From: Bjorn Helgaas <helgaas@kernel.org>
To: Krishna Chaitanya Chundru <quic_krichai@quicinc.com>
Cc: linux-pci@vger.kernel.org, linux-arm-msm@vger.kernel.org,
linux-kernel@vger.kernel.org, mka@chromium.org,
quic_vbadigan@quicinc.com, quic_hemantk@quicinc.com,
quic_nitegupt@quicinc.com, quic_skananth@quicinc.com,
quic_ramkri@quicinc.com, manivannan.sadhasivam@linaro.org,
swboyd@chromium.org, dmitry.baryshkov@linaro.org,
svarbanov@mm-sol.com, agross@kernel.org, andersson@kernel.org,
konrad.dybcio@somainline.org, lpieralisi@kernel.org,
robh@kernel.org, kw@linux.com, bhelgaas@google.com,
linux-phy@lists.infradead.org, vkoul@kernel.org, kishon@ti.com,
mturquette@baylibre.com, linux-clk@vger.kernel.org,
Bjorn Andersson <bjorn.andersson@linaro.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
linux-pm@vger.kernel.org, Marc Zyngier <maz@kernel.org>,
Kevin Rowland <kevin.p.rowland@gmail.com>
Subject: Re: [PATCH v7 1/5] PCI: qcom: Add system suspend and resume support
Date: Wed, 12 Oct 2022 19:44:44 -0500 [thread overview]
Message-ID: <20221013004444.GA3135316@bhelgaas> (raw)
In-Reply-To: <04ace1ae-26d0-4157-b7eb-8dff29895180@quicinc.com>
[+cc Marc, Kevin]
On Wed, Oct 12, 2022 at 07:36:52PM +0530, Krishna Chaitanya Chundru wrote:
> On 10/6/2022 2:43 AM, Bjorn Helgaas wrote:
[I'm declaring quote text bankruptcy and dropping the huge wall of
text. The IRQ affinity change you mention seems to be the critical
issue :)]
> > The PCIe spec clearly envisions Refclk being turned off
> > (sec 5.5.3.3.1) and PHYs being powered off (sec 5.5.3.2) while in
> > L1.2.
> >
> > I've been assuming L1.2 exit (which includes Refclk being turned on
> > and PHYs being powered up) is completely handled by hardware, but it
> > sounds like the Qcom controller needs software assistance which fields
> > an interrupt when CLKREQ# is asserted and turns on Refclk and the
> > PHYs?
> >
> > 5.5.3 does say "All Link and PHY state must be maintained during L1.2,
> > or must be restored upon exit using implementation specific means",
> > and maybe Qcom counts as using implementation specific means.
> >
> > I *am* concerned about whether software can do the L1.2 exit fast
> > enough, but the biggest reason I'm struggling with this is because
> > using the syscore framework to work around IRQ affinity changes that
> > happen late in suspend just seems kind of kludgy and it doesn't seem
> > like it fits cleanly in the power management model.
>
> Can you please suggest any another way to work around IRQ affinity
> changes.
One of your earlier patches [1] made dw_msi_mask_irq() look like this:
static void dw_msi_mask_irq(struct irq_data *d)
{
struct pcie_port *pp = irq_data_get_irq_chip_data(d->parent_data);
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
if (dw_pcie_link_up(pci))
pci_msi_mask_irq(d);
irq_chip_mask_parent(d);
}
That was an awful lot like Marc's suggestion [2] that the
pci_msi_mask_irq() should be redundant.
If it's truly redundant, maybe pci_msi_mask_irq() can be removed
from dw_msi_mask_irq() (and other similar *_mask_irq()
implementations) completely?
Bjorn
[1] https://lore.kernel.org/r/1659526134-22978-3-git-send-email-quic_krichai@quicinc.com
[2] https://lore.kernel.org/linux-pci/86k05m7dkr.wl-maz@kernel.org/
next prev parent reply other threads:[~2022-10-13 1:14 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-20 10:22 [PATCH v7 0/5] PCI: qcom: Add system suspend & resume support Krishna chaitanya chundru
2022-09-20 10:22 ` [PATCH v7 1/5] PCI: qcom: Add system suspend and " Krishna chaitanya chundru
2022-09-20 18:16 ` Bjorn Helgaas
2022-09-21 9:53 ` Krishna Chaitanya Chundru
2022-09-21 16:56 ` Bjorn Helgaas
2022-09-22 15:39 ` Krishna Chaitanya Chundru
2022-09-22 18:42 ` Bjorn Helgaas
2022-09-23 1:59 ` Krishna Chaitanya Chundru
2022-09-23 14:26 ` Bjorn Helgaas
2022-09-25 1:53 ` Krishna Chaitanya Chundru
2022-09-28 14:32 ` Krishna Chaitanya Chundru
2022-09-26 15:30 ` Krishna Chaitanya Chundru
2022-09-29 18:53 ` Bjorn Helgaas
2022-10-03 12:10 ` Krishna Chaitanya Chundru
2022-10-05 21:13 ` Bjorn Helgaas
2022-10-12 14:06 ` Krishna Chaitanya Chundru
2022-10-13 0:44 ` Bjorn Helgaas [this message]
2022-09-20 21:58 ` Jeff Johnson
2022-09-20 10:22 ` [PATCH v7 2/5] PCI: qcom: Add retry logic for link to be stable in either L1.1 or L1.2 Krishna chaitanya chundru
2022-09-20 22:00 ` Jeff Johnson
2022-09-24 6:05 ` Vinod Koul
2022-09-25 1:51 ` Krishna Chaitanya Chundru
2022-09-20 10:22 ` [PATCH v7 3/5] phy: core: Add support for phy suspend & resume Krishna chaitanya chundru
2022-09-20 10:22 ` [PATCH v7 4/5] phy: qcom: Add power suspend & resume callbacks to PCIe phy Krishna chaitanya chundru
2022-09-20 10:22 ` [PATCH v7 5/5] clk: qcom: gcc-sc7280: Update the .pwrsts for PCIe GDSC Krishna chaitanya chundru
2022-09-27 3:23 ` (subset) [PATCH v7 0/5] PCI: qcom: Add system suspend & resume support Bjorn Andersson
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