> -----Original Message----- > From: Greg KH [mailto:greg@xxxxxxxxx] > Sent: Tuesday, October 10, 2017 8:59 AM > To: Limonciello, Mario <Mario_Limonciello@xxxxxxxx> > Cc: dvhart@xxxxxxxxxxxxx; Andy Shevchenko <andy.shevchenko@xxxxxxxxx>; > LKML <linux-kernel@xxxxxxxxxxxxxxx>; platform-driver-x86@xxxxxxxxxxxxxxx; > Andy Lutomirski <luto@xxxxxxxxxx>; quasisec@xxxxxxxxxx; > pali.rohar@xxxxxxxxx; rjw@xxxxxxxxxxxxx; mjg59@xxxxxxxxxx; hch@xxxxxx > Subject: Re: [PATCH v6 14/14] platform/x86: dell-smbios-wmi: introduce > userspace interface > > On Mon, Oct 09, 2017 at 05:51:52PM -0500, Mario Limonciello wrote: > > + ret = device_create_file(&wdev->dev, &priv->req_buf_size_attr); > > + if (ret) > > + goto fail_create_sysfs; > > Why isn't the "WMI core" creating this sysfs file? Why have per-driver > sysfs files, making all of the different apis totally different? It's a > "common" attribute that they are all going to have to provide, right? > I hadn't really thought about that. I suppose it's entirely reasonable to have a way that all WMI ioctls for future drivers will advertise the size of their expected buffer the same way. So this does beg a question to others on this distribution who have worked on WMI drivers- do you know of any WM**/ methods with multiple instances that use different buffer sizes, or is it reasonable to expect that the buffer size is consistent between instances? Even in advanced MOF designs I haven't seen it, but this makes me wonder if an attribute should be created for every instance to be future proof. (For example $GUID/required_buffer_size/instance0, $GUID/required_buffer_size/instance1 etc) > That way you also don't race with userspace :) > > thanks, > > greg k-h
