linux-kernel - Re: [PATCH v2 2/6] PCI: brcmstb: Split brcm_pcie_setup() into two funcs

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Date:   Mon, 18 Jul 2022 20:01:59 +0200
From:   Pali Rohár <pali@...nel.org>
To:     Bjorn Helgaas <helgaas@...nel.org>
Cc:     Jim Quinlan <james.quinlan@...adcom.com>,
        Jim Quinlan <jim2101024@...il.com>,
        "open list:PCI NATIVE HOST BRIDGE AND ENDPOINT DRIVERS" 
        <linux-pci@...r.kernel.org>,
        Nicolas Saenz Julienne <nsaenz@...nel.org>,
        Bjorn Helgaas <bhelgaas@...gle.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
        Cyril Brulebois <kibi@...ian.org>,
        "maintainer:BROADCOM BCM7XXX ARM ARCHITECTURE" 
        <bcm-kernel-feedback-list@...adcom.com>,
        Florian Fainelli <f.fainelli@...il.com>,
        Lorenzo Pieralisi <lpieralisi@...nel.org>,
        Rob Herring <robh@...nel.org>,
        Krzysztof Wilczyński <kw@...ux.com>,
        "moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE" 
        <linux-rpi-kernel@...ts.infradead.org>,
        "moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE" 
        <linux-arm-kernel@...ts.infradead.org>,
        open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 2/6] PCI: brcmstb: Split brcm_pcie_setup() into two
 funcs

On Monday 18 July 2022 12:05:28 Bjorn Helgaas wrote:
> On Mon, Jul 18, 2022 at 09:37:08AM -0400, Jim Quinlan wrote:
> > On Mon, Jul 18, 2022 at 9:11 AM Pali Rohár <pali@...nel.org> wrote:
> > >
> > > Hello!
> > >
> > > On Saturday 16 July 2022 18:24:49 Jim Quinlan wrote:
> > > > @@ -948,6 +941,40 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
> > > >       if (pcie->gen)
> > > >               brcm_pcie_set_gen(pcie, pcie->gen);
> > > >
> > > > +     /* Don't advertise L0s capability if 'aspm-no-l0s' */
> > > > +     aspm_support = PCIE_LINK_STATE_L1;
> > > > +     if (!of_property_read_bool(pcie->np, "aspm-no-l0s"))
> > > > +             aspm_support |= PCIE_LINK_STATE_L0S;
> > > > +     tmp = readl(base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY);
> > > > +     u32p_replace_bits(&tmp, aspm_support,
> > > > +             PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK);
> > > > +     writel(tmp, base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY);
> > > > +
> > > > +     /*
> > > > +      * For config space accesses on the RC, show the right class for
> > > > +      * a PCIe-PCIe bridge (the default setting is to be EP mode).
> > > > +      */
> > > > +     tmp = readl(base + PCIE_RC_CFG_PRIV1_ID_VAL3);
> > > > +     u32p_replace_bits(&tmp, 0x060400,
> > >
> > > There is already macro PCI_CLASS_BRIDGE_PCI_NORMAL, so please use it
> > > instead of magic constant.
> > 
> > Will do, thanks.
> 
> I can fix that up locally.

Great!

I did git grep on recent master branch and found another candidates with
magic numbers which refers to PCI_CLASS_BRIDGE_PCI_NORMAL:

arch/mips/pci/pci-mt7620.c:     pcie_w32(0x06040001, RALINK_PCI0_CLASS);
arch/mips/pci/pci-rt3883.c:     rt3883_pci_w32(rpc, 0x06040001, RT3883_PCI_REG_CLASS(1));
arch/powerpc/platforms/4xx/pci.c:               out_le32(mbase + 0x208, 0x06040001);
drivers/pci/controller/pcie-brcmstb.c:  u32p_replace_bits(&tmp, 0x060400,

(class code is stored in upper 24 bits of 32-bit register, so it makes
sense that on lowest 8 bits is something more - 0x01)

What do you think? Does it make sense to send patch which replace above
hex numbers by macros?

> > > I introduced it recently in commit:
> > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=904b10fb189cc15376e9bfce1ef0282e68b0b004
> > >
> > > > +                       PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK);
> > > > +     writel(tmp, base + PCIE_RC_CFG_PRIV1_ID_VAL3);
> > > > +
> > > > +     return 0;
> > > > +}
> 
> 
> 
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel@...ts.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 

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