libata: improve SCSI scan failure handling

SCSI scan may fail due to memory allocation failure even if EH is not
in progress.  Due to use of GFP_ATOMIC in SCSI scan path, allocation
failure isn't too rare especially while probing multiple devices at
once which is the case when a bunch of devices are connected to PMP.

This patch moves SCSI scan failure detetion logic from
ata_scsi_hotplug() to ata_scsi_scan_host() and implement synchronous
scan behavior.  The synchronous path sleeps briefly and repeats SCSI
scan if some devices aren't attached properly.  It contains robust
retry loop to minimize the chance of device misdetection during boot
and falls back to async retry if everything fails.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
Tejun Heo
2007-07-16 14:29:40 +09:00
committed by Jeff Garzik
parent f1545154a5
commit 1ae463171c
3 changed files with 49 additions and 18 deletions

View File

@@ -112,7 +112,7 @@ static inline int ata_acpi_on_devcfg(struct ata_device *adev) { return 0; }
/* libata-scsi.c */
extern int ata_scsi_add_hosts(struct ata_host *host,
struct scsi_host_template *sht);
extern void ata_scsi_scan_host(struct ata_port *ap);
extern void ata_scsi_scan_host(struct ata_port *ap, int sync);
extern int ata_scsi_offline_dev(struct ata_device *dev);
extern void ata_scsi_hotplug(struct work_struct *work);
extern unsigned int ata_scsiop_inq_std(struct ata_scsi_args *args, u8 *rbuf,