* [PATCH v2 1/2] ARM: tegra: Fix FLOW_CTLR_HALT register clobbering by tegra_resume()
2019-07-30 17:23 [PATCH v2 0/2] Tegra30+ CPU suspend-resume bug-fixes Dmitry Osipenko
@ 2019-07-30 17:23 ` Dmitry Osipenko
2019-07-30 17:23 ` [PATCH v2 2/2] ARM: tegra: Use WFE for power-gating on Tegra30 Dmitry Osipenko
2019-10-29 13:33 ` [PATCH v2 0/2] Tegra30+ CPU suspend-resume bug-fixes Thierry Reding
2 siblings, 0 replies; 5+ messages in thread
From: Dmitry Osipenko @ 2019-07-30 17:23 UTC (permalink / raw)
To: Thierry Reding, Jonathan Hunter, Peter De Schrijver
Cc: linux-tegra, linux-kernel
There is an unfortunate typo in the code that results in writing to
FLOW_CTLR_HALT instead of FLOW_CTLR_CSR.
Cc: <stable@vger.kernel.org>
Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
arch/arm/mach-tegra/reset-handler.S | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm/mach-tegra/reset-handler.S b/arch/arm/mach-tegra/reset-handler.S
index df44828a34d3..53123ae4ac3b 100644
--- a/arch/arm/mach-tegra/reset-handler.S
+++ b/arch/arm/mach-tegra/reset-handler.S
@@ -44,16 +44,16 @@ ENTRY(tegra_resume)
cmp r6, #TEGRA20
beq 1f @ Yes
/* Clear the flow controller flags for this CPU. */
- cpu_to_csr_reg r1, r0
+ cpu_to_csr_reg r3, r0
mov32 r2, TEGRA_FLOW_CTRL_BASE
- ldr r1, [r2, r1]
+ ldr r1, [r2, r3]
/* Clear event & intr flag */
orr r1, r1, \
#FLOW_CTRL_CSR_INTR_FLAG | FLOW_CTRL_CSR_EVENT_FLAG
movw r0, #0x3FFD @ enable, cluster_switch, immed, bitmaps
@ & ext flags for CPU power mgnt
bic r1, r1, r0
- str r1, [r2]
+ str r1, [r2, r3]
1:
mov32 r9, 0xc09
--
2.22.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v2 2/2] ARM: tegra: Use WFE for power-gating on Tegra30
2019-07-30 17:23 [PATCH v2 0/2] Tegra30+ CPU suspend-resume bug-fixes Dmitry Osipenko
2019-07-30 17:23 ` [PATCH v2 1/2] ARM: tegra: Fix FLOW_CTLR_HALT register clobbering by tegra_resume() Dmitry Osipenko
@ 2019-07-30 17:23 ` Dmitry Osipenko
2019-10-05 15:12 ` Peter Geis
2019-10-29 13:33 ` [PATCH v2 0/2] Tegra30+ CPU suspend-resume bug-fixes Thierry Reding
2 siblings, 1 reply; 5+ messages in thread
From: Dmitry Osipenko @ 2019-07-30 17:23 UTC (permalink / raw)
To: Thierry Reding, Jonathan Hunter, Peter De Schrijver
Cc: linux-tegra, linux-kernel
Turned out that WFI doesn't work reliably on Tegra30 as a trigger for
the power-gating, it causes CPU hang under some circumstances like having
memory controller running of PLLP. The TRM doc states that WFI should be
used for the Big-Little "Cluster Switch", while WFE for the power-gating.
Hence let's use the WFE for CPU0 power-gating, like it is done for the
power-gating of a secondary cores. This fixes CPU hang after entering LP2
with memory running off PLLP.
Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
arch/arm/mach-tegra/sleep-tegra30.S | 4 +++-
drivers/soc/tegra/flowctrl.c | 19 +++++++++++++++++--
2 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/arch/arm/mach-tegra/sleep-tegra30.S b/arch/arm/mach-tegra/sleep-tegra30.S
index 6c28395d8c75..17f7a2a6a494 100644
--- a/arch/arm/mach-tegra/sleep-tegra30.S
+++ b/arch/arm/mach-tegra/sleep-tegra30.S
@@ -683,10 +683,12 @@ tegra30_enter_sleep:
dsb
ldr r0, [r6, r2] /* memory barrier */
+ cmp r10, #TEGRA30
halted:
isb
dsb
- wfi /* CPU should be power gated here */
+ wfine /* CPU should be power gated here */
+ wfeeq
/* !!!FIXME!!! Implement halt failure handler */
b halted
diff --git a/drivers/soc/tegra/flowctrl.c b/drivers/soc/tegra/flowctrl.c
index b6bdeef33db1..eb96a3086d6d 100644
--- a/drivers/soc/tegra/flowctrl.c
+++ b/drivers/soc/tegra/flowctrl.c
@@ -91,8 +91,23 @@ void flowctrl_cpu_suspend_enter(unsigned int cpuid)
reg &= ~TEGRA30_FLOW_CTRL_CSR_WFE_BITMAP;
/* clear wfi bitmap */
reg &= ~TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP;
- /* pwr gating on wfi */
- reg |= TEGRA30_FLOW_CTRL_CSR_WFI_CPU0 << cpuid;
+
+ if (tegra_get_chip_id() == TEGRA30) {
+ /*
+ * The wfi doesn't work well on Tegra30 because
+ * CPU hangs under some odd circumstances after
+ * power-gating (like memory running off PLLP),
+ * hence use wfe that is working perfectly fine.
+ * Note that Tegra30 TRM doc clearly stands that
+ * wfi should be used for the "Cluster Switching",
+ * while wfe for the power-gating, just like it
+ * is done on Tegra20.
+ */
+ reg |= TEGRA20_FLOW_CTRL_CSR_WFE_CPU0 << cpuid;
+ } else {
+ /* pwr gating on wfi */
+ reg |= TEGRA30_FLOW_CTRL_CSR_WFI_CPU0 << cpuid;
+ }
break;
}
reg |= FLOW_CTRL_CSR_INTR_FLAG; /* clear intr flag */
--
2.22.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH v2 2/2] ARM: tegra: Use WFE for power-gating on Tegra30
2019-07-30 17:23 ` [PATCH v2 2/2] ARM: tegra: Use WFE for power-gating on Tegra30 Dmitry Osipenko
@ 2019-10-05 15:12 ` Peter Geis
0 siblings, 0 replies; 5+ messages in thread
From: Peter Geis @ 2019-10-05 15:12 UTC (permalink / raw)
To: Dmitry Osipenko
Cc: Thierry Reding, Jonathan Hunter, Peter De Schrijver, linux-tegra,
linux-kernel
The Ouya (tegra30) hard locks when the emc clock drops below 400mhz.
Discovered while testing the devfreq and emc drivers.
This patch resolves that issue.
Tested-by: Peter Geis <pgwipeout@gmail.com>
On Tue, Jul 30, 2019 at 2:10 PM Dmitry Osipenko <digetx@gmail.com> wrote:
>
> Turned out that WFI doesn't work reliably on Tegra30 as a trigger for
> the power-gating, it causes CPU hang under some circumstances like having
> memory controller running of PLLP. The TRM doc states that WFI should be
> used for the Big-Little "Cluster Switch", while WFE for the power-gating.
> Hence let's use the WFE for CPU0 power-gating, like it is done for the
> power-gating of a secondary cores. This fixes CPU hang after entering LP2
> with memory running off PLLP.
