Re: [PATCH 1/5] spi: Fix controller unregister order

[Lukas Wunner <lukas@xxxxxxxxx>]

On Fri, May 15, 2020 at 05:27:25PM +0100, Mark Brown wrote:
> On Fri, May 15, 2020 at 05:58:01PM +0200, Lukas Wunner wrote:
> > However since commit ffbbdd21329f ("spi: create a message queueing
> > infrastructure"), spi_destroy_queue() is executed before unbinding the
> > slaves.  It sets ctlr->running = false, thereby preventing SPI bus
> > access and causing unbinding of slave devices to fail.
> 
> Devices should basically never fail an unbind operation - if something
> went seriously wrong there's basically nothing that can be done in terms
> of error handling and keeping the device around isn't going to help.

I guess the word "fail" in the commit message invites misinterpretations.
The driver does unbind from the slave device, but the physical device is
not left in a proper state.  E.g. interrupts may still be generated by
the device because writing a register to disable them failed.

Thanks,

Lukas