Hello, all. This is the third take of libata-pmp-prep patchset. This patchset contains 5 patches and implements various stuff needed for PMP. Changes from the last take[L] are. * rebased * sata_link_hardreset() separation is done earlier by vt8251-ahci patchset and thus dropped from this patchset. This patchset is against upstream (da54f5fe54c7d75e2db7d17961fb36a8c28a8501) + [1] hp-poll patchset, take #5 + [2] vt8251-ahci patchset, take #2 + [3] libata-link patchset, take #3 Git tree can be accessed at http://htj.dyndns.org/git/?p=libata-tj.git;a=shortlog;h=pmp-prep git://htj.dyndns.org/libata-tj pmp-prep Jeff, I couldn't merge ->qc_defer() into ->qc_prep() or ->qc_issue(). The problem is that ->qc_prep() is done after sg mapping is done which is a bit costly to throw away if the qc has to be deferred. ->qc_defer() is called right after qc is allocated and translated but before any resource for qc execution is acuquired. Another way would be to let ->qc_issue() determine whether deferring is needed and cache prepared qc while deferred. This has the following problems. * qc and related resources are held by deferred command. Currently, qc directly maps to hardware command slots and w/ PMP this can get messy. * Separate requeueing/restarting mechanism must be implemented. ATM, libata depends on SCSI for retrying deferred commands with reasonable fairness. To hold prepared qc, libata needs to implement its own mechanism and I don't think the added benefits justify the complexity. So, I think it's better to keep ->qc_defer(). Thanks. -- tejun [L] http://article.gmane.org/gmane.linux.ide/11928 [1] http://article.gmane.org/gmane.linux.ide/13467 [2] http://article.gmane.org/gmane.linux.ide/13471 [3] http://article.gmane.org/gmane.linux.ide/13478 - 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
