On 20/04/16 18:24, Hartley Sweeten wrote:
On Wednesday, April 20, 2016 2:44 AM, Ian Abbott wrote:
On 19/04/16 17:41, Hartley Sweeten wrote:
[snip]
How do you feel about removing the "unknown" interrupt checks?
If they are removed the CHSR_* defines in mite.h can be moved to the
mite driver and not be needlessly exposed.
I've seen occasional (but unresolved) threads on the COMEDI mailing
lists from people getting the "unknown mite interrupt" messages, so it's
probably best to leave them in for now.
For example, this one:
https://groups.google.com/d/topic/comedi_list/dDH4BxqLhSk/discussion
[snip]
I found a titled "MITE RLPM: MITE PCI/PXI Interface and DMA Controller".
It's looks to be pretty recent but it's not very complete. The header of the
document states: "MITE RLPM rough draft v0.1 4/20/2016 (C) National
Instruments"
From that document.
The MERR bits indicate a "Memory Transfer Error":
00 - No Error
01 - Bus Error
10 - Retry Limit Exceeded
11 - Other Transfer Error (Parity for MXI)
In this case the MRERR is indicating a retry limit exceeded
Currently the mite driver sets all the "retry limits" to 64. This results in
a CR_RL() value of 7 which is the maximum value that can be used by
those bits. I should just remove the mite_retry_limit() helper and just
use CR_RL(7) instead.
[snip]
But, it looks like a "transfer error" can be detected by just checking the
XFERR bit. This bit indicates that the transfer was terminated by a LERR,
MERR, or DERR. This test could be moved into mite_ack_linkc() as:
-unsigned int mite_ack_linkc(struct mite_channel *mite_chan)
+unsigned int mite_ack_linkc(struct mite_channel *mite_chan,
+ struct comedi_subdevice *s)
{
struct mite_struct *mite = mite_chan->mite;
unsigned int status;
status = mite_get_status(mite_chan);
if (status & CHSR_LINKC)
writel(CHOR_CLRLC,
mite->mite_io_addr + MITE_CHOR(mite_chan->channel));
+ if (status & CHSR_XFERR) {
+ dev_err(s->device->class_dev,
+ "mite transfer error %08x\n", status);
+ s->async->events |= COMEDI_CB_ERROR;
+ }
+
return status;
}
EXPORT_SYMBOL_GPL(mite_ack_linkc);
Then the CHSR defines can all be moved into mite.c and not get exposed.
Sound reasonable?
Seems reasonable enough. Thanks for investigating!
--
-=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@xxxxxxxxx> )=-
-=( Web: http://www.mev.co.uk/ )=-
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