRL_SWFLAG;
        ew32(EXTCNF_CTRL, extcnf_ctrl);
 
-       nvm_owner_pid = -1;
-       strcpy(nvm_owner_name, "");
        mutex_unlock(&nvm_mutex);
 }