Messages in this thread | | | Date | Mon, 28 May 2001 17:09:20 -0700 (PDT) | From | Andre Hedrick <> | Subject | Re: [patch]: ide dma timeout retry in pio |
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On Tue, 29 May 2001, Jens Axboe wrote:
> This is bull shit. If IDE didn't muck around with the request so much in > the first place, the info could always be trusted. Even so, we have the > hard_* numbers to go by. So this argument does not hold.
Maybe if you looked at the new code model as a whole you would see that the request-forking is gone. The object is to preserve a copy of the io instructions out to the registers to not have to repeat the do_request call unless it is a do or die thing. Also it is good to carry a copy of the local request even if it is never used. Also are you resetting the pointer (back to the geginning) on rq->buffer on the retry?
You first flush the DMA engine and issue a device soft reset not using the current drive reset, is presevers the hwgroup->busy state and allows the request to be retried without reinserting.
> > As I recall, there is a way to reinsert the faulted request, but that > > Again, look at the patch. The request is never off the list, so there is > never a reason to reinsert. hwgroup->busy is cleared (and, again for > good measure, hwgroup->rq), so ide_do_request/start_request will get the > same request that we just handled.
I will have to poke in a few flags to verify this but if you say so.
> > means the request_struct needs fault counter. If it is truly a DMA error > > ->errors, it's already there.
Wrong location to poke and by that time it requires a full retry. The new code would have had the task structs filled with the error.
> > because of re-seeks then the timeout value for that request must be > > expanded. > > Yep
In some cases yes, but it would be better if I had a standard counter that meant something. Also changing the jiffie counter in ide_delay_50ms to a mdelay may have done more harm than good.
Andre Hedrick Linux ATA Development ASL Kernel Development ----------------------------------------------------------------------------- ASL, Inc. Toll free: 1-877-ASL-3535 1757 Houret Court Fax: 1-408-941-2071 Milpitas, CA 95035 Web: www.aslab.com
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