Re: [PATCH v4] USB hub_probe: rework ugly goto-into-compound-statement
On Wed, Nov 09, 2016 at 06:35:21PM +0300, Eugene Korenevsky wrote: > Rework smelling code (goto inside compound statement). Perhaps this is > legacy. Anyway such code is not appropriate for Linux kernel. > > Changes since v3: fix typo > Changes since v2: extract the code to static function > Changes since v1: fix spaces instead of tab, add missing 'Signed-off-by' changes go below the --- line, please read Documentation/SubmittingPatches for all of the details. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v4] USB hub_probe: rework ugly goto-into-compound-statement
Hi,
On 9 November 2016 at 23:35, Eugene Korenevsky wrote:
> Rework smelling code (goto inside compound statement). Perhaps this is
> legacy. Anyway such code is not appropriate for Linux kernel.
>
> Changes since v3: fix typo
> Changes since v2: extract the code to static function
> Changes since v1: fix spaces instead of tab, add missing 'Signed-off-by'
>
> Signed-off-by: Eugene Korenevsky
> ---
> drivers/usb/core/hub.c | 35 ++-
> 1 file changed, 18 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index cbb1467..b770c8d 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -1722,10 +1722,25 @@ static void hub_disconnect(struct usb_interface *intf)
> kref_put(&hub->kref, hub_release);
> }
>
> +static int hub_check_descriptor_sanity(struct usb_host_interface *desc)
> +{
> + /* Some hubs have a subclass of 1, which AFAICT according to the */
> + /* specs is not defined, but it works */
> + if (desc->desc.bInterfaceSubClass != 0 &&
> + desc->desc.bInterfaceSubClass != 1)
> + return 0;
> +
> + /* Multiple endpoints? What kind of mutant ninja-hub is this? */
> + if (desc->desc.bNumEndpoints != 1)
> + return 0;
We usually return 0 as successful result, can you return kernel error
number if we check the descriptor failed? Or change the return value
of the function as bool type.
> +
> + /* If it's not an interrupt in endpoint, we'd better punt! */
> + return usb_endpoint_is_int_in(&desc->endpoint[0].desc);
> +}
> +
> static int hub_probe(struct usb_interface *intf, const struct usb_device_id
> *id)
> {
> struct usb_host_interface *desc;
> - struct usb_endpoint_descriptor *endpoint;
> struct usb_device *hdev;
> struct usb_hub *hub;
>
> @@ -1800,25 +1815,11 @@ static int hub_probe(struct usb_interface *intf,
> const struct usb_device_id *id)
> }
> #endif
>
> - /* Some hubs have a subclass of 1, which AFAICT according to the */
> - /* specs is not defined, but it works */
> - if ((desc->desc.bInterfaceSubClass != 0) &&
> - (desc->desc.bInterfaceSubClass != 1)) {
> -descriptor_error:
> + if (!hub_check_descriptor_sanity(desc)) {
> dev_err(&intf->dev, "bad descriptor, ignoring hub\n");
> return -EIO;
> }
>
> - /* Multiple endpoints? What kind of mutant ninja-hub is this? */
> - if (desc->desc.bNumEndpoints != 1)
> - goto descriptor_error;
> -
> - endpoint = &desc->endpoint[0].desc;
> -
> - /* If it's not an interrupt in endpoint, we'd better punt! */
> - if (!usb_endpoint_is_int_in(endpoint))
> - goto descriptor_error;
> -
> /* We found a hub */
> dev_info(&intf->dev, "USB hub found\n");
>
> @@ -1845,7 +1846,7 @@ static int hub_probe(struct usb_interface *intf, const
> struct usb_device_id *id)
> if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
> hub->quirk_check_port_auto_suspend = 1;
>
> - if (hub_configure(hub, endpoint) >= 0)
> + if (hub_configure(hub, &desc->endpoint[0].desc) >= 0)
> return 0;
>
> hub_disconnect(intf);
> --
> 2.10.2
>
>
> --
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--
Baolin.wang
Best Regards
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[PATCH v4] USB hub_probe: rework ugly goto-into-compound-statement
Rework smelling code (goto inside compound statement). Perhaps this is
legacy. Anyway such code is not appropriate for Linux kernel.
Changes since v3: fix typo
Changes since v2: extract the code to static function
Changes since v1: fix spaces instead of tab, add missing 'Signed-off-by'
Signed-off-by: Eugene Korenevsky
---
drivers/usb/core/hub.c | 35 ++-
1 file changed, 18 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index cbb1467..b770c8d 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1722,10 +1722,25 @@ static void hub_disconnect(struct usb_interface *intf)
kref_put(&hub->kref, hub_release);
}
+static int hub_check_descriptor_sanity(struct usb_host_interface *desc)
+{
+ /* Some hubs have a subclass of 1, which AFAICT according to the */
+ /* specs is not defined, but it works */
+ if (desc->desc.bInterfaceSubClass != 0 &&
+ desc->desc.bInterfaceSubClass != 1)
+ return 0;
+
+ /* Multiple endpoints? What kind of mutant ninja-hub is this? */
+ if (desc->desc.bNumEndpoints != 1)
+ return 0;
+
+ /* If it's not an interrupt in endpoint, we'd better punt! */
+ return usb_endpoint_is_int_in(&desc->endpoint[0].desc);
+}
+
static int hub_probe(struct usb_interface *intf, const struct usb_device_id
*id)
{
struct usb_host_interface *desc;
- struct usb_endpoint_descriptor *endpoint;
struct usb_device *hdev;
struct usb_hub *hub;
@@ -1800,25 +1815,11 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
}
#endif
- /* Some hubs have a subclass of 1, which AFAICT according to the */
- /* specs is not defined, but it works */
- if ((desc->desc.bInterfaceSubClass != 0) &&
- (desc->desc.bInterfaceSubClass != 1)) {
-descriptor_error:
+ if (!hub_check_descriptor_sanity(desc)) {
dev_err(&intf->dev, "bad descriptor, ignoring hub\n");
return -EIO;
}
- /* Multiple endpoints? What kind of mutant ninja-hub is this? */
- if (desc->desc.bNumEndpoints != 1)
- goto descriptor_error;
-
- endpoint = &desc->endpoint[0].desc;
-
- /* If it's not an interrupt in endpoint, we'd better punt! */
- if (!usb_endpoint_is_int_in(endpoint))
- goto descriptor_error;
-
/* We found a hub */
dev_info(&intf->dev, "USB hub found\n");
@@ -1845,7 +1846,7 @@ static int hub_probe(struct usb_interface *intf, const
struct usb_device_id *id)
if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
hub->quirk_check_port_auto_suspend = 1;
- if (hub_configure(hub, endpoint) >= 0)
+ if (hub_configure(hub, &desc->endpoint[0].desc) >= 0)
return 0;
hub_disconnect(intf);
--
2.10.2
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