Re: [PATCH v2 74/71] ncr5380: Enable PDMA for NCR53C400A

Ondrej Zary
2015-12-09T13:39:06Z

On Tuesday 08 December 2015 03:05:11 Finn Thain wrote:
>
> On Sun, 6 Dec 2015, Ondrej Zary wrote:
>
> > Add I/O register mapping for NCR53C400A and enable PDMA mode to
> > improve performance and fix non-working IRQ.
> >
> > Tested with HP C2502 (and user-space enabler).
> >
> > Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
> > ---
> > drivers/scsi/g_NCR5380.c | 14 +++++++++++---
> > 1 file changed, 11 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/scsi/g_NCR5380.c b/drivers/scsi/g_NCR5380.c
> > index 86740fd..099fdac 100644
> > --- a/drivers/scsi/g_NCR5380.c
> > +++ b/drivers/scsi/g_NCR5380.c
> > @@ -324,7 +324,7 @@ static int __init generic_NCR5380_detect(struct scsi_host_template *tpnt)
> > #endif
> > break;
> > case BOARD_NCR53C400A:
> > - flags = FLAG_NO_PSEUDO_DMA;
> > + flags = FLAG_NO_DMA_FIXUP;
> > ports = ncr_53c400a_ports;
> > break;
> > case BOARD_DTC3181E:
> > @@ -406,11 +406,18 @@ static int __init generic_NCR5380_detect(struct scsi_host_template *tpnt)
> > * On NCR53C400 boards, NCR5380 registers are mapped 8 past
> > * the base address.
> > */
> > - if (overrides[current_override].board == BOARD_NCR53C400) {
> > + switch (overrides[current_override].board) {
> > + case BOARD_NCR53C400:
> > instance->io_port += 8;
> > hostdata->c400_ctl_status = 0;
> > hostdata->c400_blk_cnt = 1;
> > hostdata->c400_host_buf = 4;
> > + break;
> > + case BOARD_NCR53C400A:
> > + hostdata->c400_ctl_status = 9;
> > + hostdata->c400_blk_cnt = 10;
> > + hostdata->c400_host_buf = 8;
> > + break;
> > }
> > #else
> > instance->base = overrides[current_override].NCR5380_map_name;
>
>
> For SCSI_G_NCR5380_MEM and BOARD_NCR53C400A (or BOARD_DTC3181E), you have
> not assigned c400_ctl_status, c400_blk_cnt and c400_host_buf. Perhaps we
> should throw an error, something like this?
>
> hostdata->iomem = iomem;
> - if (overrides[current_override].board == BOARD_NCR53C400) {
> + switch (overrides[current_override].board) {
> + case BOARD_NCR53C400:
> hostdata->c400_ctl_status = 0x100;
> hostdata->c400_blk_cnt = 0x101;
> hostdata->c400_host_buf = 0x104;
> + break;
> + case BOARD_NCR53C400A:
> + pr_err(DRV_MODULE_NAME ": unknown register offsets\n");
> + goto out_unregister;
> }
> #endif

We don't need to fail, just disable PDMA by setting:
flags = FLAG_NO_PSEUDO_DMA;

And BTW. this:
if (overrides[current_override].board == BOARD_NCR53C400 ||
overrides[current_override].board == BOARD_NCR53C400A)
NCR5380_write(hostdata->c400_ctl_status, CSR_BASE);

should then be, solving the problem of growing if condition:
if (!(flags & FLAG_NO_PSEUDO_DMA))
NCR5380_write(hostdata->c400_ctl_status, CSR_BASE);

--
Ondrej Zary