[Skiboot] [SKIBOOT] [PATCH] pflash: Fix erase command for unaligned start address

[Cyril Bur]

On Wed, 2017-09-13 at 16:59 +1000, Suraj Jitindar Singh wrote:
> The erase_range() function handles erasing the flash for a given start
> address and length, and can handle an unaligned start address and
> length. However in the unaligned start address case we are incorrectly
> calculating the remaining size which can lead to incomplete erases.
> 
> If we're going to update the remaining size based on what the start
> address was then we probably want to do that before we overide the
> origin start address. So rearrange the code so that this is indeed the
> case.
> 
> Reported-by: Pridhiviraj Paidipeddi <ppaidipe at in.ibm.com>
> Signed-off-by: Suraj Jitindar Singh <sjitindarsingh at gmail.com>

Good find.
Stewart: I know you usually do, but just to be sure, if you could
respond with the merged sha1 of this so that I'll remember to add a
testcase for this, I'm surprised this wasn't caught in testing.

Reviewed-by: Cyril Bur <cyril.bur at au1.ibm.com>

> ---
>  external/pflash/pflash.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/external/pflash/pflash.c b/external/pflash/pflash.c
> index bfc975f..5b1be3c 100644
> --- a/external/pflash/pflash.c
> +++ b/external/pflash/pflash.c
> @@ -331,9 +331,9 @@ static int erase_range(struct flash_details *flash,
>  			fprintf(stderr, "Failed to blocklevel_smart_erase(): %d\n", rc);
>  			return 1;
>  		}
> -		start += flash->erase_granule - (start & erase_mask);
>  		size -= flash->erase_granule - (start & erase_mask);
>  		done = flash->erase_granule - (start & erase_mask);
> +		start += flash->erase_granule - (start & erase_mask);
>  	}
>  	progress_tick(done);
>  	while (size & ~(erase_mask)) {