| Message ID | 20190705084850.30777-1-jonathanh@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | PCI: tegra: Fix support for GPIO based PERST# | expand |
On Fri, Jul 05, 2019 at 09:48:50AM +0100, Jon Hunter wrote: > Commit 5e5e9c23f82a ("PCI: tegra: Add support for GPIO based PERST#") > calls the function devm_gpiod_get_from_of_node() to request a GPIO. > Unfortunately, around the same time this was merged, commit 025bf37725f1 > ("gpio: Fix return value mismatch of function gpiod_get_from_of_node()") > was also merged to fix the return value of the function > devm_gpiod_get_from_of_node() that was incorrectly returning NULL > instead of an error pointer encoded with -ENOENT if no GPIO was found. > When this fix for the GPIO subsystem was merged, PCI support for Tegra > devices that did not provide a GPIO for the PERST# (which is optional) > broke because the Tegra PCI driver was expecting NULL to be returned if > no GPIO was present and not -ENOENT. > > Fix this by checking to see if -ENOENT is returned from the function > devm_gpiod_get_from_of_node(), to indicate there is no GPIO for PERST# > present, and if this is the case set the variable 'reset_gpio' to NULL. > If the variable 'reset_gpio' is NULL then the Tegra PCI driver will > fallback to using the AFI register to toggle the PERST#. Finally, > correct the comment now that NULL is no longer returned from > devm_gpiod_get_from_of_node(). > > Fixes: 5e5e9c23f82a ("PCI: tegra: Add support for GPIO based PERST#") > Signed-off-by: Jon Hunter <jonathanh@nvidia.com> > --- > drivers/pci/controller/pci-tegra.c | 16 ++++++++++------ > 1 file changed, 10 insertions(+), 6 deletions(-) Can I squash this in the original commit (ie Fixes: tag above) ? I do not think there is any issue with that, if there is please do let me know. Thanks, Lorenzo > diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c > index 9cc03a2549c0..ff8a346f3e04 100644 > --- a/drivers/pci/controller/pci-tegra.c > +++ b/drivers/pci/controller/pci-tegra.c > @@ -2295,18 +2295,22 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie) > } > > /* > - * Returns null if reset-gpios property is not populated and > - * fall back to using AFI per port register to toggle PERST# > - * SFIO line. > + * Returns -ENOENT if reset-gpios property is not populated > + * and in this case fall back to using AFI per port register > + * to toggle PERST# SFIO line. > */ > rp->reset_gpio = devm_gpiod_get_from_of_node(dev, port, > "reset-gpios", 0, > GPIOD_OUT_LOW, > label); > if (IS_ERR(rp->reset_gpio)) { > - err = PTR_ERR(rp->reset_gpio); > - dev_err(dev, "failed to get reset GPIO: %d\n", err); > - return err; > + if (PTR_ERR(rp->reset_gpio) == -ENOENT) { > + rp->reset_gpio = NULL; > + } else { > + dev_err(dev, "failed to get reset GPIO: %d\n", > + err); > + return PTR_ERR(rp->reset_gpio); > + } > } > > list_add_tail(&rp->list, &pcie->ports); > -- > 2.17.1 >
On 05-Jul-19 3:20 PM, Lorenzo Pieralisi wrote: > On Fri, Jul 05, 2019 at 09:48:50AM +0100, Jon Hunter wrote: >> Commit 5e5e9c23f82a ("PCI: tegra: Add support for GPIO based PERST#") >> calls the function devm_gpiod_get_from_of_node() to request a GPIO. >> Unfortunately, around the same time this was merged, commit 025bf37725f1 >> ("gpio: Fix return value mismatch of function gpiod_get_from_of_node()") >> was also merged to fix the return value of the function >> devm_gpiod_get_from_of_node() that was incorrectly returning NULL >> instead of an error pointer encoded with -ENOENT if no GPIO was found. >> When this fix for the GPIO subsystem was merged, PCI support for Tegra >> devices that did not provide a GPIO for the PERST# (which is optional) >> broke because the Tegra PCI driver was expecting NULL to be returned if >> no GPIO was present and not -ENOENT. >> >> Fix this by checking to see if -ENOENT is returned from the function >> devm_gpiod_get_from_of_node(), to indicate there is no GPIO for PERST# >> present, and if this is the case set the variable 'reset_gpio' to NULL. >> If the variable 'reset_gpio' is NULL then the Tegra PCI driver will >> fallback to using the AFI register to toggle the PERST#. Finally, >> correct the comment now