From b53548f9d9e4ca9203095afe2fadc97c982d50ee Mon Sep 17 00:00:00 2001 From: Jarkko Nikula Date: Thu, 1 Nov 2018 16:36:36 +0200 Subject: [PATCH] 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 Acked-by: Andy Shevchenko Signed-off-by: Mark Brown --- drivers/spi/spi-pxa2xx.c | 4 ---- 1 file changed, 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); } -- 2.30.2