>
> Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
> arch/arm/mach-tegra/sleep-tegra30.S | 4 +++-
> drivers/soc/tegra/flowctrl.c | 19 +++++++++++++++++--
> 2 files changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm/mach-tegra/sleep-tegra30.S b/arch/arm/mach-tegra/sleep-tegra30.S
> index 6c28395d8c75..17f7a2a6a494 100644
> --- a/arch/arm/mach-tegra/sleep-tegra30.S
> +++ b/arch/arm/mach-tegra/sleep-tegra30.S
> @@ -683,10 +683,12 @@ tegra30_enter_sleep:
> dsb
> ldr r0, [r6, r2] /* memory barrier */
>
> + cmp r10, #TEGRA30
> halted:
> isb
> dsb
> - wfi /* CPU should be power gated here */
> + wfine /* CPU should be power gated here */
> + wfeeq
>
> /* !!!FIXME!!! Implement halt failure handler */
> b halted
> diff --git a/drivers/soc/tegra/flowctrl.c b/drivers/soc/tegra/flowctrl.c
> index b6bdeef33db1..eb96a3086d6d 100644
> --- a/drivers/soc/tegra/flowctrl.c
> +++ b/drivers/soc/tegra/flowctrl.c
> @@ -91,8 +91,23 @@ void flowctrl_cpu_suspend_enter(unsigned int cpuid)
> reg &= ~TEGRA30_FLOW_CTRL_CSR_WFE_BITMAP;
> /* clear wfi bitmap */
> reg &= ~TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP;
> - /* pwr gating on wfi */
> - reg |= TEGRA30_FLOW_CTRL_CSR_WFI_CPU0 << cpuid;
> +
> + if (tegra_get_chip_id() == TEGRA30) {
> + /*
> + * The wfi doesn't work well on Tegra30 because
> + * CPU hangs under some odd circumstances after
> + * power-gating (like memory running off PLLP),
> + * hence use wfe that is working perfectly fine.
> + * Note that Tegra30 TRM doc clearly stands that
> + * wfi should be used for the "Cluster Switching",
> + * while wfe for the power-gating, just like it
> + * is done on Tegra20.
> + */
> + reg |= TEGRA20_FLOW_CTRL_CSR_WFE_CPU0 << cpuid;
> + } else {
> + /* pwr gating on wfi */
> + reg |= TEGRA30_FLOW_CTRL_CSR_WFI_CPU0 << cpuid;
> + }
> break;
> }
> reg |= FLOW_CTRL_CSR_INTR_FLAG; /* clear intr flag */
> --
> 2.22.0
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2 0/2] Tegra30+ CPU suspend-resume bug-fixes
2019-07-30 17:23 [PATCH v2 0/2] Tegra30+ CPU suspend-resume bug-fixes Dmitry Osipenko
2019-07-30 17:23 ` [PATCH v2 1/2] ARM: tegra: Fix FLOW_CTLR_HALT register clobbering by tegra_resume() Dmitry Osipenko
2019-07-30 17:23 ` [PATCH v2 2/2] ARM: tegra: Use WFE for power-gating on Tegra30 Dmitry Osipenko
@ 2019-10-29 13:33 ` Thierry Reding
2 siblings, 0 replies; 5+ messages in thread
From: Thierry Reding @ 2019-10-29 13:33 UTC (permalink / raw)
To: Dmitry Osipenko
Cc: Jonathan Hunter, Peter De Schrijver, linux-tegra, linux-kernel
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On Tue, Jul 30, 2019 at 08:23:38PM +0300, Dmitry Osipenko wrote:
> Hello,
>
> This small series addresses two suspend-resume bugs: one affects Tegra30+
> due to a typo in the code, other fixes CPU hang on Tegra30 specifically.
>
> Changelog:
>
> v2: Reworded comment to the code to make it sound better in the patch
> "Use WFE for power-gating on Tegra30".
>
> Dmitry Osipenko (2):
> ARM: tegra: Fix FLOW_CTLR_HALT register clobbering by tegra_resume()
> ARM: tegra: Use WFE for power-gating on Tegra30
Applied to for-5.5/arm/core, thanks.
Thierry
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^ permalink raw reply [flat|nested] 5+ messages in thread