On 1/7/24 9:02 PM, Phillip Susi wrote:
> When a disk is in SLEEP mode it can not respond to any
> any commands. Several commands are simply a NOOP to a disk
> that is in standby mode, but when a disk is in SLEEP mode,
> they frequencly cause the disk to spin up for no reason.
Frequently.
> To avoid this, complete these commands in libata without
> waking the disk. These commands are:
>
> CHECK POWER MODE
> FLUSH CACHE
> SLEEP
> STANDBY IMMEDIATE
> IDENTIFY
>
> If we know the disk is sleeping, we don't need to wake it up
> to find out if it is in standby, so just pretend it is in
> standby. While asleep, there's no dirty pages in the cache,
> so there's no need to flush it. There's no point in waking
> a disk from sleep just to put it back to sleep. We also have
> a cache of the IDENTIFY information so just return that
> instead of waking the disk.
[...]
Did you run your patches thru scripts/checkpatch.pl? Looking
at this patch, I think you didn't... :-)
> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> index 09ed67772fae..6c5269de4bf2 100644
> --- a/drivers/ata/libata-core.c
> +++ b/drivers/ata/libata-core.c
> @@ -5040,6 +5040,26 @@ void ata_qc_issue(struct ata_queued_cmd *qc)
>
> /* if device is sleeping, schedule reset and abort the link */
> if (unlikely(qc->dev->flags & ATA_DFLAG_SLEEPING)) {
> + switch (qc->tf.command)
> + {
switch (qc->tf.command) {
> + case ATA_CMD_CHK_POWER:
> + case ATA_CMD_SLEEP:
> + case ATA_CMD_FLUSH:
> + case ATA_CMD_FLUSH_EXT:
> + case ATA_CMD_STANDBYNOW1:
> + if (qc->tf.command == ATA_CMD_ID_ATA)
This can't happen, you forgot:
case ATA_CMD_ID_ATA:
> + {
if (qc->tf.command == ATA_CMD_ID_ATA) {
> + /* only fake the reply for IDENTIFY if it is from userspace */
> + if (ata_tag_internal(qc->tag))
> + break;
> + sg_copy_from_buffer(qc->sg, 1, qc->dev->id, 2 * ATA_ID_WORDS);
> + }
> + /* fake reply to avoid waking drive */
> + qc->flags |= ATA_QCFLAG_RTF_FILLED;
> + qc->result_tf.nsect = 0;
> + ata_qc_complete(qc);
> + return;
> + }
> link->eh_info.action |= ATA_EH_RESET;
> ata_ehi_push_desc(&link->eh_info, "waking up from sleep");
> ata_link_abort(link);
MBR, Sergey
