From: Sowjanya Komatineni <skomatineni@nvidia.com>
To: Dmitry Osipenko <digetx@gmail.com>, Marc Zyngier <marc.zyngier@arm.com>
Cc: thierry.reding@gmail.com, jonathanh@nvidia.com,
tglx@linutronix.de, jason@lakedaemon.net,
linus.walleij@linaro.org, stefan@agner.ch, mark.rutland@arm.com,
pdeschrijver@nvidia.com, pgaikwad@nvidia.com, sboyd@kernel.org,
linux-clk@vger.kernel.org, linux-gpio@vger.kernel.org,
jckuo@nvidia.com, josephl@nvidia.com, talho@nvidia.com,
linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org,
mperttunen@nvidia.com, spatra@nvidia.com, robh+dt@kernel.org,
devicetree@vger.kernel.org
Subject: Re: [PATCH V6 01/21] irqchip: tegra: Do not disable COP IRQ during suspend
Date: Wed, 24 Jul 2019 16:09:53 -0700 [thread overview]
Message-ID: <78d5af07-2556-b60d-01d7-3684ebe7040b@nvidia.com> (raw)
In-Reply-To: <8e9f821c-3717-510d-c64f-8a1cc2452c25@gmail.com>
On 7/22/19 4:35 PM, Dmitry Osipenko wrote:
> 22.07.2019 21:38, Marc Zyngier пишет:
>> On Mon, 22 Jul 2019 09:21:21 -0700
>> Sowjanya Komatineni <skomatineni@nvidia.com> wrote:
>>
>>> On 7/22/19 3:57 AM, Dmitry Osipenko wrote:
>>>> 22.07.2019 13:13, Marc Zyngier пишет:
>>>>> On 22/07/2019 10:54, Dmitry Osipenko wrote:
>>>>>> 21.07.2019 22:40, Sowjanya Komatineni пишет:
>>>>>>> Tegra210 platforms use sc7 entry firmware to program Tegra LP0/SC7 entry
>>>>>>> sequence and sc7 entry firmware is run from COP/BPMP-Lite.
>>>>>>>
>>>>>>> So, COP/BPMP-Lite still need IRQ function to finish SC7 suspend sequence
>>>>>>> for Tegra210.
>>>>>>>
>>>>>>> This patch has fix for leaving the COP IRQ enabled for Tegra210 during
>>>>>>> interrupt controller suspend operation.
>>>>>>>
>>>>>>> Acked-by: Thierry Reding <treding@nvidia.com>
>>>>>>> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
>>>>>>> ---
>>>>>>> drivers/irqchip/irq-tegra.c | 20 ++++++++++++++++++--
>>>>>>> 1 file changed, 18 insertions(+), 2 deletions(-)
>>>>>>>
>>>>>>> diff --git a/drivers/irqchip/irq-tegra.c b/drivers/irqchip/irq-tegra.c
>>>>>>> index e1f771c72fc4..851f88cef508 100644
>>>>>>> --- a/drivers/irqchip/irq-tegra.c
>>>>>>> +++ b/drivers/irqchip/irq-tegra.c
>>>>>>> @@ -44,6 +44,7 @@ static unsigned int num_ictlrs;
>>>>>>>
>>>>>>> struct tegra_ictlr_soc {
>>>>>>> unsigned int num_ictlrs;
>>>>>>> + bool supports_sc7;
>>>>>>> };
>>>>>>>
>>>>>>> static const struct tegra_ictlr_soc tegra20_ictlr_soc = {
>>>>>>> @@ -56,6 +57,7 @@ static const struct tegra_ictlr_soc tegra30_ictlr_soc = {
>>>>>>>
>>>>>>> static const struct tegra_ictlr_soc tegra210_ictlr_soc = {
>>>>>>> .num_ictlrs = 6,
>>>>>>> + .supports_sc7 = true,
>>>>>>> };
>>>>>>>
>>>>>>> static const struct of_device_id ictlr_matches[] = {
>>>>>>> @@ -67,6 +69,7 @@ static const struct of_device_id ictlr_matches[] = {
>>>>>>>
>>>>>>> struct tegra_ictlr_info {
>>>>>>> void __iomem *base[TEGRA_MAX_NUM_ICTLRS];
>>>>>>> + const struct tegra_ictlr_soc *soc;
>>>>>>> #ifdef CONFIG_PM_SLEEP
>>>>>>> u32 cop_ier[TEGRA_MAX_NUM_ICTLRS];
>>>>>>> u32 cop_iep[TEGRA_MAX_NUM_ICTLRS];
>>>>>>> @@ -147,8 +150,20 @@ static int tegra_ictlr_suspend(void)
>>>>>>> lic->cop_ier[i] = readl_relaxed(ictlr + ICTLR_COP_IER);
>>>>>>> lic->cop_iep[i] = readl_relaxed(ictlr + ICTLR_COP_IEP_CLASS);
>>>>>>>
>>>>>>> - /* Disable COP interrupts */
>>>>>>> - writel_relaxed(~0ul, ictlr + ICTLR_COP_IER_CLR);
>>>>>>> + /*
>>>>>>> + * AVP/COP/BPMP-Lite is the Tegra boot processor.
