On Sun, 14 Oct 2018, Geert Uytterhoeven wrote:
Fixes: 3109e5ae0311
Fixes: 3109e5ae0311 ("scsi: zorro_esp: New driver for Amiga Zorro
NCR53C9x boards")
OK.
$ git help fixes
'fixes' is aliased to 'show --format='Fixes: %h ("%s")' -s'
BTW, if you use vim, add
noremap ;gs "zyiw:exe "new \| setlocal buftype=nofile
bufhidden=hide noswapfile syntax=git \| 0r ! git show ".@z."" \|
:0<CR><CR>
to .vimrc, and type ";gs" when the cursor is positioned on a commit ID.
Thanks.
Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
Cc: Michael Schmitz <schmitzmic@xxxxxxxxx>
Tested-by: Michael Schmitz <schmitzmic@xxxxxxxxx>
--- a/drivers/scsi/zorro_esp.c
+++ b/drivers/scsi/zorro_esp.c
@@ -245,7 +245,7 @@ static int fastlane_esp_irq_pending(struct esp *esp)
static u32 zorro_esp_dma_length_limit(struct esp *esp, u32 dma_addr,
u32 dma_len)
{
- return dma_len > 0xFFFFFF ? 0xFFFFFF : dma_len;
+ return dma_len > 0xFFFF ? 0xFFFF : dma_len;
}
static void zorro_esp_reset_dma(struct esp *esp)
@@ -484,7 +484,6 @@ static void zorro_esp_send_blz1230_dma_cmd(struct esp *esp, u32 addr,
scsi_esp_cmd(esp, ESP_CMD_DMA);
zorro_esp_write8(esp, (esp_count >> 0) & 0xff, ESP_TCLOW);
zorro_esp_write8(esp, (esp_count >> 8) & 0xff, ESP_TCMED);
- zorro_esp_write8(esp, (esp_count >> 16) & 0xff, ESP_TCHI);
Since all these sub-drivers seem to support 24-bit transfers, perhaps this is
something to be fixed in the esp_scsi core?
I don't think there is anything to fix in the esp_scsi core. The fact that
no-one saw the error indicates that large transfers don't occur in
practice.
If you said there is an opportunity for an enhancement, I could agree,
assuming that you also found a way to produce large IO requests. But I
doubt that such an enhancement would make a measurable improvement.
Even if the benefit was measurable, the fix under review would still be
needed for stable kernels.
BTW, Michael and I already discussed all this (it probably should have
happened on the linux-m68k list).
Please see,
$ grep -lr ESP_CONFIG2_FENAB drivers/scsi/
drivers/scsi/am53c974.c
drivers/scsi/esp_scsi.c
drivers/scsi/esp_scsi.h
The authors of am53c974.c obviously decided it wasn't wise to make this
feature mandatory (which suggests that perhaps it shouldn't go into common
code).
The comments in esp_scsi.c say that ESP_CONFIG2_FENAB has undesirable
consequences. There is information in the datasheets on this point but I
didn't follow it up because I don't see a performance issue.
--
