On Thu, Sep 13, 2012 at 4:07 AM, Gwendal Grignou <gwendal@xxxxxxxxxx> wrote: > [-Lin, +Lin] CC Aaron@Intel > > On Wed, Sep 12, 2012 at 1:02 PM, Gwendal Grignou <gwendal@xxxxxxxxxx> wrote: >> Lin, >> >> Commit 9a6d6a2ddabbd32c07f6a38b659e5f3db319fa5a introduces a change >> in sysfs directory for ata controller: >> >> Before: >> /sys/devices/pci0000:00/0000:00:1f.2 (ahci controller) >> |-- ata1 (ata port) >> |-- host0 (scsi host) >> |-- target0:0:0 (scsi target) >> |-- 0:0:0:0 (disk) >> >> After: >> /sys/devices/pci0000:00/0000:00:1f.2 (ahci controller) >> |-- ata1 (ata port) >> |-- host0 (scsi host) >> |-- target0:0:0 (scsi target) >> |-- 0:0:0:0 (disk) >> >> The problem is an ata controller, managed by libata, is still >> considered by the kernel as a SCSI controller: diverging even more >> from other SCSI controller sysfs layout is not a good idea. >> When I wrote libata-transport.c, my plan was to be consistent with SAS >> objects: for instance, for a SAS controller with a simple SAS topology >> we have: >> >> >> /sys/bus/pci/devices/0000\:0c\:00.0/ >> |-- host7/ >> |-- phy-7:0 >> |-- phy-7:1 >> .. >> |-- phy-7:7 >> |-- port-7:0 >> |-- end_device-7\:0 >> |-- target7:0:0/ >> |-- 7:0:0:0 >> |-- port-7:1 >> .. >> >> Similarly, I wanted to represent an ata_port [equivalent to SAS phy] >> and ata_link [equivalent to SAS port] under scsi_host hostX object, >> but as far as i remember, when I wrote the code that was not possible, >> I could not find a clean way to share object references between libata >> and scsi layer. That's why ata_port object was sitting alongside to >> the scsi_host object. I have to see if it is possible now. >> >> In the meantime, what would be the impact to revert that commit? >> Do you think melting libata sysfs object into scsi sysfs objects would >> work with your changes related to pm? The SATA disk runtime pm and ZPODD(Zero Power ODD) relies on the new sysfs directory I introduced in commit 9a6d6a2. Could you show me what's the sysfs directory structure after libata sysfs object melted into scsi sysfs objects? Thanks, Lin Ming >> >> Thanks, >> >> Gwendal. -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
