| Message ID | 20181226022236.71682-1-kjlu@umn.edu (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | pci: dwc: add a check for resetting gpio | expand |
Hi Kangjie, Thanks for the patch. On Tue, Dec 25, 2018 at 08:22:36PM -0600, Kangjie Lu wrote: > devm_gpio_request_one() could fail. The fix checks its status and issues > an error if it fails. > > Signed-off-by: Kangjie Lu <kjlu@umn.edu> > --- > drivers/pci/controller/dwc/pci-exynos.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pci-exynos.c b/drivers/pci/controller/dwc/pci-exynos.c > index cee5f2f590e2..e3a045e215d2 100644 > --- a/drivers/pci/controller/dwc/pci-exynos.c > +++ b/drivers/pci/controller/dwc/pci-exynos.c > @@ -226,9 +226,12 @@ static void exynos_pcie_assert_reset(struct exynos_pcie *ep) > struct dw_pcie *pci = ep->pci; > struct device *dev = pci->dev; > > - if (ep->reset_gpio >= 0) > - devm_gpio_request_one(dev, ep->reset_gpio, > - GPIOF_OUT_INIT_HIGH, "RESET"); > + if (ep->reset_gpio >= 0) { > + if (devm_gpio_request_one(dev, ep->reset_gpio, > + GPIOF_OUT_INIT_HIGH, "RESET")) > + dev_err(dev, "Failed requesting reset gpio %d\n", > + ep->reset_gpio); > + } Even before your patch, this code doesn't make sense to me. devm_gpio_request_one() is a setup function and should be called in the probe path. The "assert_reset" path should do something like gpio_set_value(). See other callers, e.g., imx6_pcie_probe() histb_pcie_probe() mvebu_pcie_parse_port() I'm skeptical that exynos_pcie_assert_reset() ever worked as intended, so let's straighten that out before worrying about checking the return code from devm_gpio_request_one(). The result should be two patches: (1) fix the devm_gpio_request_one() usage, and (2) check the devm_gpio_request_one() return value. > }
diff --git a/drivers/pci/controller/dwc/pci-exynos.c b/drivers/pci/controller/dwc/pci-exynos.c index cee5f2f590e2..e3a045e215d2 100644 --- a/drivers/pci/controller/dwc/pci-exynos.c +++ b/drivers/pci/controller/dwc/pci-exynos.c @@ -226,9 +226,12 @@ static void exynos_pcie_assert_reset(struct exynos_pcie *ep) struct dw_pcie *pci = ep->pci; struct device *dev = pci->dev; - if (ep->reset_gpio >= 0) - devm_gpio_request_one(dev, ep->reset_gpio, - GPIOF_OUT_INIT_HIGH, "RESET"); + if (ep->reset_gpio >= 0) { + if (devm_gpio_request_one(dev, ep->reset_gpio, + GPIOF_OUT_INIT_HIGH, "RESET")) + dev_err(dev, "Failed requesting reset gpio %d\n", + ep->reset_gpio); + } } static int exynos_pcie_establish_link(struct exynos_pcie *ep)
devm_gpio_request_one() could fail. The fix checks its status and issues an error if it fails. Signed-off-by: Kangjie Lu <kjlu@umn.edu> --- drivers/pci/controller/dwc/pci-exynos.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)