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    SubjectRe: [RFC PATCH 76/71] ncr5380: Enable PDMA for DTC chips
    Hi Finn, Ondrej,

    One small question:

    On Fri, Dec 4, 2015 at 10:03 AM, Ondrej Zary <linux@rainbow-software.org> wrote:
    > Add I/O register mapping for DTC chips and enable PDMA mode.
    >
    > These chips have 16-bit wide HOST BUFFER register (counter register at
    > offset 0x0d increments by 2 on each HOST BUFFER read).
    >
    > Large PIO transfers crash at least the DTCT-436P chip (all reads result
    > in 0xFF) so this patch actually makes it work.
    >
    > The chip also crashes when we bang the C400 host status register too
    > heavily after PDMA write - a small udelay is needed.
    >
    > Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
    > ---
    > # hdparm -t --direct /dev/sdb
    >
    > /dev/sdb:
    > Timing O_DIRECT disk reads: 4 MB in 3.78 seconds = 1.06 MB/sec
    >
    >
    > drivers/scsi/NCR5380.h | 1 +
    > drivers/scsi/g_NCR5380.c | 47 +++++++++++++++++++++++-----------------------
    > 2 files changed, 25 insertions(+), 23 deletions(-)
    >
    > diff --git a/drivers/scsi/g_NCR5380.c b/drivers/scsi/g_NCR5380.c
    > index fae4332..04f6c29 100644
    > --- a/drivers/scsi/g_NCR5380.c
    > +++ b/drivers/scsi/g_NCR5380.c
    > @@ -415,7 +415,8 @@ static int __init generic_NCR5380_detect(struct scsi_host_template *tpnt)
    > hostdata->c400_blk_cnt = 1;
    > hostdata->c400_host_buf = 4;
    > }
    > - if (overrides[current_override].board == BOARD_NCR53C400A) {
    > + if (overrides[current_override].board == BOARD_NCR53C400A ||
    > + overrides[current_override].board == BOARD_DTC3181E) {

    These if statements are starting to get a bit long, would it make
    sense to replace them with a flag or equivalent?

    Thanks,

    --
    Julian Calaby

    Email: julian.calaby@gmail.com
    Profile: http://www.google.com/profiles/julian.calaby/


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