From: Mark Rutland <mark.rutland@arm.com>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
rt@linuxtronix.de,
Russell King - ARM Linux <linux@armlinux.org.uk>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
sboyd@codeaurora.org,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 15/20] ARM/hw_breakpoint: Convert to hotplug state machine
Date: Wed, 4 Jan 2017 13:56:44 +0000 [thread overview]
Message-ID: <20170104135644.GA29212@leverpostej> (raw)
In-Reply-To: <20170103093335.GA5605@leverpostej>
On Tue, Jan 03, 2017 at 09:33:36AM +0000, Mark Rutland wrote:
> Hi,
>
> On Mon, Jan 02, 2017 at 09:15:29PM +0100, Linus Walleij wrote:
> > On Mon, Jan 2, 2017 at 4:00 PM, Russell King - ARM Linux
> > <linux@armlinux.org.uk> wrote:
> > > On Mon, Jan 02, 2017 at 03:34:32PM +0100, Linus Walleij wrote:
> > >> in the first line of arch_hw_breakpoint_init() in
> > >> arch/arm/kernel/hw_breakpoint.c
> > >>
> > >> I suspect that is not an accepable solution ...
> > >>
> > >> It hangs at PC is at write_wb_reg+0x20c/0x330
> > >> Which is c03101dc, and looks like this in objdump -d:
> > >>
> > >> c031020c: ee001eba mcr 14, 0, r1, cr0, cr10, {5}
> > >> c0310210: eaffffb3 b c03100e4 <write_wb_reg+0x114>
> > >
> > > ... and this is several instructions after the address you mention above.
> > > Presumably c03101dc is accessing a higher numbered register?
> >
> > Ah sorry. It looks like this:
> >
> > c03101dc: ee001ed0 mcr 14, 0, r1, cr0, cr0, {6}
> > c03101e0: eaffffbf b c03100e4 <write_wb_reg+0x114>
> > c03101e4: ee001ebf mcr 14, 0, r1, cr0, cr15, {5}
> > c03101e8: eaffffbd b c03100e4 <write_wb_reg+0x114>
> > c03101ec: ee001ebe mcr 14, 0, r1, cr0, cr14, {5}
> > c03101f0: eaffffbb b c03100e4 <write_wb_reg+0x114>
> > c03101f4: ee001ebd mcr 14, 0, r1, cr0, cr13, {5}
> > c03101f8: eaffffb9 b c03100e4 <write_wb_reg+0x114>
>
> FWIW, I was tracking an issue in this area before the holiday.
>
> It looked like DBGPRSR.SPD is set unexpectedly over the default idle
> path (i.e. WFI), causing the (otherwise valid) register accesses above
> to be handled as undefined.
>
> I haven't looked at the patch in detail, but I guess that it allows idle
> to occur between reset_ctrl_regs() and arch_hw_breakpoint_init().
I've just reproduced this locally on my dragonboard APQ8060.
It looks like the write_wb_reg() call that's exploding is from
get_max_wp_len(), which we call immediately after registering the
dbg_reset_online callback. Clearing DBGPRSR.SPD before the write_wb_reg() hides
the problem, so I suspect we're seeing the issue I mentioned above -- it just
so happens that we go idle in a new place.
The below hack allows boot to continue, but is not a real fix. I'm not
immediately sure what to do.
Linus, I wasn't able to get ethernet working. Do I need anything on top
of v4.10-rc2 && multi_v7_defconfig?
Thanks,
Mark.
---->8----
diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index 188180b..a0982ab 100644
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -302,7 +302,7 @@ int hw_breakpoint_slots(int type)
*/
static u8 get_max_wp_len(void)
{
- u32 ctrl_reg;
+ u32 ctrl_reg, val;
struct arch_hw_breakpoint_ctrl ctrl;
u8 size = 4;
@@ -313,6 +313,9 @@ static u8 get_max_wp_len(void)
ctrl.len = ARM_BREAKPOINT_LEN_8;
ctrl_reg = encode_ctrl_reg(ctrl);
+ /* HACK: CLEAR SPD */
+ ARM_DBG_READ(c1, c5, 4, val);
+
write_wb_reg(ARM_BASE_WVR, 0);
write_wb_reg(ARM_BASE_WCR, ctrl_reg);
if ((read_wb_reg(ARM_BASE_WCR) & ctrl_reg) == ctrl_reg)
next prev parent reply other threads:[~2017-01-04 13:57 UTC|newest]
Thread overview: 94+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-17 18:35 cpu hotplug: convert more drivers (batch #5) Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 01/20] x86/mce/therm_throt: Convert to hotplug state machine Sebastian Andrzej Siewior
2016-11-21 15:46 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:39 ` tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 02/20] x86/cpuid: " Sebastian Andrzej Siewior
2016-11-21 15:47 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:40 ` tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 03/20] x86/msr: " Sebastian Andrzej Siewior
2016-11-21 15:48 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:41 ` tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 04/20] hwmon/coretemp: " Sebastian Andrzej Siewior
2016-11-20 22:30 ` [04/20] " Guenter Roeck
2016-11-21 22:35 ` Sebastian Andrzej Siewior
2016-11-21 15:56 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-21 21:32 ` Guenter Roeck
2016-11-21 21:53 ` Thomas Gleixner
