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| author |   Jarkko Nikula <jarkko.nikula@linux.intel.com> | 2018-11-01 16:36:36 +0200 |
|---|---|---|
| committer |   Mark Brown <broonie@kernel.org> | 2018-11-05 11:50:51 +0000 |
| commit | b53548f9d9e4ca9203095afe2fadc97c982d50ee (patch) | |
| tree | 5cab5a19457d011a7cf7deb66c90e08f969304b8 | |
| parent | spi: rockchip: support lsb-first mode (diff) | |
| download | linux-dev-b53548f9d9e4ca9203095afe2fadc97c982d50ee.tar.xz linux-dev-b53548f9d9e4ca9203095afe2fadc97c982d50ee.zip | |
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:
c78b0830667a ("ACPI / LPSS: custom power domain for LPSS")
41a3da2b8e16 ("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>
| -rw-r--r-- | drivers/spi/spi-pxa2xx.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c index 612cc49db28f..d46af116d630 100644 --- a/drivers/spi/spi-pxa2xx.c +++ b/drivers/spi/spi-pxa2xx.c @@ -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); } |