rtc: rzn1: Fix alarm range check truncation on 32-bit systems

alarm and farest were declared as unsigned long, but
rtc_tm_to_time64() returns time64_t (s64). On 32-bit systems where
unsigned long is 32 bits, the assignment silently truncates the upper
32 bits of the timestamp.

Fix by declaring alarm and farest as time64_t and replacing
time_after() with a direct signed comparison, which is correct for
time64_t values that will never realistically overflow.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://patch.msgid.link/20260821211032.13554-6-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Lad Prabhakar 2026-08-21 22:10:20 +01:00 • committed by Alexandre Belloni
commit c3e735e9f6