Messages in this thread | | | From | Andy Shevchenko <> | Date | Tue, 16 Oct 2018 16:42:41 +0300 | Subject | Re: [PATCH 2/3] driver core: add deferring probe reason to devices_deferred property |
| |
On Tue, Oct 16, 2018 at 10:22 AM Andrzej Hajda <a.hajda@samsung.com> wrote: > > /sys/kernel/debug/devices_deferred property contains list of deferred devices. > This list does not contain reason why the driver deferred probe, the patch > improves it. > The natural place to set the reason is probe_err function introduced recently, > ie. if probe_err will be called with -EPROBE_DEFER instead of printk the message > will be attached to deferred device and printed when user read devices_deferred > property.
> - if (err != -EPROBE_DEFER) { > - va_start(args, fmt); > + va_start(args, fmt); > > - vaf.fmt = fmt; > - vaf.va = &args; > + vaf.fmt = fmt; > + vaf.va = &args; > > + if (err != -EPROBE_DEFER) > __dev_printk(KERN_ERR, dev, &vaf); > - va_end(args); > - } > + else > + __deferred_probe_set_msg(dev, fmt, args); > + > + va_end(args);
Yeah, ping-pong style of programming (one patch "amends" something which had been introduced by another). That's why better to follow my comment for the patch 1.
> +/* > + * __deferred_probe_set_msg() - Set defer probe reason message for device > + */ > +void __deferred_probe_set_msg(const struct device *dev, const char *fmt, > + va_list args) > +{ > + const int size = 128; > + char **p; > + int n; > + > + mutex_lock(&deferred_probe_mutex); > +
> + p = &dev->p->deferred_probe_msg; > + if (!*p) { > + *p = kmalloc(size, GFP_KERNEL); > + if (!*p) > + goto end; > + } > + n = snprintf(*p, size, "%s %s: ", dev_driver_string(dev), dev_name(dev)); > + if (n < size) > + vsnprintf(*p + n, size - n, fmt, args);
Perhaps kasprintf() instead of this huge plays around the size and allocation?
> list_for_each_entry(curr, &deferred_probe_pending_list, deferred_probe) > - seq_printf(s, "%s\n", dev_name(curr->device)); > + if (curr->device->p->deferred_probe_msg) > + seq_puts(s, curr->device->p->deferred_probe_msg); > + else > + seq_printf(s, "%s\n", dev_name(curr->device));
I wouldn't care (much) about debugfs, though better to keep some order here, i.e. always print device name.
Something like
seq_printf(s, "%s\t%s\n", dev_name(), deferred_probe_msg ?: "");
and remove that part from above __deferred_probe_set_msg().
-- With Best Regards, Andy Shevchenko
| |