Unverified Commit b53548f9 authored Nov 01, 2018 by Jarkko Nikula Committed by Mark Brown Nov 05, 2018

spi: pxa2xx: Remove LPSS private register restoring during resume

Intel LPSS private register restoring in spi-pxa2xx.c: pxa2xx_spi_resume()
was added before there was no any other code restoring them. This was
changed after following commits for previous and current LPSS platforms:

c78b0830 ("ACPI / LPSS: custom power domain for LPSS")
41a3da2b ("mfd: intel-lpss: Save register context on suspend")

However there is one caveat: There is no LPSS private register context
save/restore for the Intel Lynxpoint in the Linux kernel code.

I did some debugging on one Lynxpoint based device I have and on it the
LPSS register context is not lost over suspend/resume cycle (s2idle).
Which happens for instance on Intel Braswell. I'm speculating but I guess
either firmware does it or the LPSS is kept always on Lynxpoint.

Given that we haven't needed to implement Lynxpoint LPSS I2C or UART
private register context save/restore over four years time I think we are
safe to remove this LPSS private register restoring during resume here.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

parent 04290192

drivers/spi/spi-pxa2xx.c

+0 −4

Original line number	Diff line number	Diff line
		@@ -1811,10 +1811,6 @@ static int pxa2xx_spi_resume(struct device *dev)
		return status;
		}

		/* Restore LPSS private register bits */
		if (is_lpss_ssp(drv_data))
		lpss_ssp_setup(drv_data);

		/* Start the queue running */
		return spi_controller_resume(drv_data->master);
		}

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