From e90a6df80dc45ab53d2f4f4db297434e48c0208e Mon Sep 17 00:00:00 2001 From: Henrik Rydberg Date: Mon, 25 Feb 2013 11:31:43 +0100 Subject: HID: Extend the interface with report requests Some drivers send reports directly to underlying device, creating an unwanted dependency on the underlying transport layer. This patch adds hid_hw_request() to the interface, thereby removing usbhid from the lion share of the drivers. Signed-off-by: Henrik Rydberg Signed-off-by: Benjamin Tissoires Reviewed-by: Mika Westerberg Signed-off-by: Jiri Kosina --- include/linux/hid.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'include/linux/hid.h') diff --git a/include/linux/hid.h b/include/linux/hid.h index e14b465b1146..261c713d4842 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -662,6 +662,7 @@ struct hid_driver { * @hidinput_input_event: event input event (e.g. ff or leds) * @parse: this method is called only once to parse the device data, * shouldn't allocate anything to not leak memory + * @request: send report request to device (e.g. feature report) */ struct hid_ll_driver { int (*start)(struct hid_device *hdev); @@ -676,6 +677,10 @@ struct hid_ll_driver { unsigned int code, int value); int (*parse)(struct hid_device *hdev); + + void (*request)(struct hid_device *hdev, + struct hid_report *report, int reqtype); + }; #define PM_HINT_FULLON 1<<5 @@ -883,6 +888,21 @@ static inline int hid_hw_power(struct hid_device *hdev, int level) return hdev->ll_driver->power ? hdev->ll_driver->power(hdev, level) : 0; } + +/** + * hid_hw_request - send report request to device + * + * @hdev: hid device + * @report: report to send + * @reqtype: hid request type + */ +static inline void hid_hw_request(struct hid_device *hdev, + struct hid_report *report, int reqtype) +{ + if (hdev->ll_driver->request) + hdev->ll_driver->request(hdev, report, reqtype); +} + int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, int size, int interrupt); -- cgit v1.2.2 From 3373443befa73ee60e4275e7699b26058b01455a Mon Sep 17 00:00:00 2001 From: Henrik Rydberg Date: Mon, 25 Feb 2013 11:31:44 +0100 Subject: HID: Extend the interface with wait io request Some drivers need to wait for an io from the underlying device, creating an unwanted dependency on the underlying transport layer. This patch adds wait() to the interface, thereby removing usbhid from the lion share of the drivers. Signed-off-by: Henrik Rydberg Signed-off-by: Benjamin Tissoires Reviewed-by: Mika Westerberg Signed-off-by: Jiri Kosina --- include/linux/hid.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'include/linux/hid.h') diff --git a/include/linux/hid.h b/include/linux/hid.h index 261c713d4842..7071eb3d36c7 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -663,6 +663,7 @@ struct hid_driver { * @parse: this method is called only once to parse the device data, * shouldn't allocate anything to not leak memory * @request: send report request to device (e.g. feature report) + * @wait: wait for buffered io to complete (send/recv reports) */ struct hid_ll_driver { int (*start)(struct hid_device *hdev); @@ -681,6 +682,8 @@ struct hid_ll_driver { void (*request)(struct hid_device *hdev, struct hid_report *report, int reqtype); + int (*wait)(struct hid_device *hdev); + }; #define PM_HINT_FULLON 1<<5 @@ -903,6 +906,17 @@ static inline void hid_hw_request(struct hid_device *hdev, hdev->ll_driver->request(hdev, report, reqtype); } +/** + * hid_hw_wait - wait for buffered io to complete + * + * @hdev: hid device + */ +static inline void hid_hw_wait(struct hid_device *hdev) +{ + if (hdev->ll_driver->wait) + hdev->ll_driver->wait(hdev); +} + int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, int size, int interrupt); -- cgit v1.2.2 From c849a6143bec520aff2a6646518b0d041402428b Mon Sep 17 00:00:00 2001 From: Andrew de los Reyes Date: Mon, 18 Feb 2013 09:20:21 -0800 Subject: HID: Separate struct hid_device's driver_lock into two locks. This patch separates struct hid_device's driver_lock into two. The goal is to allow hid device drivers to receive input during their probe() or remove() function