From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
To: Devi Priya <quic_devipriy@quicinc.com>
Cc: Manivannan Sadhasivam <mani@kernel.org>,
agross@kernel.org, andersson@kernel.org,
konrad.dybcio@linaro.org, lpieralisi@kernel.org, kw@linux.com,
robh@kernel.org, bhelgaas@google.com,
krzysztof.kozlowski+dt@linaro.org, vkoul@kernel.org,
kishon@kernel.org, mturquette@baylibre.com, sboyd@kernel.org,
p.zabel@pengutronix.de, linux-arm-msm@vger.kernel.org,
linux-pci@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-phy@lists.infradead.org,
linux-clk@vger.kernel.org, quic_srichara@quicinc.com,
quic_gokulsri@quicinc.com, quic_sjaganat@quicinc.com,
quic_kathirav@quicinc.com, quic_arajkuma@quicinc.com,
quic_anusha@quicinc.com
Subject: Re: [PATCH 1/7] dt-bindings: PCI: qcom: Add IPQ9574 specific compatible
Date: Tue, 7 Mar 2023 16:56:53 +0200 [thread overview]
Message-ID: <CAA8EJpo-_PXhBnKWD-TWEqY8+uAEjbRsrhJ7XO1PTcYV-MHV9Q@mail.gmail.com> (raw)
In-Reply-To: <2afe8c7e-7e54-460f-7206-64a290beccfb@quicinc.com>
On Tue, 7 Mar 2023 at 16:40, Devi Priya <quic_devipriy@quicinc.com> wrote:
>
>
>
> On 3/7/2023 6:26 PM, Manivannan Sadhasivam wrote:
> > On Tue, Mar 07, 2023 at 03:15:08PM +0530, Devi Priya wrote:
> >>
> >>
> >> On 3/3/2023 11:10 PM, Manivannan Sadhasivam wrote:
> >>> On Fri, Mar 03, 2023 at 05:16:58PM +0200, Dmitry Baryshkov wrote:
> >>>> 28 февраля 2023 г. 08:33:58 GMT+02:00, Manivannan Sadhasivam <mani@kernel.org> пишет:
> >>>>> On Tue, Feb 28, 2023 at 10:56:53AM +0530, Devi Priya wrote:
> >>>>>>
> >>>>>>
> >>>>>> On 2/24/2023 1:53 PM, Manivannan Sadhasivam wrote:
> >>>>>>> On Tue, Feb 14, 2023 at 10:11:29PM +0530, Devi Priya wrote:
> >>>>>>>> Document the compatible for IPQ9574
> >>>>>>>>
> >>>>>> Hi Mani, Thanks for taking time to review the patch.
> >>>>>>>
> >>>>>>> You didn't mention about the "msi-parent" property that is being added
> >>>>>>> by this patch
> >>>>>> Sure, will update the commit message in the next spin
> >>>>>>>
> >>>>>>>> Signed-off-by: Devi Priya <quic_devipriy@quicinc.com>
> >>>>>>>> ---
> >>>>>>>> .../devicetree/bindings/pci/qcom,pcie.yaml | 72 ++++++++++++++++++-
> >>>>>>>> 1 file changed, 70 insertions(+), 2 deletions(-)
> >>>>>>>>
> >>>>>>>> diff --git a/Documentation/devicetree/bindings/pci/qcom,pcie.yaml b/Documentation/devicetree/bindings/pci/qcom,pcie.yaml
> >>>>>>>> index 872817d6d2bd..dabdf2684e2d 100644
> >>>>>>>> --- a/Documentation/devicetree/bindings/pci/qcom,pcie.yaml
> >>>>>>>> +++ b/Documentation/devicetree/bindings/pci/qcom,pcie.yaml
> >>>>>>>> @@ -26,6 +26,7 @@ properties:
> >>>>>>>> - qcom,pcie-ipq8064-v2
> >>>>>>>> - qcom,pcie-ipq8074
> >>>>>>>> - qcom,pcie-ipq8074-gen3
> >>>>>>>> + - qcom,pcie-ipq9574
> >>>>>>>> - qcom,pcie-msm8996
> >>>>>>>> - qcom,pcie-qcs404
> >>>>>>>> - qcom,pcie-sa8540p
> >>>>>>>> @@ -44,11 +45,11 @@ properties:
> >>>>>>>> reg:
> >>>>>>>> minItems: 4
> >>>>>>>> - maxItems: 5
> >>>>>>>> + maxItems: 6
> >>>>>>>> reg-names:
> >>>>>>>> minItems: 4
> >>>>>>>> - maxItems: 5
> >>>>>>>> + maxItems: 6
> >>>>>>>> interrupts:
> >>>>>>>> minItems: 1
