wl1271: Clean up firmware block allocation calculation

This patch simplifies the required block count calculation. Though it
introduces a division operator, it greatly simplifies the formula.

Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: Teemu Paasikivi <ext-teemu.3.paasikivi@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 4 insertions, 8 deletions

diff --git a/drivers/net/wireless/wl12xx/wl1271_tx.c b/drivers/net/wireless/wl12xx/wl1271_tx.c
index a32d3014781d..d3ed63e92cf4 100644
--- a/drivers/net/wireless/wl12xx/wl1271_tx.c
+++ b/drivers/net/wireless/wl12xx/wl1271_tx.c
@@ -46,7 +46,7 @@ static int wl1271_tx_allocate(struct wl1271 *wl, struct sk_buff *skb, u32 extra)
 {
         struct wl1271_tx_hw_descr *desc;
         u32 total_len = skb->len + sizeof(struct wl1271_tx_hw_descr) + extra;
-        u32 total_blocks, excluded;
+        u32 total_blocks;
         int id, ret = -EBUSY;
 
         /* allocate free identifier for the packet */
@@ -56,12 +56,8 @@ static int wl1271_tx_allocate(struct wl1271 *wl, struct sk_buff *skb, u32 extra)
 
         /* approximate the number of blocks required for this packet
            in the firmware */
-        /* FIXME: try to figure out what is done here and make it cleaner */
-        total_blocks = (total_len + 20) >> TX_HW_BLOCK_SHIFT_DIV;
-        excluded = (total_blocks << 2) + ((total_len + 20) & 0xff) + 34;
-        total_blocks += (excluded > 252) ? 2 : 1;
-        total_blocks += TX_HW_BLOCK_SPARE;
-
+        total_blocks = total_len + TX_HW_BLOCK_SIZE - 1;
+        total_blocks = total_blocks / TX_HW_BLOCK_SIZE + TX_HW_BLOCK_SPARE;
         if (total_blocks <= wl->tx_blocks_available) {
                 desc = (struct wl1271_tx_hw_descr *)skb_push(
                         skb, total_len - skb->len);
diff --git a/drivers/net/wireless/wl12xx/wl1271_tx.h b/drivers/net/wireless/wl12xx/wl1271_tx.h
index ca92bd811292..8b9f6b4f5652 100644
--- a/drivers/net/wireless/wl12xx/wl1271_tx.h
+++ b/drivers/net/wireless/wl12xx/wl1271_tx.h
@@ -26,7 +26,7 @@
 #define __WL1271_TX_H__
 
 #define TX_HW_BLOCK_SPARE                2
-#define TX_HW_BLOCK_SHIFT_DIV            8
+#define TX_HW_BLOCK_SIZE                 252
 
 #define TX_HW_MGMT_PKT_LIFETIME_TU       2000
 /* The chipset reference driver states, that the "aid" value 1