b43: Rewrite LO calibration algorithm

This patch distributes the Local Oscillator calibration bursts over time,
so that calibration only happens when it's actually needed.
Currently we periodically perform a recalibration of the whole table.
The table is huge and this takes lots of time. Additionally only small bits
of the table are actually needed at a given time. So instead of maintaining
a huge table with all possible calibration values, we create dynamic calibration
settings that
a) We only calibrate when they are actually needed.
b) Are cached for some time until they expire.
So a recalibration might happen if we need a calibration setting that's not
cached, or if the active calibration setting expires.
Currently the expire timeout is set to 30 seconds. We may raise that in future.

This patch reduces overall memory consumption by nuking the
huge static calibration tables.

This patch has been tested on several 4306, 4311 and 4318 flavours.

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

1 files changed, 44 insertions, 71 deletions

diff --git a/drivers/net/wireless/b43/lo.h b/drivers/net/wireless/b43/lo.h
index 455615d1f8c..1da321cabc1 100644
--- a/drivers/net/wireless/b43/lo.h
+++ b/drivers/net/wireless/b43/lo.h
@@ -10,82 +10,63 @@ struct b43_loctl {
 	/* Control values. */
 	s8 i;
 	s8 q;
-	/* "Used by hardware" flag. */
-	bool used;
-#ifdef CONFIG_B43_DEBUG
-	/* Is this lo-control-array entry calibrated? */
-	bool calibrated;
-#endif
 };
-
 /* Debugging: Poison value for i and q values. */
 #define B43_LOCTL_POISON	111
 
-/* loctl->calibrated debugging mechanism */
-#ifdef CONFIG_B43_DEBUG
-static inline void b43_loctl_set_calibrated(struct b43_loctl *loctl,
-					    bool calibrated)
-{
-	loctl->calibrated = calibrated;
-}
-static inline bool b43_loctl_is_calibrated(struct b43_loctl *loctl)
-{
-	return loctl->calibrated;
-}
-#else
-static inline void b43_loctl_set_calibrated(struct b43_loctl *loctl,
-					    bool calibrated)
-{
-}
-static inline bool b43_loctl_is_calibrated(struct b43_loctl *loctl)
-{
-	return 1;
-}
-#endif
-
-/* TX Power LO Control Array.
- * Value-pairs to adjust the LocalOscillator are stored
- * in this structure.
- * There are two different set of values. One for "Flag is Set"
- * and one for "Flag is Unset".
- * By "Flag" the flag in struct b43_rfatt is meant.
- * The Value arrays are two-dimensional. The first index
- * is the baseband attenuation and the second index
- * is the radio attenuation.
- * Use b43_get_lo_g_ctl() to retrieve a value from the lists.
- */
+/* This struct holds calibrated LO settings for a set of
+ * Baseband and RF attenuation settings. */
+struct b43_lo_calib {
+	/* The set of attenuation values this set of LO
+	 * control values is calibrated for. */
+	struct b43_bbatt bbatt;
+	struct b43_rfatt rfatt;
+	/* The set of control values for the LO. */
+	struct b43_loctl ctl;
+	/* The time when these settings were calibrated (in jiffies) */
+	unsigned long calib_time;
+	/* List. */
+	struct list_head list;
+};
+
+/* Size of the DC Lookup Table in 16bit words. */
+#define B43_DC_LT_SIZE		32
+
+/* Local Oscillator calibration information */
 struct b43_txpower_lo_control {
-#define B43_NR_BB	12
-#define B43_NR_RF	16
-	/* LO Control values, with PAD Mixer */
-	struct b43_loctl with_padmix[B43_NR_BB][B43_NR_RF];
-	/* LO Control values, without PAD Mixer */
-	struct b43_loctl no_padmix[B43_NR_BB][B43_NR_RF];
-
-	/* Flag to indicate a complete rebuild of the two tables above
-	 * to the LO measuring code. */
-	bool rebuild;
-
-	/* Lists of valid RF and BB attenuation values for this device. */
+	/* Lists of RF and BB attenuation values for this device.
+	 * Used for building hardware power control tables. */
 	struct b43_rfatt_list rfatt_list;
 	struct b43_bbatt_list bbatt_list;
 
+	/* The DC Lookup Table is cached in memory here.
+	 * Note that this is only used for Hardware Power Control. */
+	u16 dc_lt[B43_DC_LT_SIZE];
+
+	/* List of calibrated control values (struct b43_lo_calib). */
+	struct list_head calib_list;
+	/* Last time the power vector was read (jiffies). */
+	unsigned long pwr_vec_read_time;
+	/* Last time the txctl values were measured (jiffies). */
+	unsigned long txctl_measured_time;
+
 	/* Current TX Bias value */
 	u8 tx_bias;
 	/* Current TX Magnification Value (if used by the device) */
 	u8 tx_magn;
 
-	/* GPHY LO is measured. */
-	bool lo_measured;
-
 	/* Saved device PowerVector */
 	u64 power_vector;
 };
 
-/* Measure the BPHY Local Oscillator. */
-void b43_lo_b_measure(struct b43_wldev *dev);
-/* Measure the BPHY/GPHY Local Oscillator. */
-void b43_lo_g_measure(struct b43_wldev *dev);
+/* Calibration expire timeouts.
+ * Timeouts must be multiple of 15 seconds. To make sure
+ * the item really expired when the 15 second timer hits, we
+ * subtract two additional seconds from the timeout. */
+#define B43_LO_CALIB_EXPIRE	(HZ * (30 - 2))
+#define B43_LO_PWRVEC_EXPIRE	(HZ * (30 - 2))
+#define B43_LO_TXCTL_EXPIRE	(HZ * (180 - 4))
+
 
 /* Adjust the Local Oscillator to the saved attenuation
  * and txctl values.
@@ -95,18 +76,10 @@ void b43_lo_g_adjust(struct b43_wldev *dev);
 void b43_lo_g_adjust_to(struct b43_wldev *dev,
 			u16 rfatt, u16 bbatt, u16 tx_control);
 
-/* Mark all possible b43_lo_g_ctl as "unused" */
-void b43_lo_g_ctl_mark_all_unused(struct b43_wldev *dev);
-/* Mark the b43_lo_g_ctl corresponding to the current
- * attenuation values as used.
- */
-void b43_lo_g_ctl_mark_cur_used(struct b43_wldev *dev);
+void b43_gphy_dc_lt_init(struct b43_wldev *dev, bool update_all);
 
-/* Get a reference to a LO Control value pair in the
- * TX Power LO Control Array.
- */
-struct b43_loctl *b43_get_lo_g_ctl(struct b43_wldev *dev,
-				   const struct b43_rfatt *rfatt,
-				   const struct b43_bbatt *bbatt);
+void b43_lo_g_maintanance_work(struct b43_wldev *dev);
+void b43_lo_g_cleanup(struct b43_wldev *dev);
+void b43_lo_g_init(struct b43_wldev *dev);
 
 #endif /* B43_LO_H_ */