Messages in this thread | | | Subject | Re: [PATCH v1 1/1] gpiolib: Read "gpio-line-names" from a firmware node | From | Marek Vasut <> | Date | Sat, 10 Apr 2021 02:45:58 +0200 |
| |
On 3/15/21 6:04 PM, Andy Shevchenko wrote: > On Mon, Mar 15, 2021 at 6:49 PM Bartosz Golaszewski > <bgolaszewski@baylibre.com> wrote: >> >> On Mon, Mar 15, 2021 at 3:34 PM Andy Shevchenko >> <andriy.shevchenko@linux.intel.com> wrote: >>> >>> On Mon, Mar 15, 2021 at 03:04:37PM +0100, Bartosz Golaszewski wrote: >>>> On Mon, Mar 15, 2021 at 1:50 PM Andy Shevchenko >>>> <andriy.shevchenko@linux.intel.com> wrote: >>>>> >>>>> On Mon, Mar 15, 2021 at 12:16:26PM +0200, Andy Shevchenko wrote: >>>>>> On Mon, Mar 15, 2021 at 10:01:47AM +0100, Bartosz Golaszewski wrote: >>>>>>> On Fri, Mar 5, 2021 at 1:03 PM Andy Shevchenko >>>>>>> <andriy.shevchenko@linux.intel.com> wrote: >>>>>> >>>>>>> Unfortunately while this may fix the particular use-case on STM32, it >>>>>>> breaks all other users as the 'gpio-line-names' property doesn't live >>>>>>> on dev_fwnode(&gdev->dev) but on dev_fwnode(chip->parent). >>>>>>> >>>>>>> How about we first look for this property on the latter and only if >>>>>>> it's not present descend down to the former fwnode? >>>>>> >>>>>> Oops, I have tested on x86 and it worked the same way. >>>>>> >>>>>> Lemme check this, but I think the issue rather in ordering when we apply fwnode >>>>>> to the newly created device and when we actually retrieve gpio-line-names >>>>>> property. >>>>> >>>>> Hmm... I can't see how it's possible can be. Can you provide a platform name >>>>> and pointers to the DTS that has been broken by the change? >>>>> >>>> >>>> I noticed it with gpio-mockup (libgpiod tests failed on v5.12-rc3) and >>>> the WiP gpio-sim - but it's the same on most DT platforms. The node >>>> that contains the `gpio-line-names` is the one associated with the >>>> platform device passed to the GPIO driver. The gpiolib then creates >>>> another struct device that becomes the child of that node but it >>>> doesn't copy the parent's properties to it (nor should it). >>>> >>>> Every driver that reads device properties does it from the parent >>>> device, not the one in gdev - whether it uses of_, fwnode_ or generic >>>> device_ properties. >>> >>> What you are telling contradicts with the idea of copying parent's fwnode >>> (or OF node) in the current code. >>> >> >> Ha! While the OF node of the parent device is indeed assigned to the >> gdev's dev, the same isn't done in the core code for fwnodes and >> simulated chips don't have an associated OF node, so this is the >> culprit I suppose. > > Close, but not fully correct. > First of all it depends on the OF / ACPI / platform enumeration. > Second, we are talking about secondary fwnode in the case where it happens. > > I'm in the middle of debugging this, I'll come up with something soon I believe.
Was there ever any follow up on this ?
I would like to point out that on STM32MP1 in Linux 5.10.y, the gpio-line-names are still broken, and a revert of "gpiolib: generalize devprop_gpiochip_set_names() for device properties" is still necessary.
| |