Hi Laurent, We will be adding a way to check features that are available in firmware from kernel drivers in the near-future. Once that ability is available, kernel drivers can query if a feature is supported in the firmware before making use of the feature. We will revert this patch at this time as existing (& older released) firmwares neither supports this particular pinctrl tristate feature or the ability to check for available features. Regards, Arun > -----Original Message----- > From: Simek, Michal <michal.simek@xxxxxxx> > Sent: Thursday, September 29, 2022 12:08 AM > To: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>; Sai Krishna > Potthuri <lakshmi.sai.krishna.potthuri@xxxxxxxxxx>; Kannan, Arun Balaji > <arun.balaji.kannan@xxxxxxx>; Mutthareddyvari, Jyotheeswar Reddy > <jyotheeswar.reddy.mutthareddyvari@xxxxxxx> > Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>; Rob Herring <robh+dt@xxxxxxxxxx>; > Michal Simek <michal.simek@xxxxxxxxxx>; Krzysztof Kozlowski > <krzysztof.kozlowski+dt@xxxxxxxxxx>; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux- > gpio@xxxxxxxxxxxxxxx; git@xxxxxxxxxx; saikrishna12468@xxxxxxxxx > Subject: Re: [PATCH 0/4] pinctrl: pinctrl-zynqmp: Add tri-state configuration > support > > Hi Laurent, > > On 9/28/22 18:42, Laurent Pinchart wrote: > > > > On Wed, Sep 28, 2022 at 06:58:10PM +0300, Laurent Pinchart wrote: > >> Hi Sai, > >> > >> On Fri, Jun 17, 2022 at 04:16:55PM +0530, Sai Krishna Potthuri wrote: > >>> This series update the Xilinx firmware, ZynqMP dt-binding and ZynqMP > >>> pinctrl driver to handle 'output-enable' and 'bias-high-impedance' > >>> configurations. As part of these configurations, ZynqMP pinctrl > >>> driver takes care of pin tri-state setting. > >>> Also fix the kernel doc warning in ZynqMP pinctrl driver. > >> > >> I'm afraid this causes a regression :-( With this series applied, > >> boot breaks with the following message being printed to the serial console: > >> > >> Received exception > >> MSR: 0x200, EAR: 0xFF180198, EDR: 0x0, ESR: 0x64 > >> > >> I've traced that to the probe of the UART, when it calls into the > >> firmware to set pin MIO18 to high impedance. According to v1.7 of the > >> ZynqMP registers reference (UG1087), there is no register at address > >> 0xFF180198. > >> > >> I am using the VCU TRD 2021.1 for testing. Does this series require a > >> firmware update ? If so backward compatibility needs to be preserved. > >> It's very late in the v6.0-rc cycle for a fix, a revert may be best > >> at this point, to give us time to fix the issue properly. > > > > I've now tested the VCU TRD 2022.1 (which AFAIK is the latest > > available version), and the problem doesn't occue then. It thus seems > > this depends on a firmware update, which is impractical at best for > > all old designs :-( > > That's correct observation. Supporting these two properties requires newer > pmufw or that message is received. > I will let Arun and Jyotheeswar to comment it. I don't think there is a way to > detect which firmware has implementation for it available. > > Thanks, > Michal
