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

[Sergei Shtylyov <sshtylyov@ru.mvista.com>]

Bartlomiej Zolnierkiewicz wrote:

> Add ->read_sff_dma_status method for reading DMA Status register
> and use it instead of ->INB.

> While at it:

> * Use inb() directly in ns87415.c::ns87415_dma_end().

> There should be no functional changes caused by this patch.

> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

> Index: b/drivers/ide/ide-iops.c
> ===================================================================
> --- a/drivers/ide/ide-iops.c
> +++ b/drivers/ide/ide-iops.c
> @@ -103,6 +103,14 @@ void SELECT_MASK(ide_drive_t *drive, int
>  		port_ops->maskproc(drive, mask);
>  }
>  
> +static u8 ide_read_sff_dma_status(ide_hwif_t *hwif)
> +{
> +	if (hwif->host_flags & IDE_HFLAG_MMIO)
> +		return readb((void __iomem *)hwif->dma_status);
> +	else
> +		return inb(hwif->dma_status);
> +}
> +

    It's probably too late to object now (and I've been busy before) but I 
don't understand how reading DMA status ended up here ISO ide-dma.c...

>  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.

MBR, Sergei