Re: [PATCH v1] PCI: brcmstb: variable is missing proper initialization

From: Jim Quinlan
Date: Wed Nov 04 2020 - 09:48:21 EST


On Tue, Nov 3, 2020 at 2:38 PM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
>
> On Mon, Nov 02, 2020 at 03:57:12PM -0500, Jim Quinlan wrote:
> > The variable 'tmp' is used multiple times in the brcm_pcie_setup()
> > function. One such usage did not initialize 'tmp' to the current value of
> > the target register. By luck the mistake does not currently affect
> > behavior; regardless 'tmp' is now initialized properly.
>
> This is so trivial that there's probably no reason to post this again,
> but if you post a v2 for some reason, please update the subject to
> match the convention ("PCI: brcmstb: Verb ..."), e.g.,
>
> PCI: brcmstb: Initialize "tmp" before use
>
> The commit log does not say what the patch does, leaving it to the
> reader to infer it.

Got it.
Thanks,
Jim Quinlan
Broadcom STB
>
>
>
>
> Lorenzo will likely fix this up when he applies it.
>
> Incidental curiosity: where should I look to see what
> u32p_replace_bits() does? "git grep u32p_replace_bits" shows several
> calls, but no definitions.
>
> > Fixes: c0452137034b ("PCI: brcmstb: Add Broadcom STB PCIe host controller driver")
> > Suggested-by: Rafał Miłecki <zajec5@xxxxxxxxx>
> > Signed-off-by: Jim Quinlan <james.quinlan@xxxxxxxxxxxx>
> > ---
> > drivers/pci/controller/pcie-brcmstb.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
> > index bea86899bd5d..9c3d2982248d 100644
> > --- a/drivers/pci/controller/pcie-brcmstb.c
> > +++ b/drivers/pci/controller/pcie-brcmstb.c
> > @@ -893,6 +893,7 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
> > burst = 0x2; /* 512 bytes */
> >
> > /* Set SCB_MAX_BURST_SIZE, CFG_READ_UR_MODE, SCB_ACCESS_EN */
> > + tmp = readl(base + PCIE_MISC_MISC_CTRL);
> > u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_SCB_ACCESS_EN_MASK);
> > u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_CFG_READ_UR_MODE_MASK);
> > u32p_replace_bits(&tmp, burst, PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_MASK);
> > --
> > 2.17.1
> >
>
>

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