From: Johan Hovold Date: Fri, 17 Mar 2017 10:35:31 +0000 (+0100) Subject: USB: core: add helpers to retrieve endpoints in reverse order X-Git-Tag: v4.12-rc1~97^2~83 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=279daf4e053470f22c9421a4ab05f8e5a9e9eeec;p=karo-tx-linux.git USB: core: add helpers to retrieve endpoints in reverse order Several drivers have implemented their endpoint look-up loops in such a way that they have picked the last endpoint descriptor of the specified type should more than one such descriptor exist. To avoid any regressions, add corresponding helpers to lookup endpoints by searching the endpoint descriptors in reverse order. Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index 5d65504770f5..1ec9d248781e 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -74,6 +74,48 @@ MODULE_PARM_DESC(autosuspend, "default autosuspend delay"); #define usb_autosuspend_delay 0 #endif +static bool match_endpoint(struct usb_endpoint_descriptor *epd, + struct usb_endpoint_descriptor **bulk_in, + struct usb_endpoint_descriptor **bulk_out, + struct usb_endpoint_descriptor **int_in, + struct usb_endpoint_descriptor **int_out) +{ + switch (usb_endpoint_type(epd)) { + case USB_ENDPOINT_XFER_BULK: + if (usb_endpoint_dir_in(epd)) { + if (bulk_in && !*bulk_in) { + *bulk_in = epd; + break; + } + } else { + if (bulk_out && !*bulk_out) { + *bulk_out = epd; + break; + } + } + + return false; + case USB_ENDPOINT_XFER_INT: + if (usb_endpoint_dir_in(epd)) { + if (int_in && !*int_in) { + *int_in = epd; + break; + } + } else { + if (int_out && !*int_out) { + *int_out = epd; + break; + } + } + + return false; + default: + return false; + } + + return (!bulk_in || *bulk_in) && (!bulk_out || *bulk_out) && + (!int_in || *int_in) && (!int_out || *int_out); +} /** * usb_find_common_endpoints() -- look up common endpoint descriptors @@ -113,50 +155,48 @@ int usb_find_common_endpoints(struct usb_host_interface *alt, for (i = 0; i < alt->desc.bNumEndpoints; ++i) { epd = &alt->endpoint[i].desc; - switch (usb_endpoint_type(epd)) { - case USB_ENDPOINT_XFER_BULK: - if (usb_endpoint_dir_in(epd)) { - if (bulk_in && !*bulk_in) { - *bulk_in = epd; - break; - } - } else { - if (bulk_out && !*bulk_out) { - *bulk_out = epd; - break; - } - } + if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out)) + return 0; + } - continue; - case USB_ENDPOINT_XFER_INT: - if (usb_endpoint_dir_in(epd)) { - if (int_in && !*int_in) { - *int_in = epd; - break; - } - } else { - if (int_out && !*int_out) { - *int_out = epd; - break; - } - } + return -ENXIO; +} +EXPORT_SYMBOL_GPL(usb_find_common_endpoints); - continue; - default: - continue; - } +/** + * usb_find_common_endpoints_reverse() -- look up common endpoint descriptors + * + * Same as usb_find_common_endpoints(), but the endpoint descriptors are + * searched in reverse order (see usb_find_common_endpoints() for details). + */ +int usb_find_common_endpoints_reverse(struct usb_host_interface *alt, + struct usb_endpoint_descriptor **bulk_in, + struct usb_endpoint_descriptor **bulk_out, + struct usb_endpoint_descriptor **int_in, + struct usb_endpoint_descriptor **int_out) +{ + struct usb_endpoint_descriptor *epd; + int i; + + if (bulk_in) + *bulk_in = NULL; + if (bulk_out) + *bulk_out = NULL; + if (int_in) + *int_in = NULL; + if (int_out) + *int_out = NULL; + + for (i = alt->desc.bNumEndpoints - 1; i >= 0; --i) { + epd = &alt->endpoint[i].desc; - if ((!bulk_in || *bulk_in) && - (!bulk_out || *bulk_out) && - (!int_in || *int_in) && - (!int_out || *int_out)) { + if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out)) return 0; - } } return -ENXIO; } -EXPORT_SYMBOL_GPL(usb_find_common_endpoints); +EXPORT_SYMBOL_GPL(usb_find_common_endpoints_reverse); /** * usb_find_alt_setting() - Given a configuration, find the alternate setting diff --git a/include/linux/usb.h b/include/linux/usb.h index 7041cc950737..226557362d36 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -106,6 +106,13 @@ usb_find_common_endpoints(struct usb_host_interface *alt, struct usb_endpoint_descriptor **int_in, struct usb_endpoint_descriptor **int_out); +int __must_check +usb_find_common_endpoints_reverse(struct usb_host_interface *alt, + struct usb_endpoint_descriptor **bulk_in, + struct usb_endpoint_descriptor **bulk_out, + struct usb_endpoint_descriptor **int_in, + struct usb_endpoint_descriptor **int_out); + static inline int __must_check usb_find_bulk_in_endpoint(struct usb_host_interface *alt, struct usb_endpoint_descriptor **bulk_in) @@ -134,6 +141,34 @@ usb_find_int_out_endpoint(struct usb_host_interface *alt, return usb_find_common_endpoints(alt, NULL, NULL, NULL, int_out); } +static inline int __must_check +usb_find_last_bulk_in_endpoint(struct usb_host_interface *alt, + struct usb_endpoint_descriptor **bulk_in) +{ + return usb_find_common_endpoints_reverse(alt, bulk_in, NULL, NULL, NULL); +} + +static inline int __must_check +usb_find_last_bulk_out_endpoint(struct usb_host_interface *alt, + struct usb_endpoint_descriptor **bulk_out) +{ + return usb_find_common_endpoints_reverse(alt, NULL, bulk_out, NULL, NULL); +} + +static inline int __must_check +usb_find_last_int_in_endpoint(struct usb_host_interface *alt, + struct usb_endpoint_descriptor **int_in) +{ + return usb_find_common_endpoints_reverse(alt, NULL, NULL, int_in, NULL); +} + +static inline int __must_check +usb_find_last_int_out_endpoint(struct usb_host_interface *alt, + struct usb_endpoint_descriptor **int_out) +{ + return usb_find_common_endpoints_reverse(alt, NULL, NULL, NULL, int_out); +} + /** * struct usb_interface - what usb device drivers talk to * @altsetting: array of interface structures, one for each alternate