[PATCH 1/2] Revert "usb: xhci: tegra: Fix error check"

[PATCH 1/2] Revert "usb: xhci: tegra: Fix error check"

[Dan Carpenter]

This reverts commit 18fc7c435be3f17ea26a21b2e2312fcb9088e01f.

The reverted commit was based on static analysis and a misunderstanding
of how PTR_ERR() and NULLs are supposed to work.  When a function
returns both pointer errors and NULL then normally the NULL means
"continue operating without a feature because it was deliberately
turned off".  The NULL should not be treated as a failure.  If a driver
cannot work when that feature is disabled then the KConfig should
enforce that the function cannot return NULL.  We should not need to
test for it.

In this code, the patch means that certain tegra_xusb_probe() will
fail if the firmware supports power-domains but CONFIG_PM is disabled.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
My patch also is based on static analysis and reviewing the code so,
you know, probably best to be careful all round.

 drivers/usb/host/xhci-tegra.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/host/xhci-tegra.c b/drivers/usb/host/xhci-tegra.c
index 6ca8a37e53e1..4693d83351c6 100644
--- a/drivers/usb/host/xhci-tegra.c
+++ b/drivers/usb/host/xhci-tegra.c
@@ -1145,15 +1145,15 @@ static int tegra_xusb_powerdomain_init(struct device *dev,
 	int err;
 
 	tegra->genpd_dev_host = dev_pm_domain_attach_by_name(dev, "xusb_host");
-	if (IS_ERR_OR_NULL(tegra->genpd_dev_host)) {
-		err = PTR_ERR(tegra->genpd_dev_host) ? : -ENODATA;
+	if (IS_ERR(tegra->genpd_dev_host)) {
+		err = PTR_ERR(tegra->genpd_dev_host);
 		dev_err(dev, "failed to get host pm-domain: %d\n", err);
 		return err;
 	}
 
 	tegra->genpd_dev_ss = dev_pm_domain_attach_by_name(dev, "xusb_ss");
-	if (IS_ERR_OR_NULL(tegra->genpd_dev_ss)) {
-		err = PTR_ERR(tegra->genpd_dev_ss) ? : -ENODATA;
+	if (IS_ERR(tegra->genpd_dev_ss)) {
+		err = PTR_ERR(tegra->genpd_dev_ss);
 		dev_err(dev, "failed to get superspeed pm-domain: %d\n", err);
 		return err;
 	}
-- 
2.39.2

[PATCH 2/2] Revert "usb: gadget: tegra-xudc: Fix error check in tegra_xudc_powerdomain_init()"

[Dan Carpenter]

This reverts commit f08aa7c80dac27ee00fa6827f447597d2fba5465.

The reverted commit was based on static analysis and a misunderstanding
of how PTR_ERR() and NULLs are supposed to work.  When a function
returns both pointer errors and NULL then normally the NULL means
"continue operating without a feature because it was deliberately
turned off".  The NULL should not be treated as a failure.  If a driver
cannot work when that feature is disabled then the KConfig should
enforce that the function cannot return NULL.  We should not need to
test for it.

In this driver, the bug means that probe cannot succeed when CONFIG_PM
is disabled.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
My patch also is based on static analysis and reviewing the code so,
you know, probably best to be careful all round.

 drivers/usb/gadget/udc/tegra-xudc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/gadget/udc/tegra-xudc.c b/drivers/usb/gadget/udc/tegra-xudc.c
index 83eaa65ddde3..df6028f7b273 100644
--- a/drivers/usb/gadget/udc/tegra-xudc.c
+++ b/drivers/usb/gadget/udc/tegra-xudc.c
@@ -3718,15 +3718,15 @@ static int tegra_xudc_powerdomain_init(struct tegra_xudc *xudc)
 	int err;
 
 	xudc->genpd_dev_device = dev_pm_domain_attach_by_name(dev, "dev");
-	if (IS_ERR_OR_NULL(xudc->genpd_dev_device)) {
-		err = PTR_ERR(xudc->genpd_dev_device) ? : -ENODATA;
+	if (IS_ERR(xudc->genpd_dev_device)) {
+		err = PTR_ERR(xudc->genpd_dev_device);
 		dev_err(dev, "failed to get device power domain: %d\n", err);
 		return err;
 	}
 
 	xudc->genpd_dev_ss = dev_pm_domain_attach_by_name(dev, "ss");
-	if (IS_ERR_OR_NULL(xudc->genpd_dev_ss)) {
-		err = PTR_ERR(xudc->genpd_dev_ss) ? : -ENODATA;
+	if (IS_ERR(xudc->genpd_dev_ss)) {
+		err = PTR_ERR(xudc->genpd_dev_ss);
 		dev_err(dev, "failed to get SuperSpeed power domain: %d\n", err);
 		return err;
 	}
-- 
2.39.2