[tip:timers/urgent] clocksource/arm_arch_timer: Fix arch_timer_mem_find_best_frame()

From: tip-bot for Sudeep Holla
Date: Tue May 09 2017 - 03:03:15 EST


Commit-ID: f63d947c1673930bfc5f2f9bd1073a02c179a890
Gitweb: http://git.kernel.org/tip/f63d947c1673930bfc5f2f9bd1073a02c179a890
Author: Sudeep Holla <sudeep.holla@xxxxxxx>
AuthorDate: Mon, 8 May 2017 13:32:27 +0100
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Tue, 9 May 2017 08:56:41 +0200

clocksource/arm_arch_timer: Fix arch_timer_mem_find_best_frame()

arch_timer_mem_find_best_frame() looks through ARCH_TIMER_MEM_MAX_FRAMES
frames even after finding matches to ensure the best frame is chosen,
which means the variable frame will point to the last valid frame but
not necessarily the best frame.

On Juno, we get the following error as the wrong frame is returned as the
best frame from arch_timer_mem_find_best_frame():

arch_timer: Unable to map frame @ 0x0000000000000000
arch_timer: Frame missing phys irq.
Failed to initialize '/timer@2a810000': -22

Fix the issue by correctly returning the best frame from
arch_timer_mem_find_best_frame().

Fixes: c389d701dfb7 ("clocksource: arm_arch_timer: split MMIO timer probing.")
Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
Acked-by: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1494246747-17267-1-git-send-email-sudeep.holla@xxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
drivers/clocksource/arm_arch_timer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index a1fb918..4bed671 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -1268,7 +1268,7 @@ arch_timer_mem_find_best_frame(struct arch_timer_mem *timer_mem)
pr_err("Unable to find a suitable frame in timer @ %pa\n",
&timer_mem->cntctlbase);

- return frame;
+ return best_frame;
}

static int __init