github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-11-07 06:17:02 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

rtc: mpfs: Fix alarm register word order

Browse Source 
mpfs_rtc_readalarm() swaps the low and high words of the alarm time.
The RTC core reads this value during device registration to initialize
its alarm timer. This can populate the cached alarm and timer queue
with an incorrect expiry time, or leave an enabled hardware alarm out
of the timer queue if the decoded time appears to be in the past.

Read the low 32 bits from ALARM_LOWER_REG and place the masked high
11 bits from ALARM_UPPER_REG in bits 42:32. This matches the layout
used by mpfs_rtc_setalarm() and the low/high assembly in
mpfs_rtc_readtime(), so the RTC core imports the programmed alarm
time correctly during device registration.

Fixes: 0b31d70359 ("rtc: Add driver for Microchip PolarFire SoC")
Signed-off-by: Baek Kyu, Kim <pocj8ur4in@gmail.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/20261019151024.2232338-1-pocj8ur4in@gmail.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Baek Kyu, Kim 2026-10-20 00:10:24 +09:00 committed by Alexandre Belloni
parent 99473f37cc
commit d691a96370
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/rtc/rtc-mpfs.c
View File

@ -131,8 +131,8 @@ static int mpfs_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
alrm->enabled = mode & MODE_WAKE_EN;
time = (u64)readl(rtcdev->base + ALARM_LOWER_REG) << 32;
time |= (readl(rtcdev->base + ALARM_UPPER_REG) & ALARM_UPPER_MASK);
time = readl(rtcdev->base + ALARM_LOWER_REG);
time |= ((u64)readl(rtcdev->base + ALARM_UPPER_REG) & ALARM_UPPER_MASK) << 32;
rtc_time64_to_tm(time, &alrm->time);
return 0;