> >>>>>>>> @@ -105,6 +106,8 @@ properties:
> >>>>>>>> items:
> >>>>>>>> - const: pciephy
> >>>>>>>> + msi-parent: true
> >>>>>>>> +
> >>>>>>>> power-domains:
> >>>>>>>> maxItems: 1
> >>>>>>>> @@ -173,6 +176,27 @@ allOf:
> >>>>>>>> - const: parf # Qualcomm specific registers
> >>>>>>>> - const: config # PCIe configuration space
> >>>>>>>> + - if:
> >>>>>>>> + properties:
> >>>>>>>> + compatible:
> >>>>>>>> + contains:
> >>>>>>>> + enum:
> >>>>>>>> + - qcom,pcie-ipq9574
> >>>>>>>> + then:
> >>>>>>>> + properties:
> >>>>>>>> + reg:
> >>>>>>>> + minItems: 5
> >>>>>>>> + maxItems: 6
> >>>>>>>> + reg-names:
> >>>>>>>> + minItems: 5
> >>>>>>>> + items:
> >>>>>>>> + - const: dbi # DesignWare PCIe registers
> >>>>>>>> + - const: elbi # External local bus interface registers
> >>>>>>>> + - const: atu # ATU address space
> >>>>>>>> + - const: parf # Qualcomm specific registers
> >>>>>>>> + - const: config # PCIe configuration space
> >>>>>>>> + - const: aggr_noc #PCIe aggr_noc
> >>>>>>>
> >>>>>>> Why do you need this region unlike other SoCs? Is the driver making use of it?
> >>>>>> We have the aggr_noc region in ipq9574 to achieve higher throughput & to
> >>>>>> handle multiple PCIe instances. The driver uses it to rate adapt 1-lane PCIe
> >>>>>> clocks. My bad, missed it. Will add the driver changes in V2.
> >>>>>
> >>>>> Hmm, this is something new. How can you achieve higher throughput with this
> >>>>> region? Can you explain more on how it is used?
> >>>>
> >>>> Based on the name of the region, it looks like it is an interconnect region.
> >>>>
> >>>
> >>> Well, we only have BCM based interconnects so far. That's why I was curious
> >>> about this region and its purpose.
> >> For connected PCIe slave devices that are running at frequency lesser
> >> than the ANOC frequency (342MHz), the rate adapter of ANOC needs to be
> >> configured
> >>>
> >>>> Devi, if this is the case, then you have to handle it through the interconnect driver, rather than poking directly into these registers.
> >>>
> >>> If that so, it doesn't need to be added in this series itself. I believe that
> >>> without aggr_noc region, the PCIe controller can still function properly with
> >>> reduced performance. But you can add the interconnect support later as a
> >>> separate series.
> >> Sure, okay. The ANOC runs at a fixed frequency of 342MHz and the
> >> interconnect clocks are not scaled. The aggr_noc register is just a magic
> >> register for configuring it's rate adapter to ensure no wait cycles are
> >> inserted.
> >>
> >
> > If the purpose of the aggr_noc region is to configure the interconnect clock,
> > then it should be modeled as an interconnect driver.
> Can we use 'syscon' here, as we are not scaling the interconnect
> frequency and this is just a single register write for setting
> the rate adapter?
It should be done outside of the PCIe driver.
It is not "just a single register". It is also setting the anoc/snoc
clocks for USB. And maybe something else, which we haven't seen at
this moment. You are still setting up the NoC, even if the icc
frequency is not scaled.
