From: Remi Pommarel <repk@triplefau.lt>
To: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
Bjorn Helgaas <helgaas@kernel.org>,
Ellie Reeves <ellierevves@gmail.com>,
linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] PCI: aardvark: Fix PCI_EXP_RTCTL conf register writing
Date: Fri, 14 Jun 2019 00:06:54 +0200 [thread overview]
Message-ID: <20190613220653.GB12859@voidbox.localdomain> (raw)
In-Reply-To: <20190613161441.GA2247@e121166-lin.cambridge.arm.com>
On Thu, Jun 13, 2019 at 05:14:41PM +0100, Lorenzo Pieralisi wrote:
> On Wed, May 22, 2019 at 11:33:49PM +0200, Remi Pommarel wrote:
> > PCI_EXP_RTCTL is used to activate PME interrupt only, so writing into it
> > should not modify other interrupts' mask (such as ISR0).
> >
> > Fixes: 6302bf3ef78d ("PCI: Init PCIe feature bits for managed host bridge alloc")
> > Signed-off-by: Remi Pommarel <repk@triplefau.lt>
> > ---
> > Please note that I will unlikely be able to answer any comments from May
> > 24th to June 10th.
> > ---
> > drivers/pci/controller/pci-aardvark.c | 10 +++++++---
> > 1 file changed, 7 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
> > index 134e0306ff00..27102d3b4f9c 100644
> > --- a/drivers/pci/controller/pci-aardvark.c
> > +++ b/drivers/pci/controller/pci-aardvark.c
> > @@ -451,10 +451,14 @@ advk_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge,
> > advk_writel(pcie, new, PCIE_CORE_PCIEXP_CAP + reg);
> > break;
> >
> > - case PCI_EXP_RTCTL:
> > - new = (new & PCI_EXP_RTCTL_PMEIE) << 3;
> > - advk_writel(pcie, new, PCIE_ISR0_MASK_REG);
> > + case PCI_EXP_RTCTL: {
> > + /* Only mask/unmask PME interrupt */
> > + u32 val = advk_readl(pcie, PCIE_ISR0_MASK_REG) &
> > + ~PCIE_MSG_PM_PME_MASK;
> > + val |= (new & PCI_EXP_RTCTL_PMEIE) << 3;
>
> I know you have not introduced this code but maybe we can
> take an opportunity to clarify it (that << 3 shift obfuscates
> a bit):
>
> u32 val = advk_readl(pcie, PCIE_ISR0_MASK_REG) &
> ~PCIE_MSG_PM_PME_MASK;
>
> if (new & PCI_EXP_RTCTL_PMEIE)
> val |= PCIE_MSG_PM_PME_MASK;
>
> advk_writel(pcie, val, PCIE_ISR0_MASK_REG);
> break;
>
> Or I am not reading the code correctly ?
Sure, that clarifies the code at the point where I realize that the
"<< 3" from the original code was off by one and the mask polarity was
inverted. So I'll fix all that in the v2.
Thanks.
--
Remi
prev parent reply other threads:[~2019-06-13 21:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-22 21:33 [PATCH] PCI: aardvark: Fix PCI_EXP_RTCTL conf register writing Remi Pommarel
2019-06-13 16:14 ` Lorenzo Pieralisi
2019-06-13 22:06 ` Remi Pommarel [this message]
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