ath5k: correct channel setting for 2.5 mhz spacing

These channels aren't selectable anyway, but our calculations
for 2.5 mhz frequencies are incorrect.  The value is supposed to
be:

  (frequency - reference) * (10/25)

i.e., divide by 2.5, but we were instead doing:

  (10 * frequency - reference) / 25.

Additionally, the check for (frequency % 5 == 2) had an extra
subtraction that wasn't in madwifi HAL.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
Acked-by: Bruno Randolf <br1@einfach.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/net/wireless/ath/ath5k/phy.c b/drivers/net/wireless/ath/ath5k/phy.c
index b6704c93f808..fcfc32d4da20 100644
--- a/drivers/net/wireless/ath/ath5k/phy.c
+++ b/drivers/net/wireless/ath/ath5k/phy.c
@@ -979,7 +979,7 @@ static int ath5k_hw_rf5112_channel(struct ath5k_hw *ah,
                         return -EINVAL;
 
                 data0 = ath5k_hw_bitswap((data0 << 2) & 0xff, 8);
-        } else if ((c - (c % 5)) != 2 || c > 5435) {
+        } else if ((c % 5) != 2 || c > 5435) {
                 if (!(c % 20) && c >= 5120) {
                         data0 = ath5k_hw_bitswap(((c - 4800) / 20 << 2), 8);
                         data2 = ath5k_hw_bitswap(3, 2);
@@ -992,7 +992,7 @@ static int ath5k_hw_rf5112_channel(struct ath5k_hw *ah,
                 } else
                         return -EINVAL;
         } else {
-                data0 = ath5k_hw_bitswap((10 * (c - 2) - 4800) / 25 + 1, 8);
+                data0 = ath5k_hw_bitswap((10 * (c - 2 - 4800)) / 25 + 1, 8);
                 data2 = ath5k_hw_bitswap(0, 2);
         }
 
@@ -1020,7 +1020,7 @@ static int ath5k_hw_rf2425_channel(struct ath5k_hw *ah,
                 data0 = ath5k_hw_bitswap((c - 2272), 8);
                 data2 = 0;
         /* ? 5GHz ? */
-        } else if ((c - (c % 5)) != 2 || c > 5435) {
+        } else if ((c % 5) != 2 || c > 5435) {
                 if (!(c % 20) && c < 5120)
                         data0 = ath5k_hw_bitswap(((c - 4800) / 20 << 2), 8);
                 else if (!(c % 10))
@@ -1031,7 +1031,7 @@ static int ath5k_hw_rf2425_channel(struct ath5k_hw *ah,
                         return -EINVAL;
                 data2 = ath5k_hw_bitswap(1, 2);
         } else {
-                data0 = ath5k_hw_bitswap((10 * (c - 2) - 4800) / 25 + 1, 8);
+                data0 = ath5k_hw_bitswap((10 * (c - 2 - 4800)) / 25 + 1, 8);
                 data2 = ath5k_hw_bitswap(0, 2);
         }