Re: [PATCH 0/3] Intel SPI unbind fixes

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Mon, May 25, 2020 at 02:25:00PM +0200, Lukas Wunner wrote:
> Fix unbind ordering issues in the Designware and PXA2xx SPI controllers
> built into Intel SoCs.
> 
> To test, you'll also need the following commit:
> https://git.kernel.org/broonie/spi/c/84855678add8
> 
> This is compile-tested only, so please review and test thoroughly.
> 
> Pay particular attention to the IRQ handlers dw_spi_irq() and ssp_int():
> Both drivers request the interrupt with IRQF_SHARED, so the IRQ handler
> may run even though the SPI controller itself hasn't signalled an
> interrupt.  The IRQ is requested before registering the controller and
> freed after unregistering the controller.  Thus, the IRQ handler should
> immediately bail out if the controller is not yet or no longer registered,
> e.g. by checking in the controller's registers whether an interrupt is
> actually pending.  The drivers may need to disable interrupts in the
> controllers' registers upon unbinding and they need to make sure that
> the registers are accessible until the IRQ is freed.
> 
> I don't have a datasheet for these SPI controllers but I hope someone
> who is more familiar with them will be able to check for correctness
> of the IRQ handling.

Thank you for this!
I reviewed all three, but I have no means to reliably test it. From the
description and logic point of view this sounds correct. So, let's wait for
Tsuchiya Yuto to test and confirm that it's right way to go.

> 
> Lukas Wunner (3):
>   spi: dw: Fix controller unregister order
>   spi: pxa2xx: Fix controller unregister order
>   spi: pxa2xx: Fix runtime PM ref imbalance on probe error
> 
>  drivers/spi/spi-dw.c     | 4 +++-
>  drivers/spi/spi-pxa2xx.c | 5 +++--
>  2 files changed, 6 insertions(+), 3 deletions(-)
> 
> -- 
> 2.25.0
> 

-- 
With Best Regards,
Andy Shevchenko