Commit 48a7f7746875425797aea31ed2910088635c1c7a
Committed by
Linus Torvalds
Linus Torvalds
1 parent
0a1f127a05
Exists in
master
and in
4 other branches
rtc-x1205: fix rtc_time to y2k register value conversion
The possible CCR_Y2K register values are 19 or 20 and struct rtc_time's tm_year is in years since 1900. The function translating rtc_time to register values assumes tm_year to be years since first christmas, though, and we end up storing 0 or 1 in the CCR_Y2K register, which the hardware does not refuse to do. A subsequent probing of the clock fails due to the invalid value range in the register, though. [ And if it didn't, reading the clock would yield a bogus year because the function translating registers to tm_year is assuming a register value of 19 or 20. ] This fixes the conversion from years since 1900 in tm_year to the corresponding CCR_Y2K value of 19 or 20. Signed-off-by: Johannes Weiner <jw@emlix.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Paul Gortmaker <p_gortmaker@yahoo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Showing 1 changed file with 1 additions and 1 deletions Side-by-side Diff
drivers/rtc/rtc-x1205.c
| ... | ... | @@ -195,7 +195,7 @@ |
| 195 | 195 | /* year, since the rtc epoch*/ |
| 196 | 196 | buf[CCR_YEAR] = bin2bcd(tm->tm_year % 100); |
| 197 | 197 | buf[CCR_WDAY] = tm->tm_wday & 0x07; |
| 198 | - buf[CCR_Y2K] = bin2bcd(tm->tm_year / 100); | |
| 198 | + buf[CCR_Y2K] = bin2bcd((tm->tm_year + 1900) / 100); | |
| 199 | 199 | } |
| 200 | 200 | |
| 201 | 201 | /* If writing alarm registers, set compare bits on registers 0-4 */ |