From e688355bfeadf17ef522b1e62cc12f8e88e69667 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 6 Feb 2012 19:22:19 +0100 Subject: USB: serial: add macro for console error reporting Add macro which prints an error message only once if port is used a console. Reporting errors in a write path when port is used as a console could otherwise result in an infinite loop. Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- include/linux/usb/serial.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'include/linux/usb/serial.h') diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h index 4267a9c717ba..10cb74d2ad1d 100644 --- a/include/linux/usb/serial.h +++ b/include/linux/usb/serial.h @@ -389,5 +389,20 @@ do { \ printk(KERN_DEBUG "%s: " format "\n", __FILE__, ##arg); \ } while (0) +/* + * Macro for reporting errors in write path to avoid inifinite loop + * when port is used as a console. + */ +#define dev_err_console(usport, fmt, ...) \ +do { \ + static bool __print_once; \ + struct usb_serial_port *__port = (usport); \ + \ + if (!__port->port.console || !__print_once) { \ + __print_once = true; \ + dev_err(&__port->dev, fmt, ##__VA_ARGS__); \ + } \ +} while (0) + #endif /* __LINUX_USB_SERIAL_H */ -- cgit v1.2.3 From 765e0ba62613fb90f09c1b5926750df0aa56f349 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Thu, 23 Feb 2012 14:55:59 -0500 Subject: usb-serial: new API for driver registration This patch (as1522) adds two new routines to the usb-serial core, for registering and unregistering serial drivers. Instead of registering the usb_driver and usb_serial_drivers separately, with error checking for each one, the drivers can all be registered and unregistered by a single function call. This reduces duplicated code. More importantly, the new core routines change the order in which the drivers are registered. Currently the usb-serial drivers are all registered first and the usb_driver is done last, which leaves a window for problems. A udev script may quickly add a new dynamic-ID for a usb-serial driver, causing the corresponding usb_driver to be probed. If the usb_driver hasn't been registered yet then an oops will occur. The new routine prevents such problems by registering the usb_driver first. To insure that it gets probed properly for already-attached serial devices, we call driver_attach() after all the usb-serial drivers have been registered. Along with adding the new routines, the patch modifies the "generic" serial driver to use them. Further patches will similarly modify all the other in-tree USB serial drivers. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- include/linux/usb/serial.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/linux/usb/serial.h') diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h index 10cb74d2ad1d..8c8dbf9c5b89 100644 --- a/include/linux/usb/serial.h +++ b/include/linux/usb/serial.h @@ -300,8 +300,17 @@ struct usb_serial_driver { #define to_usb_serial_driver(d) \ container_of(d, struct usb_serial_driver, driver) +/* + * These two routines are kept only for backward compatibility. + * Don't use them; call usb_serial_{de}register_drivers() instead. + */ extern int usb_serial_register(struct usb_serial_driver *driver); extern void usb_serial_deregister(struct usb_serial_driver *driver); + +extern int usb_serial_register_drivers(struct usb_driver *udriver, + struct usb_serial_driver * const serial_drivers[]); +extern void usb_serial_deregister_drivers(struct usb_driver *udriver, + struct usb_serial_driver * const serial_drivers[]); extern void usb_serial_port_softint(struct usb_serial_port *port); extern int usb_serial_probe(struct usb_interface *iface, -- cgit v1.2.3 From f799e7678390029e322ae2dc3cda389b11f38124 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Fri, 24 Feb 2012 12:50:30 -0800 Subject: USB: serial: remove usb_serial_register and usb_serial_deregister No one uses them anymore, they should be using the safer usb_serial_register_drivers() and usb_serial_deregister_drivers() functions instead. Thanks to Alan Stern for writing these functions and porting all in-kernel users to them. Cc: Alan Stern Signed-off-by: Greg Kroah-Hartman --- include/linux/usb/serial.h | 7 ------- 1 file changed, 7 deletions(-) (limited to 'include/linux/usb/serial.h') diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h