>>>>>>> + *
>>>>>>> + * Tegra210 system suspend flow uses sc7entry firmware which
>>>>>>> + * is executed by COP/BPMP and it includes disabling COP IRQ,
>>>>>>> + * clamping CPU rail, turning off VDD_CPU, and preparing the
>>>>>>> + * system to go to SC7/LP0.
>>>>>>> + *
>>>>>>> + * COP/BPMP wakes up when COP IRQ is triggered and runs
>>>>>>> + * sc7entry-firmware. So need to keep COP interrupt enabled.
>>>>>>> + */
>>>>>>> + if (!lic->soc->supports_sc7)
>>>>>>> + /* Disable COP interrupts if SC7 is not supported */
>>>>>> All Tegra SoCs support SC7, hence the 'supports_sc7' and the comment
>>>>>> doesn't sound correct to me. Something like 'firmware_sc7' should suit
>>>>>> better here.
>>>>> If what you're saying is true, then the whole patch is wrong, and the
>>>>> SC7 property should come from DT.
>>>> It should be safe to assume that all of existing Tegra210 devices use
>>>> the firmware for SC7, hence I wouldn't say that the patch is entirely
>>>> wrong. To me it's not entirely correct.
>>> Yes, all existing Tegra210 platforms uses sc7 entry firmware for SC7 and
>>> AVP/COP IRQ need to be kept enabled as during suspend ATF triggers IRQ
>>> to COP for SC7 entry fw execution.
> Okay, as I already wrote before, it looks to me that a more proper
> solution should be to just remove everything related to COP from this
> driver instead of adding custom quirks for T210.
>
> The disabling / restoring of COP interrupts should be relevant only for
> the multimedia firmware on older Tegra SoCs. That firmware won't be ever
> supported in the upstream simply because NVIDIA abandoned the support
> for older hardware in the downstream and because it is not possible due
> to some legal weirdness (IIUC). The only variant for upstream is
> reverse-engineering of hardware (not the firmware BLOB) and writing
> proper opensource drivers for the upstream kernel, which we're already
> doing and have success to a some extent.
>
>> That's not the question. Dmitry says that the SC7 support is not a
>> property of the SoC, but mostly a platform decision on whether the
>> firmware supports SC7 or not.
>>
>> To me, that's a clear indication that this should not be hardcoded in
>> the driver, but instead obtained dynamically, via DT or otherwise.
> We already have an nvidia,suspend-mode property in the device-tree of
> the Power Management Controller node (all Tegra SoCs) which defines what
> suspending type is supported by a particular board.
>
>>>>>>> + writel_relaxed(~0ul, ictlr + ICTLR_COP_IER_CLR);
>>>>>> Secondly, I'm also not sure why COP interrupts need to be disabled for
>>>>>> pre-T210 at all, since COP is unused. This looks to me like it was
>>>>>> cut-n-pasted from downstream kernel without a good reason and could be
>>>>>> simply removed.
>>>>> Please verify that this is actually the case. Tegra-2 definitely needed
>>>>> some level of poking, and I'm not keen on changing anything there until
>>>>> you (or someone else) has verified it on actual HW (see e307cc8941fc).
>>>> Tested on Tegra20 and Tegra30, LP1 suspend-resume works perfectly fine
>>>> with all COP bits removed from the driver.
>>>>
>>>> AFAIK, the reason why downstream needed that disabling is that it uses
>>>> proprietary firmware which is running on the COP and that firmware is
>>>> usually a BLOB audio/video DEC-ENC driver which doesn't cleanup
>>>> interrupts after itself. That firmware is not applicable for the
>>>> upstream kernel, hence there is no need to care about it.
>>>>
>>>>> Joseph, can you please shed some light here?
>>> SC7 entry flow uses 3rd party ATF (arm-trusted FW) blob which is the
>>> one that actually loads SC7 entry firmware and triggers IRQ to
>>> AVP/COP which causes COP to wakeup and run SC7 entry FW.
>>>
>>> So when SC7 support is enabled, IRQ need to be kept enabled and when
>>> SC7 FW starts execution, it will disable COP IRQ.
>> This looks like a lot of undocumented assumptions on what firmware
>> does, as well as what firmware *is*. What I gather from this thread is
>> that there is at least two versions of firmware (a "proprietary
>> firmware" for "downstream kernels", and another one for mainline), and
>> that they do different things.