that NULL is no longer returned from >> devm_gpiod_get_from_of_node(). >> >> Fixes: 5e5e9c23f82a ("PCI: tegra: Add support for GPIO based PERST#") >> Signed-off-by: Jon Hunter <jonathanh@nvidia.com> >> --- >> drivers/pci/controller/pci-tegra.c | 16 ++++++++++------ >> 1 file changed, 10 insertions(+), 6 deletions(-) > Can I squash this in the original commit (ie Fixes: tag above) ? I do > not think there is any issue with that, if there is please do let me > know. > > Thanks, > Lorenzo Reviewed-by: Manikanta Maddireddy Thank you Jon for publishing the fix. Hi Lorenzo, Yes, this patch can be squashed in the original commit. Apologies for the inconvenience. Manikanta >> diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c >> index 9cc03a2549c0..ff8a346f3e04 100644 >> --- a/drivers/pci/controller/pci-tegra.c >> +++ b/drivers/pci/controller/pci-tegra.c >> @@ -2295,18 +2295,22 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie) >> } >> >> /* >> - * Returns null if reset-gpios property is not populated and >> - * fall back to using AFI per port register to toggle PERST# >> - * SFIO line. >> + * Returns -ENOENT if reset-gpios property is not populated >> + * and in this case fall back to using AFI per port register >> + * to toggle PERST# SFIO line. >> */ >> rp->reset_gpio = devm_gpiod_get_from_of_node(dev, port, >> "reset-gpios", 0, >> GPIOD_OUT_LOW, >> label); >> if (IS_ERR(rp->reset_gpio)) { >> - err = PTR_ERR(rp->reset_gpio); >> - dev_err(dev, "failed to get reset GPIO: %d\n", err); >> - return err; >> + if (PTR_ERR(rp->reset_gpio) == -ENOENT) { >> + rp->reset_gpio = NULL; >> + } else { >> + dev_err(dev, "failed to get reset GPIO: %d\n", >> + err); >> + return PTR_ERR(rp->reset_gpio); >> + } >> } >> >> list_add_tail(&rp->list, &pcie->ports); >> -- >> 2.17.1 >>
diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c index 9cc03a2549c0..ff8a346f3e04 100644 --- a/drivers/pci/controller/pci-tegra.c +++ b/drivers/pci/controller/pci-tegra.c @@ -2295,18 +2295,22 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie) } /* - * Returns null if reset-gpios property is not populated and - * fall back to using AFI per port register to toggle PERST# - * SFIO line. + * Returns -ENOENT if reset-gpios property is not populated + * and in this case fall back to using AFI per port register + * to toggle PERST# SFIO line. */ rp->reset_gpio = devm_gpiod_get_from_of_node(dev, port, "reset-gpios", 0, GPIOD_OUT_LOW, label); if (IS_ERR(rp->reset_gpio)) { - err = PTR_ERR(rp->reset_gpio); - dev_err(dev, "failed to get reset GPIO: %d\n", err); - return err; + if (PTR_ERR(rp->reset_gpio) == -ENOENT) { + rp->reset_gpio = NULL; + } else { + dev_err(dev, "failed to get reset GPIO: %d\n", + err); + return PTR_ERR(rp->reset_gpio); + } } list_add_tail(&rp->list, &pcie->ports);
Commit 5e5e9c23f82a ("PCI: tegra: Add support for GPIO based PERST#") calls the function devm_gpiod_get_from_of_node() to request a GPIO. Unfortunately, around the same time this was merged, commit 025bf37725f1 ("gpio: Fix return value mismatch of function gpiod_get_from_of_node()") was also merged to fix the return value of the function devm_gpiod_get_from_of_node() that was incorrectly returning NULL instead of an error pointer encoded with -ENOENT if no GPIO was found. When this fix for the GPIO subsystem was merged, PCI support for Tegra devices that did not provide a GPIO for the PERST# (which is optional) broke because the Tegra PCI driver was expecting NULL to be returned if no GPIO was present and not -ENOENT. Fix this by checking to see if -ENOENT is returned from the function devm_gpiod_get_from_of_node(), to indicate there is no GPIO for PERST# present, and if this is the case set the variable 'reset_gpio' to NULL. If the variable 'reset_gpio' is NULL then the Tegra PCI driver will fallback to using the AFI register to toggle the PERST#. Finally, correct the comment now that NULL is no longer returned from devm_gpiod_get_from_of_node(). Fixes: 5e5e9c23f82a ("PCI: tegra: Add support for GPIO based PERST#") Signed-off-by: Jon Hunter <jonathanh@nvidia.com> --- drivers/pci/controller/pci-tegra.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)