Re: [PATCH v2] scsi: Remember if a device is an ATA device

[Bart Van Assche <bvanassche@acm.org>]

On 6/11/25 2:34 AM, Damien Le Moal wrote:
> scsi_add_lun() tests the device vendor string of SCSI devices to detect
> if a SCSI device is in fact an ATA device, in order to correctly handle
> SATL power management. The function scsi_cdl_enable() also requires
> knowing if a SCSI device is an ATA device to control the state of the
> device CDL feature but this function does that by testing for the
> presence of the VPD page 89h (ATA INFORMATION page).
> sd_read_write_same() also has a similar test.
> 
> Simplify these different methods by adding the is_ata field to struct
> scsi_device to remember that a SCSI device is in fact an ATA one based
> on the device vendor name test. This filed can also allow low level
> SCSI host adapter drivers to take special actions for ATA devices
> (e.g. to better handle ATA NCQ errors).
> 
> With this, simplify scsi_cdl_enable() and sd_read_write_same().
Hi Damien,

There is only one "if (is_ata)" check in the SCSI core as far as I can
see. Can it be avoided that ATA code leaks into the SCSI core by
introducing a new function pointer, e.g. in struct Scsi_Host, and by
calling that new function pointer if it has been set from
scsi_cdl_enable()?

Thanks,

Bart.