From 9f8010e71f091b0609452742cfed4650ee633c44 Mon Sep 17 00:00:00 2001 From: Thomas Bogendoerfer Date: Thu, 10 Sep 2020 10:41:24 +0200 Subject: rtc: ds1685: Fix bank switching to avoid endless loop ds1685_rtc_begin_data_access() tried to access an extended register before enabling access to it by switching to bank 1. Depending on content in NVRAM this could lead to an endless loop. While at it fix also switch back to bank 0 in ds1685_rtc_end_data_access(). Signed-off-by: Thomas Bogendoerfer Signed-off-by: Alexandre Belloni Acked-by: Joshua Kinard Link: https://lore.kernel.org/r/20200910084124.138560-1-tsbogend@alpha.franken.de --- drivers/rtc/rtc-ds1685.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/rtc/rtc-ds1685.c') diff --git a/drivers/rtc/rtc-ds1685.c b/drivers/rtc/rtc-ds1685.c index 56c670af2e50..dfbd7b88b2b9 100644 --- a/drivers/rtc/rtc-ds1685.c +++ b/drivers/rtc/rtc-ds1685.c @@ -193,12 +193,12 @@ ds1685_rtc_begin_data_access(struct ds1685_priv *rtc) rtc->write(rtc, RTC_CTRL_B, (rtc->read(rtc, RTC_CTRL_B) | RTC_CTRL_B_SET)); + /* Switch to Bank 1 */ + ds1685_rtc_switch_to_bank1(rtc); + /* Read Ext Ctrl 4A and check the INCR bit to avoid a lockout. */ while (rtc->read(rtc, RTC_EXT_CTRL_4A) & RTC_CTRL_4A_INCR) cpu_relax(); - - /* Switch to Bank 1 */ - ds1685_rtc_switch_to_bank1(rtc); } /** @@ -213,7 +213,7 @@ static inline void ds1685_rtc_end_data_access(struct ds1685_priv *rtc) { /* Switch back to Bank 0 */ - ds1685_rtc_switch_to_bank1(rtc); + ds1685_rtc_switch_to_bank0(rtc); /* Clear the SET bit in Ctrl B */ rtc->write(rtc, RTC_CTRL_B, -- cgit v1.2.3