On 01/02/07 09:15, Duncan Sands wrote:
> On Thursday 1 February 2007 00:39:14 you wrote:
>> On Tue, 30 Jan 2007 21:30:29 +0000
>> Simon Arlott <[EMAIL PROTECTED]> wrote:
>>
>>> +static int cxacru_proc_read(struct usbatm_data *usbatm_instance,
>>> + struct atm_dev *atm_dev, loff_t * pos, char *page)
>>> +{
>>> + struct cxacru_data *instance = usbatm_instance->driver_data;
>>> + u32 *cxinf = instance->cxinf_status;
>>> + int left = *pos;
>>> +
>>> + if (!left--)
>>> + return sprintf(page, "# %s\n", usbatm_instance->description);
>>> +
>>> + if (!left--) {
>>> + if (cxinf[CXINF_LINE_STATUS] == 5) {
>>> + return sprintf(page, "# UP %u/%u\n",
>>> + cxinf[CXINF_DOWNSTREAM_RATE],
>>> + cxinf[CXINF_UPSTREAM_RATE]);
>>> + } else {
>>> + return sprintf(page, "# DOWN\n");
>>> + }
>>> + }
>> hm, how well-tested was this proc interface? The pread() and lseek()
>> behaviour might be strange.
>>
>> I guess as long as it doesn't oops, hang or anything like that then it'll
>> be OK. Anyone who does anything apart from a single big-fat-read from a
>> procfile has a good chance of getting into trouble :(
Well, several reads of at least 172B... but that scenario works without any
problems.
> All the ATM drivers seem to do it like this. That doesn't mean they are
> right of course! But I never saw anyone complain on the ATM mailing list.
I just copied it from usbatm; it looks like this could be done using seq_file
instead.
> On the other hand, why does Simon want this? If he has written a user space
> tool that extracts bits from the proc file (eg: to tell users what's going
> on) then he could run into trouble, depending on how he implements it.
No special user space tool, I just want other people to be able to get the same
useful line information from cxacru that most ADSL driver have. (I do have a
small "cxacru-watch" program which execs "cmd.up" etc. on status changes, but
that is just sent printks via syslog-ng).
It looks like the weird proc interface prevents my intention to allow ".
/proc/net/atm/cxacru\:0" to work and set $LINE_STATUS etc., at least with bash:
open("/proc/net/atm/cxacru:0", O_RDONLY|O_LARGEFILE) = 3
fstat64(3, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0
read(3, "", 0) = 0
close(3) = 0
Does anyone have any thoughts on the output format? The standard usbatm output
isn't going to be compatible with the above if a common MAC/AAL5 header were
used.
When I have the time and can acquire another conexant usb modem for testing
I'll fix the usbatm /proc interfaces. It would be also good if the module could
reliably be reloaded - most (but not all) of the time it fails to initialise
the device again.
There's still an issue with khubd going into a loop if the firmware doesn't
exist or if the device is unplugged.
--
Simon Arlott
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