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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:

c78b083066 ("ACPI / LPSS: custom power domain for LPSS")
41a3da2b8e ("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>
hifive-unleashed-5.1
Jarkko Nikula 2018-11-01 16:36:36 +02:00 committed by Mark Brown
parent 04290192f7
commit b53548f9d9
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1 changed files with 0 additions and 4 deletions
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4
drivers/spi/spi-pxa2xx.c
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@ -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);
}