Hi, Please consider this patch as Ack-by: Chaitra P B <chaitra.basappa@xxxxxxxxxxxx> Thanks, Chaitra -----Original Message----- From: Sathya Prakash [mailto:sathya.prakash@xxxxxxxxxxxx] Sent: Saturday, April 02, 2016 1:45 AM To: emilne@xxxxxxxxxx; Joe Lawrence Cc: linux-scsi@xxxxxxxxxxxxxxx; Chaitra Basappa; Suganath Prabu Subramani; Calvin Owens Subject: RE: [PATCH] mpt3sas - remove unused fw_event_work delayed_work We will look into this early next week and provide a detailed response. On the first look this is ACK from Broadcom, will reconfirm. -----Original Message----- From: Ewan D. Milne [mailto:emilne@xxxxxxxxxx] Sent: Friday, April 01, 2016 2:04 PM To: Joe Lawrence Cc: linux-scsi@xxxxxxxxxxxxxxx; Sathya Prakash; Chaitra P B; Suganath Prabu Subramani; Calvin Owens Subject: Re: [PATCH] mpt3sas - remove unused fw_event_work delayed_work On Fri, 2016-04-01 at 15:13 -0400, Joe Lawrence wrote: > On 04/01/2016 02:51 PM, Ewan D. Milne wrote: > > On Fri, 2016-04-01 at 13:56 -0400, Joe Lawrence wrote: > >> @@ -2804,12 +2803,12 @@ _scsih_fw_event_cleanup_queue(struct > >> MPT3SAS_ADAPTER *ioc) > >> /* > >> * Wait on the fw_event to complete. If this returns 1, then > >> * the event was never executed, and we need a put for the > >> - * reference the delayed_work had on the fw_event. > >> + * reference the work had on the fw_event. > >> * > >> * If it did execute, we wait for it to finish, and the put will > >> * happen from _firmware_event_work() > >> */ > >> - if (cancel_delayed_work_sync(&fw_event->delayed_work)) > >> + if (cancel_work_sync(&fw_event->work)) > >> fw_event_work_put(fw_event); > >> > >> fw_event_work_put(fw_event); > > > > Hmm... Fixes: 146b16c8 (mpt3sas: Refcount fw_events and fix unsafe > > list usage) > > This could technically go back to f92363d12359 (mpt3sas: add new > driver supporting 12GB SAS) ... but will probably only apply cleanly > to _scsih_fw_event_cleanup_queue after 146b16c8 (mpt3sas: Refcount > fw_events and fix unsafe list usage), so you're right. > > > Since mpt3sas uses ->work instead of _delayed_work this would seem > > to be correct, however the deprecated mpt2sas driver had a commit > > that changed the firmware event work mechanism to use ->delayed_work > > instead of ->work: > > > > commit f1c35e6aea579d5bdb6dc02dfa99c67c7c3b3f67 > > Author: Kashyap, Desai <kashyap.desai@xxxxxxx> > > Date: Tue Mar 9 16:31:43 2010 +0530 > > Okay, so this is pre-mpt3sas split. > > > [SCSI] mpt2sas: RESCAN Barrier work is added in case of HBA reset. > > > > Add the cancel_pending_work flag from the fw_event_work > > structure, and then to > > set the flag during host reset, check the flag later from work > > threads > > context and if cancel_pending_work_flag is set ingore those events. > > More unused mpt2 vestiges in the mpt3 version? > > % cd drivers/scsi/mpt3sas/ > % grep 'cancel_pending_work' *.{c,h} > mpt3sas_scsih.c: * @cancel_pending_work: flag set during reset handling > mpt3sas_scsih.c: u8 cancel_pending_work; > > > Now Rescan after host reset is changed. > > Added special task MPT2SAS_RESCAN_AFTER_HOST_RESET. This task > > will be queued > > at the time of HBA reset. this task is treated as barrier. All > > work after > > MPT2SAS_RESCAN_AFTER_HOST_RESET will be treated as new work and > > will be > > server by callback handle. If host_recovery is going on while > > running RESCAN > > task, it will wait for shos_recovery_done completion which will > > be called > > from HBA reset DONE context. > > FWIW, I don't see anything like this in today's mpt3sas driver. Well, that's the question. Is there some functionality missing? Were the changes abandoned/replaced? mpt2sas used delayed_work for something else, so maybe that's why the firmware event changes initially used it (albeit with a 0 delay) but it's hard to know... cancel_delayed_work() will call del_timer() on delayed_work->timer, but it looks like kzalloc is used to allocate the fw_event_work objects so perhaps nothing bad will happen. I was wondering, though, because I have seen dumps of hung systems with requests that should have timed out but are not on any timer list. -Ewan > > Regards, > > -- Joe -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
