On Mon, Jul 07, 2014 at 09:49:45AM -0400, Tejun Heo wrote:
> Hello,
>
> On Sun, Jul 06, 2014 at 02:28:40PM +0800, Kevin Hao wrote:
> > +int ata_host_set_queue_depth(struct ata_host *host, unsigned int queue_depth)
>
> Hmmm... is there a reason we're doing this separately when the same
> information is available from scsi_host_template->can_queue from
> ata_host_register()?
This was my first thought. But given that scsi_host_template are the parameters
passed to the scsi layer, it seems a bit weird to set the ata_host based a
value in that. Anyway if we decide to use can_queue, how about directly use
it in ata_qc_new(), just like the following codes?
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 8f3043165048..4792fea79acf 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4728,14 +4728,17 @@ void swap_buf_le16(u16 *buf, unsigned int buf_words)
static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
{
struct ata_queued_cmd *qc = NULL;
- unsigned int i, tag;
+ unsigned int i, tag, max_queue;
+
+ max_queue = ap->scsi_host->can_queue;
+ WARN_ON_ONCE(max_queue > ATA_MAX_QUEUE);
/* no command while frozen */
if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
return NULL;
- for (i = 0; i < ATA_MAX_QUEUE; i++) {
- tag = (i + ap->last_tag + 1) % ATA_MAX_QUEUE;
+ for (i = 0, tag = ap->last_tag + 1; i < max_queue; i++, tag++) {
+ tag = tag < max_queue ? tag : 0;
/* the last tag is reserved for internal command. */
if (tag == ATA_TAG_INTERNAL)
Thanks,
Kevin
Attachment:
pgpZmnkaHxEKr.pgp
Description: PGP signature
