[PATCH] b43: Add slot count compiletime assertion

[PATCH] b43: Add slot count compiletime assertion

[Michael Buesch]

This adds a compiletime assertion for a recently introduced
assumption on the slot counts.
The tx header cache handling code assumes that the TX slot count
can be divided evenly by the number of TX slots per frame.

Signed-off-by: Michael Buesch <mb@bu3sch.de>

---

Please queue on top of the DMA optimizations.


Index: wireless-testing/drivers/net/wireless/b43/dma.c
===================================================================
--- wireless-testing.orig/drivers/net/wireless/b43/dma.c	2009-02-19 23:34:25.000000000 +0100
+++ wireless-testing/drivers/net/wireless/b43/dma.c	2009-02-20 00:03:30.000000000 +0100
@@ -839,12 +839,16 @@ struct b43_dmaring *b43_setup_dmaring(st
 	spin_lock_init(&ring->lock);
 #ifdef CONFIG_B43_DEBUG
 	ring->last_injected_overflow = jiffies;
 #endif
 
 	if (for_tx) {
+		/* Assumption: B43_TXRING_SLOTS can be divided by TX_SLOTS_PER_FRAME */
+		BUILD_BUG_ON((B43_TXRING_SLOTS * 1000000) / TX_SLOTS_PER_FRAME !=
+			     (B43_TXRING_SLOTS / TX_SLOTS_PER_FRAME) * 1000000);
+
 		ring->txhdr_cache = kcalloc(ring->nr_slots / TX_SLOTS_PER_FRAME,
 					    b43_txhdr_size(dev),
 					    GFP_KERNEL);
 		if (!ring->txhdr_cache)
 			goto err_kfree_meta;
 

-- 
Greetings, Michael.

Re: [PATCH] b43: Add slot count compiletime assertion

[Michael Buesch]

On Friday 20 February 2009 00:09:42 Michael Buesch wrote:
> This adds a compiletime assertion for a recently introduced
> assumption on the slot counts.
> The tx header cache handling code assumes that the TX slot count
> can be divided evenly by the number of TX slots per frame.
> 
> Signed-off-by: Michael Buesch <mb@bu3sch.de>
> 
> ---
> 
> Please queue on top of the DMA optimizations.

I wonder what I was smoking when doing this patch, yesterday.

I'll immediately get a brown paper bag and redo a sane version of this... :)


-- 
Greetings, Michael.