Hi Martin, On Wed, Dec 27, 2017 at 3:27 PM, Martin Kaiser <martin@xxxxxxxxx> wrote: > Before we go into suspend mode, we enable the imx uart's interrupt for > the awake bit in the UART Status Register 1. If, for some reason, the > awake bit is already set before we enter suspend mode, we get an > interrupt immediately when we enable interrupts for awake. The uart's > clk_ipg is already disabled at this point. We end up in the interrupt > handler, which usually tries to clear the awake bit. This doesn't work > with the clock disabled. Therefore, we keep getting interrupts forever, > resulting in an endless loop. > > Move the calls to serial_imx_enable_wakeup() into the _noirq functions, > where interrupts are disabled and clk_ipg is active. This way, we can > safely clear the awake bit and enable the imx interrupt for awake. > > Now that we do the wakeup configuration in .suspend_noirq, we need > separate functions for .suspend_noirq and .freeze_noirq. However, > .resume_noirq and .restore_noirq can still be shared. We just disable > the wakeup source there, this does not conflict with hibernation. > > Signed-off-by: Martin Kaiser <martin@xxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx Which i.MX SoC did you use to test this patch? On a imx6q-cuboxi I am no longer able to enter in suspend with this path applied: # echo enabled > /sys/class/tty/ttymxc0/power/wakeup # echo mem > /sys/power/state [ 9.766903] PM: suspend entry (deep) [ 9.770658] PM: Syncing filesystems ... done. [ 9.815312] Freezing user space processes ... (elapsed 0.001 seconds) done. [ 9.824744] OOM killer disabled. [ 9.827998] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done. [ 9.837351] Suspending console(s) (use no_console_suspend to debug) [ 9.915495] PM: suspend devices took 0.080 seconds [ 9.928746] PM: noirq suspend of devices failed [ 10.196232] mmc0: queuing unknown CIS tuple 0x80 (2 bytes) [ 10.198148] mmc0: queuing unknown CIS tuple 0x80 (3 bytes) [ 10.200042] mmc0: queuing unknown CIS tuple 0x80 (3 bytes) [ 10.203420] mmc0: queuing unknown CIS tuple 0x80 (7 bytes) [ 10.206812] mmc0: queuing unknown CIS tuple 0x80 (7 bytes) [ 10.263097] PM: resume devices took 0.330 seconds [ 10.266639] ata1: SATA link down (SStatus 0 SControl 300) [ 10.310305] OOM killer enabled. [ 10.313458] Restarting tasks ... done. [ 10.319568] PM: suspend exit sh: write error: Device or resource busy Even if I do not press anything in the console the system gets out of suspend automatically. Thanks -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
