Re: [PATCH v2] PCI: v3: fix missing clk_disable_unprepare() on error in v3_pci_probe

[Qinglang Miao]

在 2020/11/3 22:16, Rob Herring 写道:
> On Tue, Nov 3, 2020 at 1:28 AM Qinglang Miao <miaoqinglang@xxxxxxxxxx> wrote:
> > Fix the missing clk_disable_unprepare() before return
> > from v3_pci_probe() in the error handling case.
> >
> > Moving the clock enable later to avoid some fixes.
> >
> > Fixes: 6e0832fa432e (" PCI: Collect all native drivers under drivers/pci/controller/")
>
> I don't think this commit caused the problem.
>
> > Suggested-by: Rob Herring <robh@xxxxxxxxxx>
> > Signed-off-by: Qinglang Miao <miaoqinglang@xxxxxxxxxx>
> > ---
> >   drivers/pci/controller/pci-v3-semi.c | 40 ++++++++++++++++------------
> >   1 file changed, 23 insertions(+), 17 deletions(-)
> >
> > diff --git a/drivers/pci/controller/pci-v3-semi.c b/drivers/pci/controller/pci-v3-semi.c
> > index 154a53986..90520555b 100644
> > --- a/drivers/pci/controller/pci-v3-semi.c
> > +++ b/drivers/pci/controller/pci-v3-semi.c
> > @@ -725,18 +725,6 @@ static int v3_pci_probe(struct platform_device *pdev)
> >          host->sysdata = v3;
> >          v3->dev = dev;
> >
> > -       /* Get and enable host clock */
> > -       clk = devm_clk_get(dev, NULL);
> > -       if (IS_ERR(clk)) {
> > -               dev_err(dev, "clock not found\n");
> > -               return PTR_ERR(clk);
> > -       }
> > -       ret = clk_prepare_enable(clk);
> > -       if (ret) {
> > -               dev_err(dev, "unable to enable clock\n");
> > -               return ret;
> > -       }
> > -
> >          regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >          v3->base = devm_ioremap_resource(dev, regs);
> >          if (IS_ERR(v3->base))
> > @@ -761,17 +749,31 @@ static int v3_pci_probe(struct platform_device *pdev)
> >          if (IS_ERR(v3->config_base))
> >                  return PTR_ERR(v3->config_base);
> >
> > +       /* Get and enable host clock */
> > +       clk = devm_clk_get(dev, NULL);
> > +       if (IS_ERR(clk)) {
> > +               dev_err(dev, "clock not found\n");
> > +               return PTR_ERR(clk);
> > +       }
> > +       ret = clk_prepare_enable(clk);
> > +       if (ret) {
> > +               dev_err(dev, "unable to enable clock\n");
> > +               return ret;
> > +       }
> > +
> >          /* 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);
> >          if (ret < 0) {
> >                  dev_err(dev,
> >                          "unable to request PCIv3 error IRQ %d (%d)\n",
> >                          irq, ret);
> > +               clk_disable_unprepare(clk);
> >                  return ret;
> >          }
> >
> > @@ -814,13 +816,15 @@ static int v3_pci_probe(struct platform_device *pdev)
> >                  ret = v3_pci_setup_resource(v3, host, win);
> >                  if (ret) {
> >                          dev_err(dev, "error setting up resources\n");
> > +                       clk_disable_unprepare(clk);
> >                          return ret;
> >                  }
> >          }
> >          ret = v3_pci_parse_map_dma_ranges(v3, np);
> > -       if (ret)
> > +       if (ret) {
> > +               clk_disable_unprepare(clk);
> >                  return ret;
> > -
> > +       }
> >          /*
> >           * Disable PCI to host IO cycles, enable I/O buffers @3.3V,
> >           * set AD_LOW0 to 1 if one of the LB_MAP registers choose
> > @@ -862,8 +866,10 @@ static int v3_pci_probe(struct platform_device *pdev)
> >          /* Special Integrator initialization */
> >          if (of_device_is_compatible(np, "arm,integrator-ap-pci")) {
> >                  ret = v3_integrator_init(v3);
> > -               if (ret)
> > +               if (ret) {
> > +                       clk_disable_unprepare(clk);
>
> You should make all these a goto and just have one clk_disable_unprepare() call.
>
> You are still missing error handling after pci_host_probe().
Hi Rob,

I've sent a v3 patch towards this bug.

Thanks a lot for your advice.
> >                          return ret;
> > +               }
> >          }
> >
> >          /* Post-init: enable PCI memory and invalidate (master already on) */
> > --
> > 2.23.0
> .