>>
>> Given that we cannot know what people actually run, I don't think we
>> can safely remove anything unless this gets tested on the full spectrum
>> of HW/FW combination.
> I'm not sure whether multiple firmware variations exist in the wild for
> Tegra210. Maybe Sowjanya or somebody else from NVIDIA could clarify. I
> think there should be some efforts in regards to a fully opensource
> firmware on Tegra210, but I'm not following it and have no idea about
> the status.
>
> You're right that there are multiple variants of suspend-resuming flow
> on Tegra SoCs. The older 32bit Tegra SoC generations have a variety of
> options in regards to suspend-resuming, including firmware-less variants
> on platforms that are having kernel running in secure mode (dev boards,
> most of Tegra20 consumer devices) and Trusted-Foundations firmware
> variant for insecure platforms (consumer devices). And yes, vendor
> firmware creates a lot of headache in regards to bringing support into
> upstream because it usually does a lot of odd undocumented things which
> may also vary depending on a firmware version (bootloader, etc) and it
> also usually difficult to replace it with an opensource alternative due
> to a crypto signing.
Tried without this patch which keeps COP IRQ disabled and I see SC7
entry FW execution happens still.
Digging through the ATF FW code, I see on SC7 entry firmware loading
into IRAM, COP processor is reset with RESET VECTOR set to SC7 entry
firmware location in IRAM and on reset de-assert & unhalt COP, SC7
firmware starts execution.
Will remove this patch in next version...
next prev parent reply other threads:[~2019-07-24 23:09 UTC|newest]
Thread overview: 85+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-21 19:40 [PATCH V6 00/21] SC7 entry and exit support for Tegra210 Sowjanya Komatineni
2019-07-21 19:40 ` [PATCH V6 01/21] irqchip: tegra: Do not disable COP IRQ during suspend Sowjanya Komatineni
2019-07-21 20:24 ` Marc Zyngier
2019-07-22 9:54 ` Dmitry Osipenko
2019-07-22 10:13 ` Marc Zyngier
2019-07-22 10:57 ` Dmitry Osipenko
2019-07-22 16:21 ` Sowjanya Komatineni
2019-07-22 18:38 ` Marc Zyngier
2019-07-22 23:35 ` Dmitry Osipenko
2019-07-24 23:09 ` Sowjanya Komatineni [this message]
2019-07-26 4:48 ` Dmitry Osipenko
2019-07-25 9:55 ` Peter De Schrijver
2019-07-25 10:05 ` Dmitry Osipenko
2019-07-25 10:33 ` Peter De Schrijver
2019-07-25 10:38 ` Peter De Schrijver
2019-07-25 10:59 ` Dmitry Osipenko
2019-08-02 13:05 ` Peter De Schrijver
2019-08-02 17:35 ` Dmitry Osipenko
2019-07-21 19:40 ` [PATCH V6 02/21] pinctrl: tegra: Add suspend and resume support Sowjanya Komatineni
2019-07-21 22:03 ` Dmitry Osipenko
2019-07-21 22:09 ` Dmitry Osipenko
2019-07-21 22:48 ` Sowjanya Komatineni
2019-07-21 19:40 ` [PATCH V6 03/21] pinctrl: tegra210: Add Tegra210 pinctrl pm ops Sowjanya Komatineni
2019-07-21 19:40 ` [PATCH V6 04/21] clk: tegra: Save and restore divider rate Sowjanya Komatineni
2019-07-21 22:14 ` Dmitry Osipenko
2019-07-21 19:40 ` [PATCH V6 05/21] clk: tegra: pllout: Save and restore pllout context Sowjanya Komatineni
2019-07-21 22:18 ` Dmitry Osipenko
2019-07-21 19:40 ` [PATCH V6 06/21] clk: tegra: pll: Save and restore pll context Sowjanya Komatineni
2019-07-21 21:44 ` Dmitry Osipenko
2019-07-21 22:47 ` Sowjanya Komatineni
2019-07-21 22:21 ` Dmitry Osipenko
2019-07-22 3:22 ` Sowjanya Komatineni
2019-07-21 19:40 ` [PATCH V6 07/21] clk: tegra: Support for OSC context save and restore Sowjanya Komatineni
2019-07-22 10:12 ` Dmitry Osipenko