calls. This is necessary because some drivers need to communicate with the device to determine parameters needed during probe (e.g., size of a multi-touch surface), and if possible, may perfer to communicate with a device on host-initiated disconnect (e.g., to put it into a low-power state). Historically, three functions used driver_lock: - hid_device_probe: blocks to acquire lock - hid_device_remove: blocks to acquire lock - hid_input_report: if locked returns -EBUSY, else acquires lock This patch adds another lock (driver_input_lock) which is used to block input from occurring. The lock behavior is now: - hid_device_probe: blocks to acq. driver_lock, then driver_input_lock - hid_device_remove: blocks to acq. driver_lock, then driver_input_lock - hid_input_report: if driver_input_lock locked returns -EBUSY, else acquires driver_input_lock This patch also adds two helper functions to be called during probe() or remove(): hid_device_io_start() and hid_device_io_stop(). These functions lock and unlock, respectively, driver_input_lock; they also make a note of whether they did so that hid-core knows if a driver has changed the lock state. This patch results in no behavior change for existing devices and drivers. However, during a probe() or remove() function call in a driver, that driver may now selectively call hid_device_io_start() to let input events come through, then optionally call hid_device_io_stop() to stop them. Signed-off-by: Andrew de los Reyes Signed-off-by: Jiri Kosina --- include/linux/hid.h | 46 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 45 insertions(+), 1 deletion(-) (limited to 'include/linux/hid.h') diff --git a/include/linux/hid.h b/include/linux/hid.h index e14b465b1146..895b85639dec 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -456,7 +456,8 @@ struct hid_device { /* device report descriptor */ unsigned country; /* HID country */ struct hid_report_enum report_enum[HID_REPORT_TYPES]; - struct semaphore driver_lock; /* protects the current driver */ + struct semaphore driver_lock; /* protects the current driver, except during input */ + struct semaphore driver_input_lock; /* protects the current driver */ struct device dev; /* device */ struct hid_driver *driver; struct hid_ll_driver *ll_driver; @@ -477,6 +478,7 @@ struct hid_device { /* device report descriptor */ unsigned int status; /* see STAT flags above */ unsigned claimed; /* Claimed by hidinput, hiddev? */ unsigned quirks; /* Various quirks the device can pull on us */ + bool io_started; /* Protected by driver_lock. If IO has started */ struct list_head inputs; /* The list of inputs */ void *hiddev; /* The hiddev structure */ @@ -599,6 +601,10 @@ struct hid_usage_id { * @resume: invoked on resume if device was not reset (NULL means nop) * @reset_resume: invoked on resume if device was reset (NULL means nop) * + * probe should return -errno on error, or 0 on success. During probe, + * input will not be passed to raw_event unless hid_device_io_start is + * called. + * * raw_event and event should return 0 on no action performed, 1 when no * further processing should be done and negative on error * @@ -737,6 +743,44 @@ const struct hid_device_id *hid_match_id(struct hid_device *hdev, const struct hid_device_id *id); s32 hid_snto32(__u32 value, unsigned n); +/** + * hid_device_io_start - enable HID input during probe, remove + * + * @hid - the device + * + * This should only be called during probe or remove and only be + * called by the thread calling probe or remove. It will allow + * incoming packets to be delivered to the driver. + */ +static inline void hid_device_io_start(struct hid_device *hid) { + if (hid->io_started) { + dev_warn(&hid->dev, "io already started"); + return; + } + hid->io_started = true; + up(&hid->driver_input_lock); +} + +/** + * hid_device_io_stop - disable HID input during probe, remove + * + * @hid - the device + * + * Should only be called after hid_device_io_start. It will prevent + * incoming packets from going to the driver for the duration of + * probe, remove. If called during probe, packets