Re: AW: [PATCH] mcp251x: mcp2515 stops receiving

["Alexander Shiyan" <shc_work@mail.ru>]

Mon, 12 May 2014 17:34:14 +0000 от "Rost, Martin" <Martin.Rost@tonfunk.de>:
> Hello Alexander,
> 
> > I absolutely don't like the patch. This is not a solution to the problem but
> > ways to circumvent it.
> 
> True that. I whish I had a better solution.
> 
> > I would recommend to make a temporary parameter for sysfs, then when a
> > problem occurs, you could take a snapshot from all registers (including an
> > interrupt status register) and understand what the problem is.
> 
> I've never done that. Any hints on how to start on this?

I can not guarantee the accuracy, but something like this:

static ssize_t dbg_show(struct device *dev, struct device_attribute *attr, char *buf)
{
  unsigned i;
  ssize_t ret = 0;

  for (i = 0; i < NUM_SPI_REGS; i++)
    ret += sprintf(buf, "[0x%02x] = 0x%02x\n", i, SPI_REG[i]);

  return ret;
}

static DEVICE_ATTR_RO(dbg);

static struct attribute *dbg_sysfs_attrs[] = {
  &dev_attr_dbg.attr,
};

static const struct attribute_group dbg_sysfs_group = {
  .attrs = dbg_sysfs_attrs,
};

...
sysfs_create_group(&client->dev.kobj, &dbg_sysfs_group);

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