2019-07-21 19:40 ` [PATCH V6 08/21] clk: tegra: clk-periph: Add save and restore support Sowjanya Komatineni
2019-07-21 19:40 ` [PATCH V6 09/21] clk: tegra: clk-super: Fix to enable PLLP branches to CPU Sowjanya Komatineni
2019-07-21 21:16 ` Dmitry Osipenko
2019-07-21 22:39 ` Sowjanya Komatineni
2019-07-22 3:17 ` Sowjanya Komatineni
2019-07-22 6:32 ` Dmitry Osipenko
2019-07-22 7:12 ` Sowjanya Komatineni
2019-07-22 7:17 ` Dmitry Osipenko
2019-07-22 7:24 ` Sowjanya Komatineni
2019-07-22 7:30 ` Dmitry Osipenko
2019-07-22 7:36 ` Sowjanya Komatineni
2019-07-21 19:40 ` [PATCH V6 10/21] clk: tegra: clk-super: Add save and restore support Sowjanya Komatineni
2019-07-21 19:40 ` [PATCH V6 11/21] clk: tegra: clk-dfll: Add suspend and resume support Sowjanya Komatineni
2019-07-21 21:32 ` Dmitry Osipenko
2019-07-21 22:42 ` Sowjanya Komatineni
2019-07-21 19:40 ` [PATCH V6 12/21] cpufreq: tegra124: " Sowjanya Komatineni
2019-07-21 21:04 ` Dmitry Osipenko
2019-07-21 19:40 ` [PATCH V6 13/21] clk: tegra210: Use fence_udelay during PLLU init Sowjanya Komatineni
2019-07-21 19:40 ` [PATCH V6 14/21] clk: tegra210: Add suspend and resume support Sowjanya Komatineni
2019-07-21 21:38 ` Dmitry Osipenko
2019-07-21 22:45 ` Sowjanya Komatineni
2019-07-22 6:10 ` Dmitry Osipenko
2019-07-22 6:52 ` Sowjanya Komatineni
2019-07-22 7:09 ` Dmitry Osipenko
2019-07-22 7:12 ` Dmitry Osipenko
2019-08-02 17:51 ` Stephen Boyd
2019-08-02 20:39 ` Sowjanya Komatineni
2019-08-07 21:22 ` Stephen Boyd
2019-07-21 19:40 ` [PATCH V6 15/21] soc/tegra: pmc: Allow to support more tegras wake Sowjanya Komatineni
2019-07-21 19:40 ` [PATCH V6 16/21] soc/tegra: pmc: Add pmc wake support for tegra210 Sowjanya Komatineni
2019-07-23 0:58 ` Dmitry Osipenko
2019-07-23 1:08 ` Dmitry Osipenko
2019-07-23 1:41 ` Dmitry Osipenko
2019-07-23 1:52 ` Sowjanya Komatineni
2019-07-23 3:03 ` Dmitry Osipenko
2019-07-23 3:09 ` Sowjanya Komatineni
2019-07-23 3:25 ` Dmitry Osipenko
2019-07-23 3:31 ` Sowjanya Komatineni
2019-07-23 3:43 ` Dmitry Osipenko
2019-07-23 14:27 ` Dmitry Osipenko
2019-07-23 23:39 ` Sowjanya Komatineni
2019-07-24 9:31 ` Dmitry Osipenko
2019-07-23 1:52 ` Dmitry Osipenko
2019-07-23 2:10 ` Dmitry Osipenko
2019-07-21 19:40 ` [PATCH V6 17/21] arm64: tegra: Enable wake from deep sleep on RTC alarm Sowjanya Komatineni
2019-07-26 6:30 ` Dmitry Osipenko
2019-07-21 19:40 ` [PATCH V6 18/21] soc/tegra: pmc: Configure core power request polarity Sowjanya Komatineni
2019-07-21 19:40 ` [PATCH V6 19/21] soc/tegra: pmc: Configure deep sleep control settings Sowjanya Komatineni
2019-07-21 19:40 ` [PATCH V6 20/21] arm64: dts: tegra210-p2180: Jetson TX1 SC7 timings Sowjanya Komatineni
2019-07-21 19:41 ` [PATCH V6 21/21] arm64: dts: tegra210-p3450: Jetson nano " Sowjanya Komatineni
2019-07-21 22:25 ` Dmitry Osipenko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=78d5af07-2556-b60d-01d7-3684ebe7040b@nvidia.com \
--to=skomatineni@nvidia.com \
--cc=devicetree@vger.kernel.org \
--cc=digetx@gmail.com \
--cc=jason@lakedaemon.net \
--cc=jckuo@nvidia.com \
--cc=jonathanh@nvidia.com \
--cc=josephl@nvidia.com \
--cc=linus.walleij@linaro.org \
--cc=linux-clk@vger.kernel.org \
--cc=linux-gpio@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tegra@vger.kernel.org \
--cc=marc.zyngier@arm.com \
--cc=mark.rutland@arm.com \
--cc=mperttunen@nvidia.com \
--cc=pdeschrijver@nvidia.com \
--cc=pgaikwad@nvidia.com \
--cc=robh+dt@kernel.org \
--cc=sboyd@kernel.org \
--cc=spatra@nvidia.com \
--cc=stefan@agner.ch \
--cc=talho@nvidia.com \
--cc=tglx@linutronix.de \
--cc=thierry.reding@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).