Re: [PATCH 01/18] ide: add ->read_sff_dma_status method

[Sergei Shtylyov]

Hello.

Bartlomiej Zolnierkiewicz wrote:

> > > > > static void ide_tf_load(ide_drive_t *drive, ide_task_t *task)
> > > > > {
> > > > > 	ide_hwif_t *hwif = drive->hwif;
> > > > > @@ -323,6 +331,8 @@ static void ata_output_data(ide_drive_t 
> > > > >
> > > > > void default_hwif_transport(ide_hwif_t *hwif)
> > > > > {
> > > > > +	hwif->read_sff_dma_status = ide_read_sff_dma_status;
> > > > > +
> > > > > 	hwif->tf_load	  = ide_tf_load;
> > > > > 	hwif->tf_read	  = ide_tf_read;
> > > > >           
> > > >    I also didn't understand the motivation behind putting this method 
> > > > together with the transport operations... IMO, DMA programming interface 
> > > > hardly has anything to do with transporting the data over IDE bus.
> > > >         
> > > The motivation was that hwif->dma_ops is not available yet when
> > > ->read_sff_dma_status is used in ide_pci_check_simplex().
> > >       
> > > However I agree that it should somehow find its way into ->dma_ops
> > > (as usual patches are stongly preffered :).
> > >       
> >     Unless I'm missing something changing the place where hwif->dma_ops is 
> > initialized to sff_dma_ops (along the lines it was changed for hwif->dma_base) 
> > seems pretty trivial, so I wonder why you didn't do it in the same patch...
> >     

  Ah, I forgot for a moment that there were two patches and it would 
have make no sense to do that in the patch that factored out 
ide_pci_check_simplex()... And then tre was a patch introducing 'struct 
ide_tp_ops' which incorporated the read_sff_dma_status() method.

> Indeed, it should be trivial now, one just needs to be careful to:
>
> * move 'if (d->dma_ops) ...' from ide_init_port() into
>   ->init_dma/ide_hwif_setup_dma()
>
> * unset ->dma_ops on ->init_dma/ide_hwif_setup_dma() failures
>   

  Sure.

> I guess I overlooked it ATM of making the patch (or the code evolved
> greatly in the meantime)...
>   

  I think I understand now: it's sticking read_sff_dma_status() method 
into 'struct ide_tp_ops' that was a wrong move that's worth undoing (by 
putting it where it really belongs).

> [ It is really time consuming and difficult to recall the every small
>   detail of every patch after few months (the patch was posted 10 weeks
>   

  Heh, as if it wasn't time consuming to untange that after a few 
months (when I'm suposed to spend time elsewhere :-)...

>   ago and merged 6 weeks ago)...  The most efficient way of handling
>   such issues upon discovery is with sending patches... ]
>   

   Sigh, I'll see what I can do in my currently very limieted time...

> Thanks,
> Bart
>   

MBR, Sergei


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