[PATCH] bcm43xx: voluntary preemtion in the calibration loops

This patch adds voluntary preemption points into the
PHY calibration loops to allow non-CONFIG_PREEMPT machines
to not suffer from huge delays.
CONFIG_PREEMPT machines are already fine, because all this
code is run in non-atomic process context.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 18 insertions, 15 deletions

diff --git a/drivers/net/wireless/bcm43xx/bcm43xx_phy.c b/drivers/net/wireless/bcm43xx/bcm43xx_phy.c
index f8200deecc8a..eafd0f662686 100644
--- a/drivers/net/wireless/bcm43xx/bcm43xx_phy.c
+++ b/drivers/net/wireless/bcm43xx/bcm43xx_phy.c
@@ -81,6 +81,16 @@ static const s8 bcm43xx_tssi2dbm_g_table[] = {
 static void bcm43xx_phy_initg(struct bcm43xx_private *bcm);
 
 
+static inline
+void bcm43xx_voluntary_preempt(void)
+{
+        assert(!in_atomic() && !in_irq() &&
+               !in_interrupt() && !irqs_disabled());
+#ifndef CONFIG_PREEMPT
+        cond_resched();
+#endif /* CONFIG_PREEMPT */
+}
+
 void bcm43xx_raw_phy_lock(struct bcm43xx_private *bcm)
 {
         struct bcm43xx_phyinfo *phy = bcm43xx_current_phy(bcm);
@@ -133,22 +143,14 @@ void bcm43xx_phy_write(struct bcm43xx_private *bcm, u16 offset, u16 val)
 void bcm43xx_phy_calibrate(struct bcm43xx_private *bcm)
 {
         struct bcm43xx_phyinfo *phy = bcm43xx_current_phy(bcm);
-        unsigned long flags;
 
         bcm43xx_read32(bcm, BCM43xx_MMIO_STATUS_BITFIELD); /* Dummy read. */
         if (phy->calibrated)
                 return;
         if (phy->type == BCM43xx_PHYTYPE_G && phy->rev == 1) {
-                /* We do not want to be preempted while calibrating
-                 * the hardware.
-                 */
-                local_irq_save(flags);
-
                 bcm43xx_wireless_core_reset(bcm, 0);
                 bcm43xx_phy_initg(bcm);
                 bcm43xx_wireless_core_reset(bcm, 1);
-
-                local_irq_restore(flags);
         }
         phy->calibrated = 1;
 }
@@ -1299,7 +1301,9 @@ static u16 bcm43xx_phy_lo_b_r15_loop(struct bcm43xx_private *bcm)
 {
         int i;
         u16 ret = 0;
+        unsigned long flags;
 
+        local_irq_save(flags);
         for (i = 0; i < 10; i++){
                 bcm43xx_phy_write(bcm, 0x0015, 0xAFA0);
                 udelay(1);
@@ -1309,6 +1313,8 @@ static u16 bcm43xx_phy_lo_b_r15_loop(struct bcm43xx_private *bcm)
                 udelay(40);
                 ret += bcm43xx_phy_read(bcm, 0x002C);
         }
+        local_irq_restore(flags);
+        bcm43xx_voluntary_preempt();
 
         return ret;
 }
@@ -1435,6 +1441,7 @@ u16 bcm43xx_phy_lo_g_deviation_subval(struct bcm43xx_private *bcm, u16 control)
         }
         ret = bcm43xx_phy_read(bcm, 0x002D);
         local_irq_restore(flags);
+        bcm43xx_voluntary_preempt();
 
         return ret;
 }
@@ -1760,6 +1767,7 @@ void bcm43xx_phy_lo_g_measure(struct bcm43xx_private *bcm)
                         bcm43xx_radio_write16(bcm, 0x43, i);
                         bcm43xx_radio_write16(bcm, 0x52, radio->txctl2);
                         udelay(10);
+                        bcm43xx_voluntary_preempt();
 
                         bcm43xx_phy_set_baseband_attenuation(bcm, j * 2);
 
@@ -1803,6 +1811,7 @@ void bcm43xx_phy_lo_g_measure(struct bcm43xx_private *bcm)
                                               radio->txctl2
                                               | (3/*txctl1*/ << 4));//FIXME: shouldn't txctl1 be zero here and 3 in the loop above?
                         udelay(10);
+                        bcm43xx_voluntary_preempt();
 
                         bcm43xx_phy_set_baseband_attenuation(bcm, j * 2);
 
@@ -1824,6 +1833,7 @@ void bcm43xx_phy_lo_g_measure(struct bcm43xx_private *bcm)
                 bcm43xx_phy_write(bcm, 0x0812, (r27 << 8) | 0xA2);
                 udelay(2);
                 bcm43xx_phy_write(bcm, 0x0812, (r27 << 8) | 0xA3);
+                bcm43xx_voluntary_preempt();
         } else
                 bcm43xx_phy_write(bcm, 0x0015, r27 | 0xEFA0);
         bcm43xx_phy_lo_adjust(bcm, is_initializing);
@@ -2188,12 +2198,6 @@ int bcm43xx_phy_init(struct bcm43xx_private *bcm)
 {
         struct bcm43xx_phyinfo *phy = bcm43xx_current_phy(bcm);
         int err = -ENODEV;
-        unsigned long flags;
-
-        /* We do not want to be preempted while calibrating
-         * the hardware.
-         */
-        local_irq_save(flags);
 
         switch (phy->type) {
         case BCM43xx_PHYTYPE_A:
@@ -2227,7 +2231,6 @@ int bcm43xx_phy_init(struct bcm43xx_private *bcm)
                 err = 0;
                 break;
         }
-        local_irq_restore(flags);
         if (err)
                 printk(KERN_WARNING PFX "Unknown PHYTYPE found!\n");