On Tue, 2018-10-30 at 20:33 +0200, Andy Shevchenko wrote: > On Tue, Oct 30, 2018 at 8:03 PM Srinivas Pandruvada > <srinivas.pandruvada@xxxxxxxxxxxxxxx> wrote: > > > > > Index printing is required here (for LTR Show and LTR Ignore) > > > > because it > > > > paves an obvious and easy way for the users of this driver to > > > > know > > > > the > > > > IP number to be used for LTR ignore. This was specifically > > > > requested by > > > > some customer and Srinivas asked me to implement this so adding > > > > him > > > > for > > > > his inputs. > > > > > > So, why it should be in kernel? When user prints this, they > > > usually > > > call `cat /.../file`, right? > > > Is it too hard to call `cat -n /.../file` instead? The benefit of > > > such > > > approach is that it's independent on the file we are printing. > > > > > > (Note, `grep -n <PATTERN> /.../file` does the same`) > > > > > > For more variants > > > > > > > https://stackoverflow.com/questions/8206370/add-numbers-to-the-beginning-of-every-line-in-a-file > > > > > > > We get copy/paste data from some serial terminals from systems > > which > > don't have traditional linux shell or busy box. Not sure if they > > can do > > cat "-n" option or have this command at all. So line number helps. > > They > > can't even store output as as file as this is RO file system. > > Hmm... I'm not following this. If there is serial connection where at > least you may see things, how it's guaranteed that it will not print > more enough to rewrite the DTE's input buffer? No guarantee, This is just best effort. We get something like this from emails: Device S-state Status Sysfs node BR1A S4 *disabled pci: 0000:00:01.0 BR1B S4 *disabled BR2A S4 *disabled pci: 0000:00:02.0 Any line marker helps. But again this is not a hard requirement. There will always be argument, that this can be done in other ways. For sake of time discussing this: Rajneesh, Please get rid of index printing. > On the other hand if you copy the data to the other system which, I > bet, has `cat -n` available, not a problem either. > > So, the use case here, AFAICS, if you have a debug log enabled and > it's spitted out like SysRq where you can see, but not able to copy > and it's guaranteed not to overflow on the screen / output device. > > > But I am not as sticky on this. > > Since it's a debugfs and not any ABI implied, I'm fine with it to > have, but I would like to understand the real use case of it (and > this > definitely should be reflected in the commit message). >
