* [PATCH] pci: dwc: add a check for resetting gpio
@ 2018-12-26 2:22 ` Kangjie Lu
0 siblings, 0 replies; 4+ messages in thread
From: Kangjie Lu @ 2018-12-26 2:22 UTC (permalink / raw)
To: kjlu
Cc: pakki001, Jingoo Han, Lorenzo Pieralisi, Bjorn Helgaas,
Kukjin Kim, Krzysztof Kozlowski, linux-pci, linux-arm-kernel,
linux-samsung-soc, linux-kernel
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);
+ }
}
static int exynos_pcie_establish_link(struct exynos_pcie *ep)
--
2.17.2 (Apple Git-113)
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH] pci: dwc: add a check for resetting gpio
@ 2018-12-26 2:22 ` Kangjie Lu
0 siblings, 0 replies; 4+ messages in thread
From: Kangjie Lu @ 2018-12-26 2:22 UTC (permalink / raw)
To: kjlu
Cc: Lorenzo Pieralisi, Jingoo Han, linux-pci, linux-kernel,
Krzysztof Kozlowski, linux-samsung-soc, Kukjin Kim, pakki001,
Bjorn Helgaas, linux-arm-kernel
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);
+ }
}
static int exynos_pcie_establish_link(struct exynos_pcie *ep)
--
2.17.2 (Apple Git-113)
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] pci: dwc: add a check for resetting gpio
2018-12-26 2:22 ` Kangjie Lu
@ 2018-12-31 20:40 ` Bjorn Helgaas
-1 siblings, 0 replies; 4+ messages in thread
From: Bjorn Helgaas @ 2018-12-31 20:40 UTC (permalink / raw)
To: Kangjie Lu
Cc: Lorenzo Pieralisi, Jingoo Han, linux-pci, linux-kernel,
Krzysztof Kozlowski, linux-samsung-soc, Kukjin Kim, pakki001,
linux-arm-kernel
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.
> }
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] pci: dwc: add a check for resetting gpio
@ 2018-12-31 20:40 ` Bjorn Helgaas
0 siblings, 0 replies; 4+ messages in thread
From: Bjorn Helgaas @ 2018-12-31 20:40 UTC (permalink / raw)
To: Kangjie Lu
Cc: linux-samsung-soc, Jingoo Han, pakki001, linux-kernel,
Krzysztof Kozlowski, Lorenzo Pieralisi, Kukjin Kim, linux-pci,
linux-arm-kernel
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.
> }
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2018-12-31 20:40 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-12-26 2:22 [PATCH] pci: dwc: add a check for resetting gpio Kangjie Lu
2018-12-26 2:22 ` Kangjie Lu
2018-12-31 20:40 ` Bjorn Helgaas
2018-12-31 20:40 ` Bjorn Helgaas
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.