Subject: Re: [PATCH 2/2] powerpc/msi: Use WARN_ON() in msi bitmap selftests

From: Laurentiu Tudor <[email-masked]>
Date: Fri, 10 Oct 2014 11:11:46 +0300

Hi Michael,

Comment inline.

On 10/10/2014 11:04 AM, Michael Ellerman wrote:
> As demonstrated in the previous commit, the failure message from the msi
> bitmap selftests is a bit subtle, it's easy to miss a failure in a busy
> boot log.
> 
> So drop our check() macro and use WARN_ON() instead. This necessitates
> inverting all the conditions as well.
> 
> Signed-off-by: Michael Ellerman <[email-masked]>
> ---
>  arch/powerpc/sysdev/msi_bitmap.c | 54 ++++++++++++++++++----------------------

[snip]

>  
>  	/* Free most of them for the alignment tests */
>  	msi_bitmap_free_hwirqs(&bmp, 3, size - 3);
>  
>  	/* Check we get a naturally aligned offset */
>  	rc = msi_bitmap_alloc_hwirqs(&bmp, 2);
> -	check(rc >= 0 && rc % 2 == 0);
> +	WARN_ON(rc < 0 && rc % 2 != 0);

Here and below, shouldn't these be:

	WARN_ON(rc < 0 || rc % 2 != 0);

?

>  	rc = msi_bitmap_alloc_hwirqs(&bmp, 4);
> -	check(rc >= 0 && rc % 4 == 0);
> +	WARN_ON(rc < 0 && rc % 4 != 0);
>  	rc = msi_bitmap_alloc_hwirqs(&bmp, 8);
> -	check(rc >= 0 && rc % 8 == 0);
> +	WARN_ON(rc < 0 && rc % 8 != 0);
>  	rc = msi_bitmap_alloc_hwirqs(&bmp, 9);
> -	check(rc >= 0 && rc % 16 == 0);
> +	WARN_ON(rc < 0 && rc % 16 != 0);
>  	rc = msi_bitmap_alloc_hwirqs(&bmp, 3);
> -	check(rc >= 0 && rc % 4 == 0);
> +	WARN_ON(rc < 0 && rc % 4 != 0);
>  	rc = msi_bitmap_alloc_hwirqs(&bmp, 7);
> -	check(rc >= 0 && rc % 8 == 0);
> +	WARN_ON(rc < 0 && rc % 8 != 0);
>  	rc = msi_bitmap_alloc_hwirqs(&bmp, 121);
> -	check(rc >= 0 && rc % 128 == 0);
> +	WARN_ON(rc < 0 && rc % 128 != 0);
>  
>  	msi_bitmap_free(&bmp);
>  
> -	/* Clients may check bitmap == NULL for "not-allocated" */
> -	check(bmp.bitmap == NULL);
> +	/* Clients may WARN_ON bitmap == NULL for "not-allocated" */
> +	WARN_ON(bmp.bitmap != NULL);
>  
>  	kfree(bmp.bitmap);
>  }
> @@ -229,14 +224,13 @@ static void __init test_of_node(void)
>  	of_node_init(&of_node);
>  	of_node.full_name = node_name;
>  
> -	check(0 == msi_bitmap_alloc(&bmp, size, &of_node));
> +	WARN_ON(msi_bitmap_alloc(&bmp, size, &of_node));
>  
>  	/* No msi-available-ranges, so expect > 0 */
> -	check(msi_bitmap_reserve_dt_hwirqs(&bmp) > 0);
> +	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);
>  
>  	/* Should all still be free */
> -	check(0 == bitmap_find_free_region(bmp.bitmap, size,
> -					   get_count_order(size)));
> +	WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size)));
>  	bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
>  
>  	/* Now create a fake msi-available-ranges property */
> @@ -250,11 +244,11 @@ static void __init test_of_node(void)
>  	of_node.properties = &prop;
>  
>  	/* msi-available-ranges, so expect == 0 */
> -	check(msi_bitmap_reserve_dt_hwirqs(&bmp) == 0);
> +	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp));
>  
>  	/* Check we got the expected result */
> -	check(0 == bitmap_parselist(expected_str, expected, size));
> -	check(bitmap_equal(expected, bmp.bitmap, size));
> +	WARN_ON(bitmap_parselist(expected_str, expected, size));
> +	WARN_ON(!bitmap_equal(expected, bmp.bitmap, size));
>  
>  	msi_bitmap_free(&bmp);
>  	kfree(bmp.bitmap);
> 

---
Best Regards, Laurentiu