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SubjectRe: [PATCH] PCI: tegra: Use PTR_ERR_OR_ZERO
On Wed, Aug 30, 2017 at 04:25:47PM +0200, Thierry Reding wrote:
> On Wed, Aug 30, 2017 at 08:59:31AM -0500, Bjorn Helgaas wrote:
> > On Tue, Aug 29, 2017 at 03:55:17PM +0200, Thierry Reding wrote:
> > > On Tue, Aug 29, 2017 at 07:09:00PM +0530, Himanshu Jha wrote:
> > > > Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR
> > > >
> > > > Signed-off-by: Himanshu Jha <himanshujha199640@gmail.com>
> > > > ---
> > > > drivers/pci/host/pci-tegra.c | 5 +----
> > > > 1 file changed, 1 insertion(+), 4 deletions(-)
> > > >
> > > > diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
> > > > index 9c40da5..90cda5b 100644
> > > > --- a/drivers/pci/host/pci-tegra.c
> > > > +++ b/drivers/pci/host/pci-tegra.c
> > > > @@ -1156,10 +1156,7 @@ static int tegra_pcie_resets_get(struct tegra_pcie *pcie)
> > > > return PTR_ERR(pcie->afi_rst);
> > > >
> > > > pcie->pcie_xrst = devm_reset_control_get_exclusive(dev, "pcie_x");
> > > > - if (IS_ERR(pcie->pcie_xrst))
> > > > - return PTR_ERR(pcie->pcie_xrst);
> > > > -
> > > > - return 0;
> > > > + return PTR_ERR_OR_ZERO(pcie->pcie_xrst);
> > > > }
> > >
> > > I'm not a big fan of this construct because it's a pain to undo this if
> > > ever we need to add code to this function. But since we do have scripts
> > > that will flag this, I guess this would pop up every now and again. The
> > > driver is unlikely to change in this part, too, so:
> >
> > Thanks for pointing this out. Do you know what the benefit of
> > PTR_ERR_OR_ZERO() is? To me, it makes the following code harder
> > to read because the error tests are no longer parallel:
> >
> > ...
> > res->ahb_reset = devm_reset_control_get(dev, "ahb");
> > if (IS_ERR(res->ahb_reset))
> > return PTR_ERR(res->ahb_reset);
> >
> > res->por_reset = devm_reset_control_get(dev, "por");
> > if (IS_ERR(res->por_reset))
> > return PTR_ERR(res->por_reset);
> >
> > res->phy_reset = devm_reset_control_get(dev, "phy");
> > return PTR_ERR_OR_ZERO(res->phy_reset);
> >
> > So I'd be inclined to avoid it unless there's some significant benefit.
>
> Yeah, I don't like the optics much either. Aside from the fact that it
> reduces the line count, I'm not aware of any benefits that this inline
> function has. It doesn't have any side-effects or anything, just wraps
> the common pattern into a single line.
>
> Looking at the history of the semantic patch that is the basis for the
> conversions (scripts/coccinelle/api/ptr_ret.cocci), or the static inline
> function itself, no rationale is given for why people prefer this. I've
> certainly seen such patches applied in some cases, but I've also seen
> other maintainers (including myself) reject them because of personal
> preference.

OK, I'm going to drop this then.

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