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 <miaoqingl...@huawei.com> wrote:

Fix the missing clk_disable_unprepare() before return
from v3_pci_probe() in the error handling case.

Signed-off-by: Qinglang Miao <miaoqingl...@huawei.com>
---
  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
.