index 8c8dbf9c5b89..34c06a723dcc 100644 --- a/include/linux/usb/serial.h +++ b/include/linux/usb/serial.h @@ -300,13 +300,6 @@ struct usb_serial_driver { #define to_usb_serial_driver(d) \ container_of(d, struct usb_serial_driver, driver) -/* - * These two routines are kept only for backward compatibility. - * Don't use them; call usb_serial_{de}register_drivers() instead. - */ -extern int usb_serial_register(struct usb_serial_driver *driver); -extern void usb_serial_deregister(struct usb_serial_driver *driver); - extern int usb_serial_register_drivers(struct usb_driver *udriver, struct usb_serial_driver * const serial_drivers[]); extern void usb_serial_deregister_drivers(struct usb_driver *udriver, -- cgit v1.2.3 From d1cddb4a8e9b09c33158acae05c48069d74fa4d0 Mon Sep 17 00:00:00 2001 From: Greg KH Date: Fri, 24 Feb 2012 15:38:14 -0800 Subject: USB: create module_usb_serial_driver macro Now that Alan Stern has cleaned up the usb serial driver registration, we have the ability to create a module_usb_serial_driver macro to make things a bit simpler, like the other *_driver macros created. But, as we need two functions here, we can't reuse the existing module_driver() macro, so we need to roll our own. Here's a patch implementing module_usb_serial_driver() and it converts the pl2303 driver to use it, showing a nice cleanup. Signed-off-by: Greg Kroah-Hartman --- include/linux/usb/serial.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'include/linux/usb/serial.h') diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h index 34c06a723dcc..7b1db841e2a8 100644 --- a/include/linux/usb/serial.h +++ b/include/linux/usb/serial.h @@ -406,5 +406,33 @@ do { \ } \ } while (0) +/* + * module_usb_serial_driver() - Helper macro for registering a USB Serial driver + * @__usb_driver: usb_driver struct to register + * @__serial_drivers: list of usb_serial drivers to register + * + * Helper macro for USB serial drivers which do not do anything special + * in module init/exit. This eliminates a lot of boilerplate. Each + * module may only use this macro once, and calling it replaces + * module_init() and module_exit() + * + * Note, we can't use the generic module_driver() call here, due to the + * two parameters in the usb_serial_* functions, so we roll our own here + * :( + */ +#define module_usb_serial_driver(__usb_driver, __serial_drivers) \ +static int __init usb_serial_driver_init(void) \ +{ \ + return usb_serial_register_drivers(&(__usb_driver), \ + (__serial_drivers)); \ +} \ +module_init(usb_serial_driver_init); \ +static void __exit usb_serial_driver_exit(void) \ +{ \ + return usb_serial_deregister_drivers(&(__usb_driver), \ + (__serial_drivers)); \ +} \ +module_exit(usb_serial_driver_exit); + #endif /* __LINUX_USB_SERIAL_H */ -- cgit v1.2.3 From b790f5d1260b4c962bd066cd34ae982943c27fe1 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Fri, 9 Mar 2012 16:38:14 -0800 Subject: USB: serial: use module_driver() macro Now that module_driver() can handle varargs, use it instead of rolling our own version. Cc: Lars-Peter Clausen Signed-off-by: Greg Kroah-Hartman --- include/linux/usb/serial.h | 17 ++--------------- 1 file changed, 2 insertions(+), 15 deletions(-) (limited to 'include/linux/usb/serial.h') diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h index 7b1db841e2a8..fbb666b1b670 100644 --- a/include/linux/usb/serial.h +++ b/include/linux/usb/serial.h @@ -416,23 +416,10 @@ do { \ * module may only use this macro once, and calling it replaces * module_init() and module_exit() * - * Note, we can't use the generic module_driver() call here, due to the - * two parameters in the usb_serial_* functions, so we roll our own here - * :( */ #define module_usb_serial_driver(__usb_driver, __serial_drivers) \ -static int __init usb_serial_driver_init(void) \ -{ \ - return usb_serial_register_drivers(&(__usb_driver), \ - (__serial_drivers)); \ -} \ -module_init(usb_serial_driver_init); \ -static void __exit usb_serial_driver_exit(void) \ -{ \ - return usb_serial_deregister_drivers(&(__usb_driver), \ - (__serial_drivers)); \ -} \ -module_exit(usb_serial_driver_exit); + module_driver(__usb_driver, usb_serial_register_drivers, \ + usb_serial_deregister_drivers, __serial_drivers) #endif /* __LINUX_USB_SERIAL_H */ -- cgit v1.2.3