Hi Michael,
On Wed, Aug 30, 2023 at 12:26 AM Michael Schmitz <schmitzmic@xxxxxxxxx> wrote:
On 30/08/23 10:05, Arnd Bergmann wrote:
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.
All I have is:
Probably it's needed on A2000 with an accelerator card and GVP II SCSI,
to prevent DMA to RAM banks that do not support fast DMA cycles.
from Geert's reply. I can add that. It just did sound a shade
speculative...
Apparently gvp11_setup() became unused in 2.3.13pre2 (in 1999), when all
*_setup() functions were removed from init/main.c, and some of them were
reimplemented using __setup() in the driver sources where they belonged.
+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 }
};
The default masks above were added (in some other form) in 2.1.91pre1
(in 1998). Before, people had to use gvp11_setup() to do that.
So I think it is safe to assume there is no longer a need to configure
this manually.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
