Re: [PATCH] scsi: gvp11: add module parameter for DMA transfer bit mask

Arnd Bergmann
2023-08-29T22:06:35Z

On Tue, Aug 29, 2023, at 17:45, Michael Schmitz wrote:
> SCSI boards on Amiga. There now is no way to set a non-default
> DMA mask on these boards.

It might help to mention here in which cases the default mask
is actually wrong.

> +module_param(gvp11_xfer_mask, int, 0444);
> +MODULE_PARM_DESC(gvp11_xfer_mask, "DMA mask (0xff000000 == 24 bit DMA)");
> +

I think the comment is the wrong way round, it should be
0x00ffffff in this case, which also matches the default
mask for ZORRO_PROD_GVP_SERIES_II, in the match table:

static struct zorro_device_id gvp11_zorro_tbl[] = {
{ ZORRO_PROD_GVP_COMBO_030_R3_SCSI, ~0x00ffffff },
{ ZORRO_PROD_GVP_SERIES_II, ~0x00ffffff },
{ ZORRO_PROD_GVP_GFORCE_030_SCSI, ~0x01ffffff },
{ ZORRO_PROD_GVP_A530_SCSI, ~0x01ffffff },
{ ZORRO_PROD_GVP_COMBO_030_R4_SCSI, ~0x01ffffff },
{ ZORRO_PROD_GVP_A1291, ~0x07ffffff },
{ ZORRO_PROD_GVP_GFORCE_040_SCSI_1, ~0x07ffffff },
{ 0 }
};

Arnd