This is a note to let you know that I have just added a patch titled
tick-common: Fix wrong check in tick_check_replacement()
to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree
which can be found at:
http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/lin…
This patch is scheduled to be released in version 3.13.11.3.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Kamal
------
>From a7a150dca33ba90ecf23eb27b055c1a3267cb263 Mon Sep 17 00:00:00 2001
From: Viresh Kumar <viresh.kumar(a)linaro.org>
Date: Tue, 15 Apr 2014 10:54:37 +0530
Subject: tick-common: Fix wrong check in tick_check_replacement()
commit 521c42990e9d561ed5ed9f501f07639d0512b3c9 upstream.
tick_check_replacement() returns if a replacement of clock_event_device is
possible or not. It does this as the first check:
if (tick_check_percpu(curdev, newdev, smp_processor_id()))
return false;
Thats wrong. tick_check_percpu() returns true when the device is
useable. Check for false instead.
[ tglx: Massaged changelog ]
Signed-off-by: Viresh Kumar <viresh.kumar(a)linaro.org>
Cc: linaro-kernel(a)lists.linaro.org
Cc: fweisbec(a)gmail.com
Cc: Arvind.Chauhan(a)arm.com
Cc: linaro-networking(a)linaro.org
Link: http://lkml.kernel.org/r/486a02efe0246635aaba786e24b42d316438bf3b.139753798…
Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de>
Signed-off-by: Kamal Mostafa <kamal(a)canonical.com>
---
kernel/time/tick-common.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 162b03a..425bfae 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -275,7 +275,7 @@ static bool tick_check_preferred(struct clock_event_device *curdev,
bool tick_check_replacement(struct clock_event_device *curdev,
struct clock_event_device *newdev)
{
- if (tick_check_percpu(curdev, newdev, smp_processor_id()))
+ if (!tick_check_percpu(curdev, newdev, smp_processor_id()))
return false;
return tick_check_preferred(curdev, newdev);
--
1.9.1
Dear all,
There's a question in the arch/arm64/kernel/entry.S as following,
/*
* EL1 mode handlers.
*/
el1_sync:
kernel_entry 1
mrs x1, esr_el1 // read the syndrome register
lsr x24, x1, #ESR_EL1_EC_SHIFT // exception class
cmp x24, #ESR_EL1_EC_DABT_EL1 // data abort in EL1
b.eq el1_da
cmp x24, #ESR_EL1_EC_SYS64 // configurable trap
b.eq el1_undef
cmp x24, #ESR_EL1_EC_SP_ALIGN // stack alignment exception
b.eq el1_sp_pc
el1_sp_pc:
/*
* Stack or PC alignment exception handling
*/
mrs x0, far_el1
- mov x1, x25 ==> this is an extra operation
mov x2, sp
b do_sp_pc_abort //Jump to C Exception handler
/**The C Exception Handler/
asmlinkage void __exception do_sp_pc_abort(unsigned long addr,
unsigned int esr,
struct pt_regs *regs)
{
...
}
We use x1 register to store the value of ESR, and check the value to identify which exception handler to jump,
And there's a weird part In stack alignment exception handler(el1_sp_pc),
Why do we need to move x25 to x1?
The ESR has been stored into x1, and should be directly pass to do_sp_pc_abort function
"MOV x1, x25" is an extra operation and do_sp_pc_abort would get the wrong value of esr...
I'm not sure whether I'm right or not, hope someone can take a look at it, thx
BRs
andy
cpufreq-cpu0 uses thermal framework to register a cooling device, but doesn't
depend on it as there are dummy calls provided by thermal layer when
CONFIG_THERMAL=n. And when these calls fail, the driver is still usable.
Similar explanation is valid for regulators as well. We do have dummy calls
available for regulator APIs and the driver can work even when those calls
fail.
So, we don't really need to mention thermal and regulators as a dependency for
cpufreq-cpu0 in Kconfig as platforms without support for thermal/regulator can
also use this driver. Remove this dependency.
Signed-off-by: Viresh Kumar <viresh.kumar(a)linaro.org>
---
Rafael,
The dependency patches from regulators core are already pushed to Linus's tree
and so this patch can go in now.
drivers/cpufreq/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index 1fbe11f..e473d65 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -185,7 +185,7 @@ config CPU_FREQ_GOV_CONSERVATIVE
config GENERIC_CPUFREQ_CPU0
tristate "Generic CPU0 cpufreq driver"
- depends on HAVE_CLK && REGULATOR && OF && THERMAL && CPU_THERMAL
+ depends on HAVE_CLK && OF
select PM_OPP
help
This adds a generic cpufreq driver for CPU0 frequency management.
--
2.0.0.rc2