Re: [PATCH v16 3/7] spi: pxa2xx: overhaul teardown and suspend sequence using pxa2xx_spi_off

[Andy Shevchenko]

On Tue, Jul 21, 2026 at 12:21:12AM +0800, Shih-Yuan Lee wrote:
> When removing the driver or suspending the device, the clock must not
> be disabled while shared interrupts are still active. Gating the clock
> before waiting for in-flight interrupt handlers to complete results
> in race conditions where the handler performs unclocked MMIO accesses,
> causing PCIe Completion Timeouts.
> 
> Overhaul the remove, suspend, and runtime_suspend paths to use a strict
> synchronized teardown order:
> 1. Disable hardware interrupt generation at the controller level.
> 2. Mark the device state as suspended (suspended = true) to prevent
>    subsequent interrupt handlers from attempting MMIO reads.
> 3. Call synchronize_irq() to wait for any active interrupt handlers
>    to drain completely.
> 4. Gate the clock via pxa2xx_spi_clk_disable().
> 
> Additionally, commit 29d7e05c5f75 ("spi: pxa2xx: Avoid touching
> SSCR0_SSE on MMP2") documented that disabling the hardware block via SSE on
> MMP2 SoC platforms corrupts the RX/TX FIFO. Instead of calling
> pxa_ssp_disable() directly, use the helper function pxa2xx_spi_off(),
> which respects the MMP2 platform quirk by bypassing SSE register writes.

...

> +	/* Wait for any pending interrupt handlers to complete */
> +	synchronize_irq(ssp->irq);

Unneeded. free_irq() implies that.

> +	/* Release IRQ */
> +	free_irq(ssp->irq, drv_data);

-- 
With Best Regards,
Andy Shevchenko