Ar Maw, 2006-08-01 am 02:03 +0900, ysgrifennodd Tejun Heo: > Alan, the reason why the second port disappeared is a bug in > init_legacy_mode(). probe_ent->n_ports is fxied to 1 and port_no gets > incremented while initializing the second port ending up initializing > part of the third port. Ouch yes. > Another problem is that probe_ent/ap->hard_port_no are meaningless. > hard_port_no is used to get port_no right on legacy cases where index of > host_set->ports[] doesn't match the actual port_no. When there is only > one host_set, port_no should always equal hard_port_no. For legacy > hosts, the original code ended up assigning the wrong hard_port_no's. Agreed. I looked at that but it seemed that it isn't true that you can assume port_no == hard_port_no because you may have a device which has the primary port disabled and the secondary port set legacy. This also sort of comes up in mixed devices but we don't handle them and I think it comes out correctly once we do the pure legacy case right. > I killed hard_port_no by s/ap->hard_port_no/ap->port_no/g without > actually reviewing the usages (man, those are a LOT). If all pata > drivers always relied on ap->hard_port_no representing the actual port > index in the controller, there shouldn't be a problem. But, just in > case, please review the change. Think about the following execution sequence ati_pci_init_one primary port already stolen by drivers/ide secondary port free legacy_mode = ATA_PORT_SECONDARY ata_pci_init_legacy_port port_num = 0 hard_port_num = 1 *kerunnccchhhhhh* > If this fixes Magallon's problem and you agree with the fix, I'll break > it down to two patches and submit'em to you with proper heading and all. I agree with the theory and the diagnosis. I'm a bit worried about hard_port_no however and I don't think that bit is safe in the secondary only corner case. Registering both always and disabling one works for me as a cleanup. If you do that then I'll audit all the drivers use of ->port_no against the patches. Alan - : 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
