[ 022/124] b43: N-PHY: use more bits for offset in RSSI calibration

From: Greg Kroah-Hartman
Date: Tue Apr 02 2013 - 19:19:09 EST


3.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: RafaÅ MiÅecki <zajec5@xxxxxxxxx>

commit 2e1253d640eb7f8707d2591c93097c1e9f9c71d5 upstream.

When calculating "offset" for final RSSI calibration we're using numbers
bigger than s8 can hold. We have for example:
offset[j] = 232 - poll_results[j];
formula. If poll_results[j] is small enough (it usually is) we treat
number's bit as a sign bit. For example 232 - 1 becomes:
0xE8 - 0x1 = 0xE7, which is not 231 but -25.

This code was introduced in e0c9a0219a8f542e3946fe972a68aacf8c3f906c
and caused stability regression on some cards, for ex. BCM4322.

Signed-off-by: RafaÅ MiÅecki <zajec5@xxxxxxxxx>
Signed-off-by: John W. Linville <linville@xxxxxxxxxxxxx>

---
drivers/net/wireless/b43/phy_n.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/wireless/b43/phy_n.c
+++ b/drivers/net/wireless/b43/phy_n.c
@@ -1564,7 +1564,7 @@ static void b43_nphy_rev3_rssi_cal(struc
u16 clip_off[2] = { 0xFFFF, 0xFFFF };

u8 vcm_final = 0;
- s8 offset[4];
+ s32 offset[4];
s32 results[8][4] = { };
s32 results_min[4] = { };
s32 poll_results[4] = { };
@@ -1732,7 +1732,7 @@ static void b43_nphy_rev2_rssi_cal(struc
u8 regs_save_radio[2];
u16 regs_save_phy[2];

- s8 offset[4];
+ s32 offset[4];
u8 core;
u8 rail;



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