Re: [PATCH] i2c: Allow recovery of the initial IRQ by a i2c client device.

[Charles Keepax]

On Fri, Feb 15, 2019 at 04:15:33PM -0800, Jim Broadus wrote:
> A previous change allowed i2c client devices to discover new IRQs upon
> reprobe. By clearing the IRQ in i2c_device_remove. However, if an IRQ was
> assigned in i2c_new_device, that information is lost.
> 
> For example, the touchscreen and trackpad devices on a Dell Inspiron laptop
> are I2C devices whose IRQs are defined by ACPI extended IRQ types. The
> client device structures are initialized during an ACPI walk. After
> removing the i2c_hid device, modprobe fails.
> 
> This change caches the initial IRQ value in i2c_new_device and then resets
> the client device IRQ to the initial value in i2c_device_remove.
> 
> Fixes: 6f108dd70d30 ("i2c: Clear client->irq in i2c_device_remove")
> Signed-off-by: Jim Broadus <jbroadus@xxxxxxxxx>
> ---

Reviewed-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>

Apologies for the issues caused. I think this looks like a good fix
to me.

Thanks,
Charles