From: Tony Lindgren tony@atomide.com
[ Upstream commit c8692ad416dcc420ce1b403596a425c8f4c2720b ]
Looks like the swsup_sidle_act quirk handling is unreliable for serial ports. The serial ports just eventually stop idling until woken up and re-idled again. As the serial port not idling blocks any deeper SoC idle states, it's adds an annoying random flakeyness for power management.
Let's just switch to swsup_sidle quirk instead like we already do for omap3 uarts. This means we manually idle the port instead of trying to use the hardware autoidle features when not in use.
For more details on why the serial ports have been using swsup_idle_act, see commit 66dde54e978a ("ARM: OMAP2+: hwmod-data: UART IP needs software control to manage sidle modes"). It seems that the swsup_idle_act quirk handling is not enough though, and for example the TI Android kernel changed to using swsup_sidle with commit 77c34c84e1e0 ("OMAP4: HWMOD: UART1: disable smart-idle.").
Fixes: b4a9a7a38917 ("bus: ti-sysc: Handle swsup idle mode quirks") Cc: Carl Philipp Klemm philipp@uvos.xyz Cc: Ivan Jelincic parazyd@dyne.org Cc: Merlijn Wajer merlijn@wizzup.org Cc: Pavel Machek pavel@ucw.cz Cc: Sebastian Reichel sre@kernel.org Cc: Sicelo A. Mhlongo absicsz@gmail.com Signed-off-by: Tony Lindgren tony@atomide.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/bus/ti-sysc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c index b7f8c6074a15..818dc7f54f03 100644 --- a/drivers/bus/ti-sysc.c +++ b/drivers/bus/ti-sysc.c @@ -1450,9 +1450,9 @@ static const struct sysc_revision_quirk sysc_revision_quirks[] = { SYSC_QUIRK_SWSUP_SIDLE | SYSC_QUIRK_LEGACY_IDLE), /* Uarts on omap4 and later */ SYSC_QUIRK("uart", 0, 0x50, 0x54, 0x58, 0x50411e03, 0xffff00ff, - SYSC_QUIRK_SWSUP_SIDLE_ACT | SYSC_QUIRK_LEGACY_IDLE), + SYSC_QUIRK_SWSUP_SIDLE | SYSC_QUIRK_LEGACY_IDLE), SYSC_QUIRK("uart", 0, 0x50, 0x54, 0x58, 0x47422e03, 0xffffffff, - SYSC_QUIRK_SWSUP_SIDLE_ACT | SYSC_QUIRK_LEGACY_IDLE), + SYSC_QUIRK_SWSUP_SIDLE | SYSC_QUIRK_LEGACY_IDLE),
/* Quirks that need to be set based on the module address */ SYSC_QUIRK("mcpdm", 0x40132000, 0, 0x10, -ENODEV, 0x50000800, 0xffffffff,