clocksource: exynos_mct: Don't reset the counter during boot and resume
authorChirantan Ekbote <chirantan@chromium.org>
Wed, 11 Jun 2014 15:18:48 +0000 (00:18 +0900)
committerKukjin Kim <kgene.kim@samsung.com>
Mon, 16 Jun 2014 15:23:29 +0000 (00:23 +0900)
commit1d80415db64b54141ef02ae58bd2f273d0ac3c38
tree1f0447c05960c840b5d42807b783dd6bdf181161
parentcf286b405c446cc2c61e4ab210ef42e5852a6da3
clocksource: exynos_mct: Don't reset the counter during boot and resume

Unfortunately on some exynos systems, resetting the mct counter also
resets the architected timer counter.  This can cause problems if the
architected timer driver has already been initialized because the kernel
will think that the counter has wrapped around, causing a big jump in
printk timestamps and delaying any scheduled clock events until the
counter reaches the value it had before it was reset.

The kernel code makes no assumptions about the initial value of the mct
counter so there is no reason from a software perspective to clear the
counter before starting it.  This also fixes the problems described in
the previous paragraph.

Cc: Olof Johansson <olof@lixom.net>
Cc: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Chirantan Ekbote <chirantan@chromium.org>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Tested-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
drivers/clocksource/exynos_mct.c