will still go to the + * driver after probe is complete. This function should only be called + * by the thread calling probe or remove. + */ +static inline void hid_device_io_stop(struct hid_device *hid) { + if (!hid->io_started) { + dev_warn(&hid->dev, "io already stopped"); + return; + } + hid->io_started = false; + down(&hid->driver_input_lock); +} + /** * hid_map_usage - map usage input bits * -- cgit v1.2.2 From 9684819b5a29e62acd8265a92d8f3454de9bb71e Mon Sep 17 00:00:00 2001 From: Benjamin Tissoires Date: Wed, 27 Feb 2013 16:38:17 +0100 Subject: HID: ll_driver: Extend the interface with idle requests Some drivers send the idle command directly to underlying device, creating an unwanted dependency on the underlying transport layer. This patch adds hid_hw_idle() to the interface, thereby removing usbhid from the lion share of the drivers. Signed-off-by: Benjamin Tissoires Reviewed-by: David Herrmann Signed-off-by: Jiri Kosina --- include/linux/hid.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'include/linux/hid.h') diff --git a/include/linux/hid.h b/include/linux/hid.h index 7071eb3d36c7..863744c38ddc 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -664,6 +664,7 @@ struct hid_driver { * shouldn't allocate anything to not leak memory * @request: send report request to device (e.g. feature report) * @wait: wait for buffered io to complete (send/recv reports) + * @idle: send idle request to device */ struct hid_ll_driver { int (*start)(struct hid_device *hdev); @@ -683,6 +684,7 @@ struct hid_ll_driver { struct hid_report *report, int reqtype); int (*wait)(struct hid_device *hdev); + int (*idle)(struct hid_device *hdev, int report, int idle, int reqtype); }; @@ -906,6 +908,23 @@ static inline void hid_hw_request(struct hid_device *hdev, hdev->ll_driver->request(hdev, report, reqtype); } +/** + * hid_hw_idle - send idle request to device + * + * @hdev: hid device + * @report: report to control + * @idle: idle state + * @reqtype: hid request type + */ +static inline int hid_hw_idle(struct hid_device *hdev, int report, int idle, + int reqtype) +{ + if (hdev->ll_driver->idle) + return hdev->ll_driver->idle(hdev, report, idle, reqtype); + + return 0; +} + /** * hid_hw_wait - wait for buffered io to complete * -- cgit v1.2.2 From 4f22decf9b6329acfe59091c5cba6b378b9b31db Mon Sep 17 00:00:00 2001 From: Benjamin Tissoires Date: Fri, 22 Mar 2013 18:38:28 +0100 Subject: HID: input: don't register unmapped input devices There is no need to register an input device containing no events. This allows drivers using the quirk MULTI_INPUT to register one input per report effectively used. For backward compatibility, we need to add a quirk to request this behavior. Signed-off-by: Benjamin Tissoires Signed-off-by: Jiri Kosina --- include/linux/hid.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/hid.h') diff --git a/include/linux/hid.h b/include/linux/hid.h index 863744c38ddc..fffa06bc4880 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -282,6 +282,7 @@ struct hid_item { #define HID_QUIRK_BADPAD 0x00000020 #define HID_QUIRK_MULTI_INPUT 0x00000040 #define HID_QUIRK_HIDINPUT_FORCE 0x00000080 +#define HID_QUIRK_NO_EMPTY_INPUT 0x00000100 #define HID_QUIRK_SKIP_OUTPUT_REPORTS 0x00010000 #define HID_QUIRK_FULLSPEED_INTERVAL 0x10000000 #define HID_QUIRK_NO_INIT_REPORTS 0x20000000 -- cgit v1.2.2 From 2353f2bea307390e015493118e425152b8a5a431 Mon Sep 17 00:00:00 2001 From: Jiri Kosina Date: Tue, 16 Apr 2013 15:40:09 -0700 Subject: HID: protect hid_debug_list Accesses to hid_device->hid_debug_list are not serialized properly, which could result in SMP concurrency issues when HID debugfs events are accessesed by multiple userspace processess. Serialize all the list operations by a mutex. Spotted by Al Viro. Signed-off-by: Jiri Kosina --- include/linux/hid.