Re: Fwd: [PATCH 0/2] sysfs: allow user-space request for devcoredump

[Greg KH]

On Tue, Jan 09, 2018 at 09:06:21PM +0100, Arend van Spriel wrote:
> On Tue, Jan 9, 2018 at 9:03 PM, Greg KH <greg@xxxxxxxxx> wrote:
> > On Tue, Jan 09, 2018 at 08:21:11PM +0100, Arend van Spriel wrote:
> >> + LKML
> >>
> >> ---------- Forwarded message ----------
> >> From: Arend van Spriel <aspriel@xxxxxxxxx>
> >> Date: Tue, Jan 9, 2018 at 8:19 PM
> >> Subject: Re: [PATCH 0/2] sysfs: allow user-space request for devcoredump
> >> To: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> >>
> >>
> >> On Tue, Jan 9, 2018 at 7:46 PM, Greg Kroah-Hartman
> >> <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> >> > On Tue, Dec 19, 2017 at 11:03:20AM +0100, Arend van Spriel wrote:
> >> >> From: Arend van Spriel <aspriel@xxxxxxxxx>
> >> >>
> >> >> Since commit 833c95456a70 ("device coredump: add new device coredump class")
> >> >> device drivers have a unified way to provide binary data obtained from a
> >> >> failing_device to user-space. However, there may be use-cases in which the
> >> >> driver has no reason to obtain the data, but user-space wants to initiate
> >> >> it. This adds a coredump device attribute in sysfs when the driver bound to
> >> >> the device supports the newly added coredump driver callback.
> >> >
> >> > What driver is going to set this?  I don't want to add new options to
> >> > the kernel that never get used, do you have a driver to use it?
> >>
> >> Hi Greg,
> >>
> >> After sending these patches I realized that was going to be your
> >> response, but decided to wait for it. Obviously there is a driver for
> >> which I would like to have an option to create a device coredump from
> >> user-space, ie. the brcm80211 drivers (maintained by my alter-ego ;-)
> >> ). I can post these patches again as RFC including the brcm80211
> >> driver patches. Here a bit of background about this itch. A couple of
> >> other driver support their own coredump implementation, ie. not using
> >> dev_coredump class and some support user-space initiated coredump
> >> through debugfs. As that depends on a Kconfig option I looked for
> >> other solutions. At first I considered doing it in dev_coredump class
> >> itself by doing:
> >>
> >> # echo 0000:04:00.0 > /sys/class/devcoredump/trigger
> >>
> >> with 'trigger' being a new sysfs attribute for devcoredump. However,
> >> using the driver core turned out to be much simpler, but I am still
> >> open for other/better options.
> >
> > Nah, I don't object to the patches, but I want someone to use it.  So
> > can you resend these, with a RFC for the driver you want using it as the
> > last patch?
> 
> Thanks. Will do that. FWIW, there are a couple more drivers that I
> would like to change to using this as well.

Great, do it for all of them!