From: Jeff Garzik Date: Tue, 4 Oct 2005 01:36:41 +0000 (-0400) Subject: [libata] improve device scan even more X-Git-Tag: v2.6.15-rc1~736^2~12^2 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3f19ee8cb3a1003cb5183696bc55934f5865f868;p=linux-2.6 [libata] improve device scan even more Since our max_lun is unconditionally set to 1, we might as well hardcode a LUN 0 probe, rather than a wildcard LUN scan. The ide-scsi driver sets max_lun to a value greater than under certain conditions: if ((drive->id->last_lun & 0x7) != 7) host->max_lun = (drive->id->last_lun & 0x7) + 1; else host->max_lun = 1; last_lun is Word 126 of IDENTIFY PACKET DEVICE, marked as obsolete and undocumented in non-ancient specs. We'll leave it out for now. Should the need arise to support multi-LUN ATAPI devices, we'll probably want to add the above code. Finally, there have been reports of REPORT LUNS commands locking up ATAPI drives. Eliminating the wildcard LUN scan could help reduce the trouble from problematic drives. --- diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c index 4fc0134d42..8295a656e5 100644 --- a/drivers/scsi/libata-scsi.c +++ b/drivers/scsi/libata-scsi.c @@ -1680,13 +1680,17 @@ void ata_scsi_simulate(u16 *id, void ata_scsi_scan_host(struct ata_port *ap) { + struct ata_device *dev; unsigned int i; if (ap->flags & ATA_FLAG_PORT_DISABLED) return; - for (i = 0; i < ATA_MAX_DEVICES; i++) - if (ata_dev_present(&ap->device[i])) - scsi_scan_target(&ap->host->shost_gendev, 0, i, ~0, 0); + for (i = 0; i < ATA_MAX_DEVICES; i++) { + dev = &ap->device[i]; + + if (ata_dev_present(dev)) + scsi_scan_target(&ap->host->shost_gendev, 0, i, 0, 0); + } }