Hi,
On 10-Nov-24 12:51 PM, Andy Shevchenko wrote:
> On Sun, Nov 10, 2024 at 12:05 AM Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
>>
>> On the Vexia EDU ATLA 10 tablet, which ships with Android + a custom Linux
>> (guadalinex) using the custom Android kernel the UART controllers are not
>> enumerated as ACPI devices as they typically are.
>>
>> Instead they are enumerated through PCI and getting the serdev-controller
>> by ACPI HID + UID does not work.
>>
>> Add support for getting the serdev-controller by the PCI devfn of its
>> parent instead.
>>
>> This also renames the use_pci_devname flag to use_pci since the former
>> name now no longer is accurate.
>
> ...
>
>> + if (dev_info->use_pci)
>> + ctrl_dev = get_serdev_controller_by_pci_parent(info);
>> + else
>> + ctrl_dev = get_serdev_controller(info->ctrl_hid, info->ctrl_uid, 0,
>> + info->ctrl_devname);
>
> I would expect that they both take info as an argument...
The "old" get_serdev_controller() helper for getting the controller
by ACPI HID + UID is also used outside of the x86-android-tablets code
and struct x86_serdev_info is x86-android-tablets specific.
>> if (IS_ERR(ctrl_dev))
>> return PTR_ERR(ctrl_dev);
>
> ...
>
>> struct x86_serdev_info {
>> + /* For ACPI enumerated controllers */
>> const char *ctrl_hid;
>> const char *ctrl_uid;
>> + /* For PCI enumerated controllers */
>> + unsigned int ctrl_devfn;
>> + /* Typically "serial0" */
>> const char *ctrl_devname;
>
> Why not union as we have a type selector, i.e. use_pci ?
A union would be possible. I simply did not think of that.
Not sure if it is worth the trouble though, since it saves
only 8 bytes on a struct which is currently used only 3
times in the driver.
Regards,
Hans
