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Subject[PATCH v6] 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.

Signed-off-by: Eugene Korenevsky <ekorenevsky@gmail.com>
---
Changes in v6: more pedantic conversion from `int` to `bool`; fix comment
Changes in v5: make `bool` a return type of `hub_check_descriptor_sanity()`
Changes in v4: fix typo
Changes in v3: extract the code to static function
Changes in v2: fix spaces instead of tab, add missing 'Signed-off-by'

drivers/usb/core/hub.c | 38 +++++++++++++++++++++-----------------
1 file changed, 21 insertions(+), 17 deletions(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index cbb1467..dbebfe4 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1722,10 +1722,28 @@ static void hub_disconnect(struct usb_interface *intf)
kref_put(&hub->kref, hub_release);
}

+static bool 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 false;
+
+ /* Multiple endpoints? What kind of mutant ninja-hub is this? */
+ if (desc->desc.bNumEndpoints != 1)
+ return false;
+
+ /* If the first endpoint is not interrupt IN, we'd better punt! */
+ if (!usb_endpoint_is_int_in(&desc->endpoint[0].desc))
+ return false;
+
+ return true;
+}
+
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 +1818,11 @@ 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 +1849,7 @@ 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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