[lkml]   [2020]   [Dec]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [BUG] SPI broken for SPI based panel drivers
Hi Sven,

> Am 01.12.2020 um 17:53 schrieb Sven Van Asbroeck <>:
> Hi Nikolaus,
> On Tue, Dec 1, 2020 at 11:43 AM H. Nikolaus Schaller <> wrote:
>> You are right. It is active low.
> In that case, we have a very simple solution, just remove the spi-cs-high,
> and things will work.

We originally had it that way and because there was a change in gpiolib we had
to introduce it.

See: f1f028ff89cb0d3

where we were forced to introduce it although I had preferred to not change DT.

I am not sure if DT maintainers accept that we revert a DT change just to
handle some change in a driver. Usually they insist on fixing a driver and
live with the DT. DT is carved in stone or could be ROM...

So you could try to submit a revert of f1f028ff89cb0d3 with a description
why it is needed. And please make sure that it is also applied where your
patch is backported to stable. So it should have some

Fixes: 766c6b63aa04 ("spi: fix client driver breakages when using GPIO descriptors")

> In case of SPI CS gpios, the current kernel ignores all
> flags, and uses the presence/absence of spi-cs-high instead, to
> determine active high / active low.

So you mean you are just restoring the behaviour before


was introduced?

The alternative is that you restore the cs-gpios + spi-cs-high semantics
as defined by 6953c57ab172 and everything is fine without touching (our)
DTS (again).

BR and thanks,

 \ /
  Last update: 2020-12-01 18:14    [W:0.102 / U:0.320 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site