Re: [PATCH] PCI: v3: fix missing clk_disable_unprepare() on error in v3_pci_probe

[miaoqinglang]

在 2020/11/2 21:48, Rob Herring 写道:
> On Thu, Oct 29, 2020 at 8:28 PM Qinglang Miao <miaoqinglang@xxxxxxxxxx> wrote:
> > Fix the missing clk_disable_unprepare() before return
> > from v3_pci_probe() in the error handling case.
> >
> > Signed-off-by: Qinglang Miao <miaoqinglang@xxxxxxxxxx>
> > ---
> >   drivers/pci/controller/pci-v3-semi.c | 14 +++++++++++---
> >   1 file changed, 11 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/pci/controller/pci-v3-semi.c b/drivers/pci/controller/pci-v3-semi.c
> > index 154a53986..e24abc5b4 100644
> > --- a/drivers/pci/controller/pci-v3-semi.c
> > +++ b/drivers/pci/controller/pci-v3-semi.c
> > @@ -739,8 +739,10 @@ static int v3_pci_probe(struct platform_device *pdev)
> >
> >          regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >          v3->base = devm_ioremap_resource(dev, regs);
> > -       if (IS_ERR(v3->base))
> > +       if (IS_ERR(v3->base)) {
> > +               clk_disable_unprepare(clk);
>
> You can reorder things moving the clock enable later (after mapping
> resources, but before devm_request_irq) and avoid some of these. Also
> move this check down:
>
> if (readl(v3->base + V3_LB_IO_BASE) != (regs->start >> 16))
Hi Rob,

I've sent a new patch which reorder things and cover all error branches.

But I'm not sure why and where should I move this check down:
if (readl(v3->base + V3_LB_IO_BASE) != (regs->start >> 16)).  So I 
didn't move it in current version.

If you think it's still necessary, please let me know.

Thanks.
> >                  return PTR_ERR(v3->base);
> > +       }
> >          /*
> >           * The hardware has a register with the physical base address
> >           * of the V3 controller itself, verify that this is the same
> > @@ -754,17 +756,22 @@ static int v3_pci_probe(struct platform_device *pdev)
> >          regs = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> >          if (resource_size(regs) != SZ_16M) {
> >                  dev_err(dev, "config mem is not 16MB!\n");
> > +               clk_disable_unprepare(clk);
> >                  return -EINVAL;
> >          }
> >          v3->config_mem = regs->start;
> >          v3->config_base = devm_ioremap_resource(dev, regs);
> > -       if (IS_ERR(v3->config_base))
> > +       if (IS_ERR(v3->config_base)) {
> > +               clk_disable_unprepare(clk);
> >                  return PTR_ERR(v3->config_base);
> > +       }
> >
> >          /* Get and request error IRQ resource */
> >          irq = platform_get_irq(pdev, 0);
> > -       if (irq < 0)
> > +       if (irq < 0) {
> > +               clk_disable_unprepare(clk);
> >                  return irq;
> > +       }
> >
> >          ret = devm_request_irq(dev, irq, v3_irq, 0,
> >                          "PCIv3 error", v3);
> > @@ -772,6 +779,7 @@ static int v3_pci_probe(struct platform_device *pdev)
> >                  dev_err(dev,
> >                          "unable to request PCIv3 error IRQ %d (%d)\n",
> >                          irq, ret);
> > +               clk_disable_unprepare(clk);
> >                  return ret;
>
> You still leave the clock enabled if pci_host_probe() fails.
>
> Rob
> .