| Message ID | 1477945112-25659-4-git-send-email-linux@rainbow-software.org (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
On Mon, 31 Oct 2016, Ondrej Zary wrote: > Write and read back MODE_REG to check if the chip is really there > before doing more initialization. > > This prevents hang when incorrect I/O address was specified by user (in > the most common case where no device is present there so all reads > result in 0xff). > > Signed-off-by: Ondrej Zary <linux@rainbow-software.org> > --- > drivers/scsi/g_NCR5380.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/scsi/g_NCR5380.c b/drivers/scsi/g_NCR5380.c > index 0d1f6ad..e713dba 100644 > --- a/drivers/scsi/g_NCR5380.c > +++ b/drivers/scsi/g_NCR5380.c > @@ -322,6 +322,13 @@ static int generic_NCR5380_init_one(struct scsi_host_template *tpnt, > } > } > > + /* check if the chip is really there */ > + NCR5380_write(MODE_REG, 0); > + if (NCR5380_read(MODE_REG) != 0) { Wouldn't it be more accurate to write, /* Check for some kind of device. A vacant slot reads 0xff. */ ? > + ret = -ENODEV; > + goto out_unregister; > + } > + > ret = NCR5380_init(instance, flags | FLAG_LATE_DMA_SETUP); > if (ret) > goto out_unregister; >
diff --git a/drivers/scsi/g_NCR5380.c b/drivers/scsi/g_NCR5380.c index 0d1f6ad..e713dba 100644 --- a/drivers/scsi/g_NCR5380.c +++ b/drivers/scsi/g_NCR5380.c @@ -322,6 +322,13 @@ static int generic_NCR5380_init_one(struct scsi_host_template *tpnt, } } + /* check if the chip is really there */ + NCR5380_write(MODE_REG, 0); + if (NCR5380_read(MODE_REG) != 0) { + ret = -ENODEV; + goto out_unregister; + } + ret = NCR5380_init(instance, flags | FLAG_LATE_DMA_SETUP); if (ret) goto out_unregister;
Write and read back MODE_REG to check if the chip is really there before doing more initialization. This prevents hang when incorrect I/O address was specified by user (in the most common case where no device is present there so all reads result in 0xff). Signed-off-by: Ondrej Zary <linux@rainbow-software.org> --- drivers/scsi/g_NCR5380.c | 7 +++++++ 1 file changed, 7 insertions(+)