Re: [PATCH] iio: Fix the sorting functionality in iio_gts_build_avail_time_table

[Matti Vaittinen <mazziesaccount@gmail.com>]

Hi Jonathan, all.

I am resending this as I don't think I found the mail from lore. I wrote 
this using my phone so maybe it was sent as HTML and stuck to some 
filters. If you receive this twice - I am sorry...

la 16. maalisk. 2024 klo 15.40 Jonathan Cameron <jic23@kernel.org 
<mailto:jic23@kernel.org>> kirjoitti:

 > On Fri, 15 Mar 2024 15:49:10 -0500
 > Chenyuan Yang <chenyuan0y@gmail.com <mailto:chenyuan0y@gmail.com>>
 > wrote:
 >
 > > Hi Matti,
 > >
 > > Thanks for your reply!
 > >
 > > > I think the suggested-by tag is a bit of an overkill :) I don't feel
 > > > like taking the credit - you spotted the problem and fixed it!
 > >
 > > You did help me figure out the real issue here and how to fix it :)
 > >
 > > > Do you think you could fix the removal of the duplicates too?
 > >
 > > Sure, I can help to implement the deduplication logic.
 > > Here is a potential patch for it based on your help.
 > > Besides, I changed the stop condition in the inner loop to `j < idx`
 > > since the current last index should be `idx - 1`.
 >
 > Matti, I didn't follow why duplicates are a problem?

The function here builds the tables for available integration times. 
These are shown to users via sysfs (if I'm not mistaken) - and while the 
user-space algorithms may tolerate dublicates, they are ugly (in my 
opinon) when available times are manually listed.


 > Sure the code is less efficient, but do we end up with a wrong
 > answer as a result (I've not checked logic, but I'd expect either
 > first or last of repeating values to be used depending on the alg).

If we discuss completely omitting duplicated times from the driver 
(which was one thing I referred in my previous mail) - then we are 
likely to face problems as there can be register values, which then 
can't be translated to times, read from a HW.

Eg, we need to have everything described in driver tables used for 
driver's computations - but (in my opinion) we should drop duplicates 
from these tables which we hand over via sysfs.

Yours,
-- Matti