From: Bjorn Helgaas <helgaas@kernel.org>
To: Jim Quinlan <james.quinlan@broadcom.com>
Cc: "Jim Quinlan" <jim2101024@gmail.com>,
"open list:PCI NATIVE HOST BRIDGE AND ENDPOINT DRIVERS"
<linux-pci@vger.kernel.org>,
"Bjorn Helgaas" <bhelgaas@google.com>,
"Nicolas Saenz Julienne" <nsaenz@kernel.org>,
"Rob Herring" <robh@kernel.org>,
"Mark Brown" <broonie@kernel.org>,
"maintainer:BROADCOM BCM7XXX ARM ARCHITECTURE"
<bcm-kernel-feedback-list@broadcom.com>,
"Florian Fainelli" <f.fainelli@gmail.com>,
"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
"Krzysztof Wilczyński" <kw@linux.com>,
"moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE"
<linux-rpi-kernel@lists.infradead.org>,
"moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE"
<linux-arm-kernel@lists.infradead.org>,
"open list" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v8 1/8] PCI: brcmstb: Change brcm_phy_stop() to return void
Date: Tue, 16 Nov 2021 14:40:03 -0600 [thread overview]
Message-ID: <20211116204003.GA1678373@bhelgaas> (raw)
In-Reply-To: <CA+-6iNy86LG761MYvr-mB0de1TZ_EbJxzw0vFYfgXaa+96k=GA@mail.gmail.com>
On Mon, Nov 15, 2021 at 03:56:14PM -0500, Jim Quinlan wrote:
> On Thu, Nov 11, 2021 at 4:57 PM Bjorn Helgaas <helgaas@kernel.org> wrote:
> > On Wed, Nov 10, 2021 at 05:14:41PM -0500, Jim Quinlan wrote:
> > > We do not use the result of this function so make it void.
> >
> > I don't get it. Can you expand on this?
> >
> > brcm_phy_cntl() can return -EIO, which means brcm_phy_stop() can
> > return -EIO, which means brcm_pcie_suspend can return -EIO.
> > brcm_pcie_suspend() is the dev_pm_ops.suspend() method.
> >
> > So are you saying we never use the result of dev_pm_ops.suspend()?
>
> In this situation we are going into suspend. In doing so, any
> problems with the brcm phy may be erased/forgiven upon resume, since
> clocks are turned off and most power removed/reduced. An error from
> brcm_phy_stop() that becomes the return value of brcm_pcie_suspend()
> will bring a halt to the entire suspend IIRC. In fact, I forced a
> -EIO in this code and it panic'd on suspend. This is not really the
> behavior I want for what is most likely a recoverable error.
>
> Perhaps a dev_err(...) will suffice while still returning 0?
Maybe we just need a note about why we want to intentionally ignore
any errors here.
> I noticed that reset_control_rearm() also returns a value, and if that
> is in error it will not be erease/forgiven by suspend sleep. I will
> fix this.