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/hid.h') diff --git a/include/linux/hid.h b/include/linux/hid.h index e14b465b1146..06579c72d195 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -512,6 +512,7 @@ struct hid_device { /* device report descriptor */ struct dentry *debug_rdesc; struct dentry *debug_events; struct list_head debug_list; + struct mutex debug_list_lock; wait_queue_head_t debug_wait; }; -- cgit v1.2.2 From 1deb9d341d475ff84262e927d6c0e36fecb9942e Mon Sep 17 00:00:00 2001 From: Jiri Kosina Date: Mon, 6 May 2013 13:05:50 +0200 Subject: HID: debug: fix RCU preemption issue Commit 2353f2bea ("HID: protect hid_debug_list") introduced mutex locking around debug_list access to prevent SMP races when debugfs nodes are being operated upon by multiple userspace processess. mutex is not a proper synchronization primitive though, as the hid-debug callbacks are being called from atomic contexts. We also have to be careful about disabling IRQs when taking the lock to prevent deadlock against IRQ handlers. Benjamin reports this has also been reported in RH bugzilla as bug #958935. =============================== [ INFO: suspicious RCU usage. ] 3.9.0+ #94 Not tainted ------------------------------- include/linux/rcupdate.h:476 Illegal context switch in RCU read-side critical section! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 4 locks held by Xorg/5502: #0: (&evdev->mutex){+.+...}, at: [] evdev_write+0x6d/0x160 #1: (&(&dev->event_lock)->rlock#2){-.-...}, at: [] input_inject_event+0x5b/0x230 #2: (rcu_read_lock){.+.+..}, at: [] input_inject_event+0x42/0x230 #3: (&(&usbhid->lock)->rlock){-.....}, at: [] usb_hidinput_input_event+0x89/0x120 stack backtrace: CPU: 0 PID: 5502 Comm: Xorg Not tainted 3.9.0+ #94 Hardware name: Dell Inc. OptiPlex 390/0M5DCD, BIOS A09 07/24/2012 0000000000000001 ffff8800689c7c38 ffffffff816f249f ffff8800689c7c68 ffffffff810acb1d 0000000000000000 ffffffff81a03ac7 000000000000019d 0000000000000000 ffff8800689c7c90 ffffffff8107cda7 0000000000000000 Call Trace: [] dump_stack+0x19/0x1b [] lockdep_rcu_suspicious+0xfd/0x130 [] __might_sleep+0xc7/0x230 [] mutex_lock_nested+0x40/0x3a0 [] ? vsnprintf+0x354/0x640 [] hid_debug_event+0x34/0x100 [] hid_dump_input+0x67/0xa0 [] hid_set_field+0x50/0x120 [] usb_hidinput_input_event+0x9a/0x120 [] input_handle_event+0x8e/0x530 [] input_inject_event+0x1d0/0x230 [] ? input_inject_event+0x42/0x230 [] evdev_write+0xde/0x160 [] vfs_write+0xc8/0x1f0 [] SyS_write+0x55/0xa0 [] system_call_fastpath+0x16/0x1b BUG: sleeping function called from invalid context at kernel/mutex.c:413 in_atomic(): 1, irqs_disabled(): 1, pid: 5502, name: Xorg INFO: lockdep is turned off. irq event stamp: 1098574 hardirqs last enabled at (1098573): [] _raw_spin_unlock_irqrestore+0x3f/0x70 hardirqs last disabled at (1098574): [] _raw_spin_lock_irqsave+0x25/0xa0 softirqs last enabled at (1098306): [] __do_softirq+0x18f/0x3c0 softirqs last disabled at (1097867): [] irq_exit+0xa5/0xb0 CPU: 0 PID: 5502 Comm: Xorg Not tainted 3.9.0+ #94 Hardware name: Dell Inc. OptiPlex 390/0M5DCD, BIOS A09 07/24/2012 ffffffff81a03ac7 ffff8800689c7c68 ffffffff816f249f ffff8800689c7c90 ffffffff8107ce60 0000000000000000 ffff8800689c7fd8 ffff88006a62c800 ffff8800689c7d10 ffffffff816f7770 ffff8800689c7d00 ffffffff81312ac4 Call Trace: [] dump_stack+0x19/0x1b [] __might_sleep+0x180/0x230 [] mutex_lock_nested+0x40/0x3a0 [] ? vsnprintf+0x354/0x640 [] hid_debug_event+0x34/0x100 [] hid_dump_input+0x67/0xa0 [] hid_set_field+0x50/0x120 [] usb_hidinput_input_event+0x9a/0x120 [] input_handle_event+0x8e/0x530 [] input_inject_event+0x1d0/0x230 [] ? input_inject_event+0x42/0x230 [] evdev_write+0xde/0x160 [] vfs_write+0xc8/0x1f0 [] SyS_write+0x55/0xa0 [] system_call_fastpath+0x16/0x1b Reported-by: majianpeng Reported-by: Benjamin Tissoires Reviewed-by: Dmitry Torokhov Signed-off-by: Jiri Kosina --- include/linux/hid.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/hid.h') diff --git a/include/linux/hid.h b/include/linux/hid.h index af1b86d46f6e..0c48991b0402 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -515,7 +515,7 @@ struct hid_device { /* device report descriptor */ struct dentry *debug_rdesc; struct dentry *debug_events; struct list_head debug_list; - struct mutex debug_list_lock; + spinlock_t debug_list_lock; wait_queue_head_t debug_wait; }; -- cgit v1.2.2