iwlwifi: always check if got h/w access before write
Before we write to the device registers always check if
iwl_grap_nic_access() was successful.
On the way change return type of grab_nic_access() to bool, and add
likely()/unlikely() statement.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-io.c b/drivers/net/wireless/iwlwifi/iwl-io.c
index fc36535..fa69845 100644
--- a/drivers/net/wireless/iwlwifi/iwl-io.c
+++ b/drivers/net/wireless/iwlwifi/iwl-io.c
@@ -118,16 +118,17 @@
return 0;
}
-int iwl_grab_nic_access(struct iwl_trans *trans)
+bool iwl_grab_nic_access(struct iwl_trans *trans)
{
int ret = iwl_grab_nic_access_silent(trans);
if (unlikely(ret)) {
u32 val = iwl_read32(trans, CSR_GP_CNTRL);
WARN_ONCE(1, "Timeout waiting for hardware access "
"(CSR_GP_CNTRL 0x%08x)\n", val);
+ return false;
}
- return ret;
+ return true;
}
void iwl_release_nic_access(struct iwl_trans *trans)
@@ -156,7 +157,7 @@
unsigned long flags;
spin_lock_irqsave(&trans->reg_lock, flags);
- if (!iwl_grab_nic_access(trans)) {
+ if (likely(iwl_grab_nic_access(trans))) {
iwl_write32(trans, reg, value);
iwl_release_nic_access(trans);
}
@@ -211,7 +212,7 @@
unsigned long flags;
spin_lock_irqsave(&trans->reg_lock, flags);
- if (!iwl_grab_nic_access(trans)) {
+ if (likely(iwl_grab_nic_access(trans))) {
__iwl_write_prph(trans, addr, val);
iwl_release_nic_access(trans);
}
@@ -223,9 +224,11 @@
unsigned long flags;
spin_lock_irqsave(&trans->reg_lock, flags);
- iwl_grab_nic_access(trans);
- __iwl_write_prph(trans, reg, __iwl_read_prph(trans, reg) | mask);
- iwl_release_nic_access(trans);
+ if (likely(iwl_grab_nic_access(trans))) {
+ __iwl_write_prph(trans, reg,
+ __iwl_read_prph(trans, reg) | mask);
+ iwl_release_nic_access(trans);
+ }
spin_unlock_irqrestore(&trans->reg_lock, flags);
}
@@ -235,10 +238,11 @@
unsigned long flags;
spin_lock_irqsave(&trans->reg_lock, flags);
- iwl_grab_nic_access(trans);
- __iwl_write_prph(trans, reg,
- (__iwl_read_prph(trans, reg) & mask) | bits);
- iwl_release_nic_access(trans);
+ if (likely(iwl_grab_nic_access(trans))) {
+ __iwl_write_prph(trans, reg,
+ (__iwl_read_prph(trans, reg) & mask) | bits);
+ iwl_release_nic_access(trans);
+ }
spin_unlock_irqrestore(&trans->reg_lock, flags);
}
@@ -248,10 +252,11 @@
u32 val;
spin_lock_irqsave(&trans->reg_lock, flags);
- iwl_grab_nic_access(trans);
- val = __iwl_read_prph(trans, reg);
- __iwl_write_prph(trans, reg, (val & ~mask));
- iwl_release_nic_access(trans);
+ if (likely(iwl_grab_nic_access(trans))) {
+ val = __iwl_read_prph(trans, reg);
+ __iwl_write_prph(trans, reg, (val & ~mask));
+ iwl_release_nic_access(trans);
+ }
spin_unlock_irqrestore(&trans->reg_lock, flags);
}
@@ -263,15 +268,13 @@
u32 *vals = buf;
spin_lock_irqsave(&trans->reg_lock, flags);
- iwl_grab_nic_access(trans);
-
- iwl_write32(trans, HBUS_TARG_MEM_RADDR, addr);
- rmb();
-
- for (offs = 0; offs < words; offs++)
- vals[offs] = iwl_read32(trans, HBUS_TARG_MEM_RDAT);
-
- iwl_release_nic_access(trans);
+ if (likely(iwl_grab_nic_access(trans))) {
+ iwl_write32(trans, HBUS_TARG_MEM_RADDR, addr);
+ rmb();
+ for (offs = 0; offs < words; offs++)
+ vals[offs] = iwl_read32(trans, HBUS_TARG_MEM_RDAT);
+ iwl_release_nic_access(trans);
+ }
spin_unlock_irqrestore(&trans->reg_lock, flags);
}
@@ -292,7 +295,7 @@
u32 *vals = buf;
spin_lock_irqsave(&trans->reg_lock, flags);
- if (!iwl_grab_nic_access(trans)) {
+ if (likely(iwl_grab_nic_access(trans))) {
iwl_write32(trans, HBUS_TARG_MEM_WADDR, addr);
wmb();