2016-11-17 18:35 ` [PATCH 05/20] hwmon/via-cputemp: Remove pointless CPU check on each CPU Sebastian Andrzej Siewior
2016-11-19 17:23 ` [05/20] " Guenter Roeck
2016-11-19 22:53 ` Sebastian Andrzej Siewior
2016-11-20 3:53 ` Guenter Roeck
2016-11-20 20:34 ` Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 06/20] hwmon/via-cputemp: Convert to hotplug state machine Sebastian Andrzej Siewior
2016-11-18 15:09 ` [PATCH 06/20 v2] " Sebastian Andrzej Siewior
2016-11-23 15:29 ` [PATCH 06/20] " Guenter Roeck
2016-12-09 11:53 ` Thomas Gleixner
2016-12-09 18:17 ` Guenter Roeck
2016-12-09 18:27 ` Thomas Gleixner
2016-11-17 18:35 ` [PATCH 07/20] pci/xgene-msi: " Sebastian Andrzej Siewior
2016-11-21 15:48 ` [tip:smp/hotplug] PCI/xgene-msi: " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:42 ` tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 08/20] powercap/intel_rapl: Add missing domain data update on hotplug Sebastian Andrzej Siewior
2016-11-21 15:49 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner
2016-11-17 18:35 ` [PATCH 09/20] powercap/intel rapl: Convert to hotplug state machine Sebastian Andrzej Siewior
2016-11-21 15:49 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 10/20] powercap/intel_rapl: Cleanup duplicated init code Sebastian Andrzej Siewior
2016-11-21 15:50 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner
2016-11-17 18:35 ` [PATCH 11/20] watchdog/octeon: Convert to hotplug state machine Sebastian Andrzej Siewior
2016-11-21 15:50 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:43 ` tip-bot for Sebastian Andrzej Siewior
2016-11-24 16:10 ` [11/20] " Guenter Roeck
2016-11-17 18:35 ` [PATCH 12/20] net/iucv: " Sebastian Andrzej Siewior
2016-11-21 15:51 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:43 ` tip-bot for Sebastian Andrzej Siewior
2016-11-23 18:04 ` [PATCH 12/20] " Ursula Braun
2016-11-24 9:10 ` Sebastian Andrzej Siewior
2016-11-24 14:14 ` [PATCH 12/20 v2] " Sebastian Andrzej Siewior
2016-11-24 16:10 ` [PATCH] net/iucv: use explicit clean up labels in iucv_init() Sebastian Andrzej Siewior
2016-11-24 19:57 ` [tip:smp/hotplug] net/iucv: Use " tip-bot for Sebastian Andrzej Siewior
2016-11-28 16:24 ` [PATCH] net/iucv: use " David Miller
2016-11-28 16:31 ` Thomas Gleixner
2016-11-28 16:37 ` [tip:smp/hotplug] net/iucv: Use " tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 13/20] sched/nohz: Convert to hotplug state machine Sebastian Andrzej Siewior
2016-11-21 15:51 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:44 ` tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 14/20] arm/bL_switcher: " Sebastian Andrzej Siewior
2016-11-21 15:52 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:44 ` tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 15/20] ARM/hw_breakpoint: " Sebastian Andrzej Siewior
2016-11-18 12:04 ` Will Deacon
2016-11-18 13:11 ` Thomas Gleixner
2016-11-18 13:29 ` Will Deacon
2016-11-18 13:42 ` Thomas Gleixner
2016-11-18 13:48 ` Will Deacon
2016-11-18 13:59 ` Thomas Gleixner
2016-11-18 14:11 ` Will Deacon
2016-11-21 15:52 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:45 ` tip-bot for Sebastian Andrzej Siewior
2017-01-02 14:15 ` [PATCH 15/20] " Linus Walleij
2017-01-02 14:34 ` Linus Walleij
2017-01-02 15:00 ` Russell King - ARM Linux
2017-01-02 20:15 ` Linus Walleij
2017-01-03 9:33 ` Mark Rutland
2017-01-04 11:27 ` Sebastian Andrzej Siewior
2017-01-04 13:56 ` Mark Rutland [this message]
2017-01-04 14:32 ` Will Deacon
2017-01-05 15:57 ` Mark Rutland
2017-01-05 15:26 ` Linus Walleij
2017-01-05 17:14 ` Mark Rutland
2016-11-17 18:35 ` [PATCH 16/20] powerpc/sysfs: " Sebastian Andrzej Siewior
2016-11-21 15:53 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:45 ` tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 17/20] sparc/sysfs: " Sebastian Andrzej Siewior
2016-11-17 18:39 ` David Miller
2016-11-21 15:54 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:46 ` tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 18/20] x86/oprofile/nmi: Remove superfluous smp_function_call_single() Sebastian Andrzej Siewior
2016-11-21 15:54 ` [tip:smp/hotplug] " tip-bot for Anna-Maria Gleixner
2016-11-22 22:46 ` tip-bot for Anna-Maria Gleixner
2016-11-17 18:35 ` [PATCH 19/20] x86/oprofile/nmi: Convert to hotplug state machine Sebastian Andrzej Siewior
2016-11-21 15:55 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:47 ` tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 20/20] x86/pci/amd-bus: " Sebastian Andrzej Siewior
2016-11-21 15:55 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:47 ` tip-bot for Sebastian Andrzej Siewior
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