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

[Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>]

On Sunday 07 September 2008, Sergei Shtylyov wrote:
> 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...

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

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

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

Thanks,
Bart