From e1d67aa40ff1d2d75d526da6b5bbc77559b4690c Mon Sep 17 00:00:00 2001 From: Peter Mamonov Date: Wed, 14 Oct 2015 13:15:49 +0300 Subject: usb: core: return -EAGAIN on usb_* functions reentrance Signed-off-by: Peter Mamonov Signed-off-by: Sascha Hauer --- drivers/usb/core/usb.c | 40 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 39 insertions(+), 1 deletion(-) (limited to 'drivers/usb/core') diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index a3fb1e8808..ce229f2fcc 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -84,10 +84,25 @@ static void print_usb_device(struct usb_device *dev) static int host_busnum = 1; +static inline int usb_host_acquire(struct usb_host *host) +{ + if (host->sem) + return -EAGAIN; + host->sem++; + return 0; +} + +static inline void usb_host_release(struct usb_host *host) +{ + if (host->sem > 0) + host->sem--; +} + int usb_register_host(struct usb_host *host) { list_add_tail(&host->list, &host_list); host->busnum = host_busnum++; + host->sem = 0; asynch_allowed = 1; return 0; } @@ -563,8 +578,17 @@ int usb_submit_int_msg(struct usb_device *dev, unsigned long pipe, void *buffer, int transfer_len, int interval) { struct usb_host *host = dev->host; + int ret; + + ret = usb_host_acquire(host); + if (ret) + return ret; + + ret = host->submit_int_msg(dev, pipe, buffer, transfer_len, interval); - return host->submit_int_msg(dev, pipe, buffer, transfer_len, interval); + usb_host_release(host); + + return ret; } /* @@ -590,6 +614,10 @@ int usb_control_msg(struct usb_device *dev, unsigned int pipe, return -1; } + ret = usb_host_acquire(host); + if (ret) + return ret; + /* set setup command */ setup_packet->requesttype = requesttype; setup_packet->request = request; @@ -603,6 +631,9 @@ int usb_control_msg(struct usb_device *dev, unsigned int pipe, ret = host->submit_control_msg(dev, pipe, data, size, setup_packet, timeout); + + usb_host_release(host); + if (ret) return ret; @@ -623,8 +654,15 @@ int usb_bulk_msg(struct usb_device *dev, unsigned int pipe, if (len < 0) return -1; + ret = usb_host_acquire(host); + if (ret) + return ret; + dev->status = USB_ST_NOT_PROC; /* not yet processed */ ret = host->submit_bulk_msg(dev, pipe, data, len, timeout); + + usb_host_release(host); + if (ret) return ret; -- cgit v1.2.3