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

From: Rob Herring
Date: Mon Nov 02 2020 - 08:48:23 EST


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))


> 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