Re: [PATCH 5/5] I/OAT: Add completion callback for async_tx interface use

[Andrew Morton <akpm@linux-foundation.org>]

On Wed, 17 Oct 2007 17:14:39 -0700
Shannon Nelson <shannon.nelson@intel.com> wrote:

> +	printk(KERN_ERR "ioatdma: ioat_dma_test_callback(0x%04llx)\n",
> +		(u64)dma_async_param);

Generates a warning on 32-bit:

drivers/dma/ioat_dma.c: In function 'ioat_dma_test_callback':
drivers/dma/ioat_dma.c:660: warning: cast from pointer to integer of different size

and we can never ever print u64's anwyay: we dont' know what type the arch
uses to implement them.  The usual fix is to cast to unsigned long long,
but in this case %p will work nicely, no?

> +	tx->callback = (void *)ioat_dma_test_callback;

and when I remove this cast I get

drivers/dma/ioat_dma.c: In function 'ioat_dma_self_test':
drivers/dma/ioat_dma.c:718: warning: assignment from incompatible pointer type

because ioat_dma_test_callback isn't void-returning.  Something is wrong
here.  I assume that ioat_dma_test_callback() should just be
void-returning?



diff -puN drivers/dma/ioat_dma.c~i-oat-add-completion-callback-for-async_tx-interface-use-fix drivers/dma/ioat_dma.c
--- a/drivers/dma/ioat_dma.c~i-oat-add-completion-callback-for-async_tx-interface-use-fix
+++ a/drivers/dma/ioat_dma.c
@@ -654,11 +654,10 @@ static void ioat_dma_start_null_desc(str
  */
 #define IOAT_TEST_SIZE 2000
 
-static dma_async_tx_callback ioat_dma_test_callback(void *dma_async_param)
+static void ioat_dma_test_callback(void *dma_async_param)
 {
-	printk(KERN_ERR "ioatdma: ioat_dma_test_callback(0x%04llx)\n",
-		(u64)dma_async_param);
-	return 0;
+	printk(KERN_ERR "ioatdma: ioat_dma_test_callback(0x%p)\n",
+			dma_async_param);
 }
 
 /**
@@ -715,7 +714,7 @@ static int ioat_dma_self_test(struct ioa
 	addr = dma_map_single(dma_chan->device->dev, dest, IOAT_TEST_SIZE,
 			DMA_FROM_DEVICE);
 	ioat_set_dest(addr, tx, 0);
-	tx->callback = (void *)ioat_dma_test_callback;
+	tx->callback = ioat_dma_test_callback;
 	tx->callback_param = (void *)0x8086;
 	cookie = ioat_tx_submit(tx);
 	if (cookie < 0) {
_