On 2/2/22 05:51, Sergey Shtylyov wrote:
> ata_std_prereset() always returns 0, hence the check in ata_sff_prereset()
> is pointless and thus it also can return only 0 (however, we cannot change
> the prototypes of ata_{sff|std}_prereset() as they implement the driver's
> prereset() method).
>
> Found by Linux Verification Center (linuxtesting.org) with the SVACE static
> analysis tool.
>
> Signed-off-by: Sergey Shtylyov <s.shtylyov@xxxxxx>
>
> ---
> This patch is against the 'for-next' branch of Damien Le Moal's 'libata.git'
> repo.
>
> Changes in version 2:
> - fixed up the 'kernel-doc' comments on the function results.
>
> drivers/ata/libata-core.c | 2 +-
> drivers/ata/libata-sff.c | 6 ++----
> 2 files changed, 3 insertions(+), 5 deletions(-)
>
> Index: libata/drivers/ata/libata-core.c
> ===================================================================
> --- libata.orig/drivers/ata/libata-core.c
> +++ libata/drivers/ata/libata-core.c
> @@ -3568,7 +3568,7 @@ EXPORT_SYMBOL_GPL(ata_wait_after_reset);
> * Kernel thread context (may sleep)
> *
> * RETURNS:
> - * 0 on success, -errno otherwise.
> + * Always 0.
> */
> int ata_std_prereset(struct ata_link *link, unsigned long deadline)
> {
> Index: libata/drivers/ata/libata-sff.c
> ===================================================================
> --- libata.orig/drivers/ata/libata-sff.c
> +++ libata/drivers/ata/libata-sff.c
> @@ -1708,16 +1708,14 @@ EXPORT_SYMBOL_GPL(ata_sff_thaw);
> * Kernel thread context (may sleep)
> *
> * RETURNS:
> - * 0 on success, -errno otherwise.
> + * Always 0.
> */
> int ata_sff_prereset(struct ata_link *link, unsigned long deadline)
> {
> struct ata_eh_context *ehc = &link->eh_context;
> int rc;
>
> - rc = ata_std_prereset(link, deadline);
> - if (rc)
> - return rc;
> + ata_std_prereset(link, deadline);
Not a fan of removing the check here unless ata_std_prereset() is turned
into a void function. But doing that needs more changes with little
value. So at least can you add a comment above this call ? Something like:
/* Standard prereset is best-effort and always return 0 */
ata_std_prereset(link, deadline);
So that it is clear that we are aware that the function is non-void ?
>
> /* if we're about to do hardreset, nothing more to do */
> if (ehc->i.action & ATA_EH_HARDRESET)
--
Damien Le Moal
Western Digital Research