--
With best wishes
Dmitry
next prev parent reply other threads:[~2023-03-07 15:05 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-14 16:41 [PATCH 0/7] Add PCIe support for IPQ9574 Devi Priya
2023-02-14 16:41 ` [PATCH 1/7] dt-bindings: PCI: qcom: Add IPQ9574 specific compatible Devi Priya
2023-02-16 10:29 ` Krzysztof Kozlowski
2023-02-20 13:29 ` Devi Priya
2023-02-24 8:23 ` Manivannan Sadhasivam
2023-02-28 5:26 ` Devi Priya
2023-02-28 6:33 ` Manivannan Sadhasivam
2023-03-03 15:16 ` Dmitry Baryshkov
2023-03-03 17:40 ` Manivannan Sadhasivam
2023-03-07 9:45 ` Devi Priya
2023-03-07 11:38 ` Dmitry Baryshkov
2023-03-07 12:56 ` Manivannan Sadhasivam
2023-03-07 14:40 ` Devi Priya
2023-03-07 14:56 ` Dmitry Baryshkov [this message]
2023-03-08 8:49 ` Devi Priya
2023-02-14 16:41 ` [PATCH 2/7] PCI: qcom: Add IPQ9574 PCIe support Devi Priya
2023-02-16 11:38 ` Sricharan Ramabadhran
2023-02-20 13:41 ` Devi Priya
2023-02-20 14:51 ` Kathiravan T
2023-02-20 15:25 ` Devi Priya
2023-02-24 8:29 ` Manivannan Sadhasivam
2023-02-28 5:28 ` Devi Priya
2023-02-14 16:41 ` [PATCH 3/7] dt-bindings: phy: qcom,qmp-pcie: Add ipq9574 compatible Devi Priya
2023-02-16 10:30 ` Krzysztof Kozlowski
2023-02-14 16:41 ` [PATCH 4/7] phy: qcom-qmp-pcie: Add support for IPQ9574 platform Devi Priya
2023-02-14 16:41 ` [PATCH 5/7] dt-bindings: clock: Add PCIe pipe clock definitions Devi Priya
2023-02-15 2:30 ` Stephen Boyd
2023-02-15 3:18 ` Devi Priya
2023-02-14 16:41 ` [PATCH 6/7] clk: qcom: gcc-ipq9574: Add PCIe related clocks Devi Priya
2023-02-17 8:41 ` Sricharan Ramabadhran
2023-02-20 13:43 ` Devi Priya
2023-02-17 8:43 ` Sricharan Ramabadhran
2023-02-20 13:44 ` Devi Priya
2023-02-14 16:41 ` [PATCH 7/7] arm64: dts: qcom: ipq9574: Add PCIe PHYs and controller nodes Devi Priya
2023-02-17 8:35 ` Sricharan Ramabadhran
2023-02-20 13:47 ` Devi Priya
2023-02-24 6:57 ` Kathiravan T
2023-03-03 12:09 ` Devi Priya
2023-02-24 8:59 ` Manivannan Sadhasivam
2023-03-07 14:42 ` Devi Priya
2023-02-17 8:48 ` [PATCH 0/7] Add PCIe support for IPQ9574 Sricharan Ramabadhran
2023-02-20 13:48 ` Devi Priya
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=CAA8EJpo-_PXhBnKWD-TWEqY8+uAEjbRsrhJ7XO1PTcYV-MHV9Q@mail.gmail.com \
--to=dmitry.baryshkov@linaro.org \
--cc=agross@kernel.org \
--cc=andersson@kernel.org \
--cc=bhelgaas@google.com \
--cc=devicetree@vger.kernel.org \
--cc=kishon@kernel.org \
--cc=konrad.dybcio@linaro.org \
--cc=krzysztof.kozlowski+dt@linaro.org \
--cc=kw@linux.com \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-clk@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=linux-phy@lists.infradead.org \
--cc=lpieralisi@kernel.org \
--cc=mani@kernel.org \
--cc=mturquette@baylibre.com \
--cc=p.zabel@pengutronix.de \
--cc=quic_anusha@quicinc.com \
--cc=quic_arajkuma@quicinc.com \
--cc=quic_devipriy@quicinc.com \
--cc=quic_gokulsri@quicinc.com \
--cc=quic_kathirav@quicinc.com \
--cc=quic_sjaganat@quicinc.com \
--cc=quic_srichara@quicinc.com \
--cc=robh@kernel.org \
--cc=sboyd@kernel.org \
--cc=vkoul@kernel.org \
/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).