>
> Regards,
> Jim Quinlan
> Broadcom STB
>
>
> >
> > > Signed-off-by: Jim Quinlan <jim2101024@gmail.com>
> > > ---
> > > drivers/pci/controller/pcie-brcmstb.c | 10 +++++-----
> > > 1 file changed, 5 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
> > > index cc30215f5a43..ff7d0d291531 100644
> > > --- a/drivers/pci/controller/pcie-brcmstb.c
> > > +++ b/drivers/pci/controller/pcie-brcmstb.c
> > > @@ -1111,9 +1111,10 @@ static inline int brcm_phy_start(struct brcm_pcie *pcie)
> > > return pcie->rescal ? brcm_phy_cntl(pcie, 1) : 0;
> > > }
> > >
> > > -static inline int brcm_phy_stop(struct brcm_pcie *pcie)
> > > +static inline void brcm_phy_stop(struct brcm_pcie *pcie)
> > > {
> > > - return pcie->rescal ? brcm_phy_cntl(pcie, 0) : 0;
> > > + if (pcie->rescal)
> > > + brcm_phy_cntl(pcie, 0);
> > > }
> > >
> > > static void brcm_pcie_turn_off(struct brcm_pcie *pcie)
> > > @@ -1143,14 +1144,13 @@ static void brcm_pcie_turn_off(struct brcm_pcie *pcie)
> > > static int brcm_pcie_suspend(struct device *dev)
> > > {
> > > struct brcm_pcie *pcie = dev_get_drvdata(dev);
> > > - int ret;
> > >
> > > brcm_pcie_turn_off(pcie);
> > > - ret = brcm_phy_stop(pcie);
> > > + brcm_phy_stop(pcie);
> > > reset_control_rearm(pcie->rescal);
> > > clk_disable_unprepare(pcie->clk);
> > >
> > > - return ret;
> > > + return 0;
> > > }
> > >
> > > static int brcm_pcie_resume(struct device *dev)
> > > --
> > > 2.17.1
> > >
next prev parent reply other threads:[~2021-11-16 20:40 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-10 22:14 [PATCH v8 0/8] PCI: brcmstb: have portdrv turn on sub-device power Jim Quinlan
2021-11-10 22:14 ` [PATCH v8 1/8] PCI: brcmstb: Change brcm_phy_stop() to return void Jim Quinlan
2021-11-11 21:57 ` Bjorn Helgaas
2021-11-15 20:56 ` Jim Quinlan
2021-11-16 20:40 ` Bjorn Helgaas [this message]
2021-11-10 22:14 ` [PATCH v8 2/8] dt-bindings: PCI: Correct brcmstb interrupts, interrupt-map Jim Quinlan
2021-11-10 22:14 ` [PATCH v8 3/8] dt-bindings: PCI: Add bindings for Brcmstb EP voltage regulators Jim Quinlan
2021-11-11 22:17 ` Bjorn Helgaas
2021-11-12 18:25 ` Jim Quinlan
2021-11-12 20:20 ` Bjorn Helgaas
2021-11-12 21:46 ` Rob Herring
2021-11-13 11:38 ` Pali Rohár
2021-11-10 22:14 ` [PATCH v8 4/8] PCI/portdrv: Create pcie_is_port_dev() func from existing code Jim Quinlan
2021-11-11 21:51 ` Florian Fainelli
2021-11-11 22:53 ` Rob Herring
2021-11-11 23:50 ` Krzysztof Wilczyński
2021-11-12 18:14 ` Jim Quinlan
2021-11-10 22:14 ` [PATCH v8 5/8] PCI/portdrv: add mechanism to turn on subdev regulators Jim Quinlan
2021-11-11 9:44 ` kernel test robot
2021-11-11 22:12 ` Bjorn Helgaas
2021-11-11 22:50 ` Rob Herring
2021-11-11 22:56 ` Rob Herring
2021-11-15 20:44 ` Jim Quinlan
2021-11-16 17:41 ` Rob Herring
2021-11-16 20:53 ` Pali Rohár
2021-11-17 15:14 ` Jim Quinlan
2021-11-17 15:45 ` Pali Rohár
2021-11-18 15:36 ` Jim Quinlan
2021-11-18 15:50 ` Pali Rohár
2021-11-17 14:46 ` Jim Quinlan
2021-11-11 23:38 ` Krzysztof Wilczyński
2021-11-15 20:26 ` Jim Quinlan
2021-11-10 22:14 ` [PATCH v8 6/8] PCI/portdrv: Do not turn off subdev regulators if EP can wake up Jim Quinlan
2021-11-10 22:14 ` [PATCH v8 7/8] PCI: brcmstb: Split brcm_pcie_setup() into two funcs Jim Quinlan
2021-11-10 22:14 ` [PATCH v8 8/8] PCI: brcmstb: Add control of subdevice voltage regulators Jim Quinlan
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