Hello, On 12/01/2010 06:53 AM, Lin Mac wrote: > While using multiplier with CONFIG_SATA_PMP enabled, or using disks directly > without CONFIG_SATA_PMP have no issue. > > It is because sata_srst_pmp always return SATA_PMP_CTRL_PORT(15), > which casued ahci_do_softreset with pmp 15, which is not needed for > disks connected directly. SRST w/ PMP==15 is the standard defined way to probe devices for PMP capable controllers. > With SPMH3726-P rev:2.1.2, ata_dev_classify would report ATA_DEV_UNKNOWN on > ahci_hardreset. While with a Segate Barracuda 1TB SATA HD, it is ATA_DEV_ATA. > Therefore, the pmp returned by sata_srst_pmp should depends on the class > reported by ahci_hardreset. IIRC, PMP should return the signature of the first device after hardreset. At any rate, the standard sanctioned way to probe is SRST w/ PMP==15. > This patch does 2 things: > 1. ata_eh_reset calls ata_do_reset upon SRST without clearing classes, to be > used by sata_srst_pmp to decide pmp. > 2. sata_srst_pmp returns SATA_PMP_CTRL_PORT only when class is ATA_DEV_PMP or > ATA_DEV_UNKNOWN So, no, this isn't acceptable. You're making the behavior deviate from the standard for all controllers and devices to work around a faulty, rather obscure controller. If you want to work around, please implement a workaround which is specific to the controller in question. Thanks. -- tejun -- 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
