Tejun Heo wrote:
Tejun Heo wrote:
Jeff Garzik wrote:
Tejun Heo wrote:
Add dev->acpi_init_gtm and store initial GTM values on host
initialization. If the field is valid, ATA_PFLAG_INIT_GTM_VALID flag
is set. This is to remember BIOS/firmware programmed initial timing
for later use before reset and mode configuration modify it.
Signed-off-by: Tejun Heo <htejun@xxxxxxxxx>
It sounds like pata_via and pata_amd need a foo_save_initial_config()
much like AHCI, during which they would fill ppriv->init_gtm rather than
ap->init_gtm. Thoughts? Both drivers are calling ata_acpi_cbl()
themselves, permitting the possibility of ppriv->init_gtm.
This avoids forcing everyone else to bear the memory cost in ata_port
for just these two drivers.
The memory overhead is pretty small and more importantly there isn't a
good place to load initial GTM. ACPI is associated with the host during
host registration after all private host initialization is complete.
When the EH gets invoked, the first thing which is done is forcing PIO0
before initial reset.
Unless we add another hook, the only place to put this is in private
->error_handler(). A driver can check whether it's being called for the
first time and record it in private structure, which isn't too pretty,
so I thought doing it this way was fair tradeoff.
Jeff, do you agree or still think it's better done in LLDs? I'm okay
either way.
I trust your judgement... My reply was more of a "gut feeling" sort of
thing.
In general, I want to keep libata as close as possible to the "LLD
call-out model" as possible: LLD registers itself with system services
[perhaps using generic helpers to do so]. LLD fills in its own scsi
host template and ata_port_operations [perhaps using generic helpers to
do so]. LLD implements specific helpers that control LLD-specific
behavior, calling out to libata helpers as need arises.
So I tend to prefer adding direct LLD control points to ATA_FLAG_xxx
control points or other solutions, if the situation permits me to choose.
If you have to ask... I will always prefer "it" (for some value of...)
to be done in the LLD. ;-)
Jeff
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