b43: Rewrite TX power adjustment

This patch rewrites the TX power recalculation algorithms to scale better
with changed enviromnent. If there's low
TX traffic, the power will be checked against the desired values
every 60 seconds.
If there is high TX traffic, the check is redone every 2 seconds. This improves
the reaction times a lot and confuses the rate control less.
It will also reduce the time it initially takes to tune to a new TX power
value. With the old algorithm it could take about 30 to 45 seconds to settle to
a new power value. This will happen in about two to four seconds now.

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

1 files changed, 91 insertions, 0 deletions

diff --git a/drivers/net/wireless/b43/phy_common.c b/drivers/net/wireless/b43/phy_common.c
index 45074c05d51d..5a550a7af2e9 100644
--- a/drivers/net/wireless/b43/phy_common.c
+++ b/drivers/net/wireless/b43/phy_common.c
@@ -274,3 +274,94 @@ void b43_software_rfkill(struct b43_wldev *dev, enum rfkill_state state)
         phy->ops->software_rfkill(dev, state);
         phy->radio_on = (state == RFKILL_STATE_UNBLOCKED);
 }
+
+/**
+ * b43_phy_txpower_adjust_work - TX power workqueue.
+ *
+ * Workqueue for updating the TX power parameters in hardware.
+ */
+void b43_phy_txpower_adjust_work(struct work_struct *work)
+{
+        struct b43_wl *wl = container_of(work, struct b43_wl,
+                                         txpower_adjust_work);
+        struct b43_wldev *dev;
+
+        mutex_lock(&wl->mutex);
+        dev = wl->current_dev;
+
+        if (likely(dev && (b43_status(dev) >= B43_STAT_STARTED)))
+                dev->phy.ops->adjust_txpower(dev);
+
+        mutex_unlock(&wl->mutex);
+}
+
+/* Called with wl->irq_lock locked */
+void b43_phy_txpower_check(struct b43_wldev *dev, unsigned int flags)
+{
+        struct b43_phy *phy = &dev->phy;
+        unsigned long now = jiffies;
+        enum b43_txpwr_result result;
+
+        if (!(flags & B43_TXPWR_IGNORE_TIME)) {
+                /* Check if it's time for a TXpower check. */
+                if (time_before(now, phy->next_txpwr_check_time))
+                        return; /* Not yet */
+        }
+        /* The next check will be needed in two seconds, or later. */
+        phy->next_txpwr_check_time = round_jiffies(now + (HZ * 2));
+
+        if ((dev->dev->bus->boardinfo.vendor == SSB_BOARDVENDOR_BCM) &&
+            (dev->dev->bus->boardinfo.type == SSB_BOARD_BU4306))
+                return; /* No software txpower adjustment needed */
+
+        result = phy->ops->recalc_txpower(dev, !!(flags & B43_TXPWR_IGNORE_TSSI));
+        if (result == B43_TXPWR_RES_DONE)
+                return; /* We are done. */
+        B43_WARN_ON(result != B43_TXPWR_RES_NEED_ADJUST);
+        B43_WARN_ON(phy->ops->adjust_txpower == NULL);
+
+        /* We must adjust the transmission power in hardware.
+         * Schedule b43_phy_txpower_adjust_work(). */
+        queue_work(dev->wl->hw->workqueue, &dev->wl->txpower_adjust_work);
+}
+
+int b43_phy_shm_tssi_read(struct b43_wldev *dev, u16 shm_offset)
+{
+        const bool is_ofdm = (shm_offset != B43_SHM_SH_TSSI_CCK);
+        unsigned int a, b, c, d;
+        unsigned int average;
+        u32 tmp;
+
+        tmp = b43_shm_read32(dev, B43_SHM_SHARED, shm_offset);
+        a = tmp & 0xFF;
+        b = (tmp >> 8) & 0xFF;
+        c = (tmp >> 16) & 0xFF;
+        d = (tmp >> 24) & 0xFF;
+        if (a == 0 || a == B43_TSSI_MAX ||
+            b == 0 || b == B43_TSSI_MAX ||
+            c == 0 || c == B43_TSSI_MAX ||
+            d == 0 || d == B43_TSSI_MAX)
+                return -ENOENT;
+        /* The values are OK. Clear them. */
+        tmp = B43_TSSI_MAX | (B43_TSSI_MAX << 8) |
+              (B43_TSSI_MAX << 16) | (B43_TSSI_MAX << 24);
+        b43_shm_write32(dev, B43_SHM_SHARED, shm_offset, tmp);
+
+        if (is_ofdm) {
+                a = (a + 32) & 0x3F;
+                b = (b + 32) & 0x3F;
+                c = (c + 32) & 0x3F;
+                d = (d + 32) & 0x3F;
+        }
+
+        /* Get the average of the values with 0.5 added to each value. */
+        average = (a + b + c + d + 2) / 4;
+        if (is_ofdm) {
+                /* Adjust for CCK-boost */
+                if (b43_shm_read16(dev, B43_SHM_SHARED, B43_SHM_SH_HOSTFLO)
+                    & B43_HF_CCKBOOST)
+                        average = (average >= 13) ? (average - 13) : 0;
+        }
+
+        return average;
+}