diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c index 36382d782e20..bf745e03f21e 100644 --- a/drivers/misc/mei/interrupt.c +++ b/drivers/misc/mei/interrupt.c @@ -209,6 +209,9 @@ static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb, int slots; int ret; + if (!list_empty(&cl->rd_pending)) + return 0; + msg_slots = mei_data2slots(sizeof(struct hbm_flow_control)); slots = mei_hbuf_empty_slots(dev); diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c index d698ba32357c..650061b6ab9b 100644 --- a/drivers/misc/mei/main.c +++ b/drivers/misc/mei/main.c @@ -139,9 +139,8 @@ static ssize_t mei_read(struct file *file, char __user *ubuf, struct mei_cl *cl = file->private_data; struct mei_device *dev; struct mei_cl_cb *cb = NULL; + bool nonblock = !!(file->f_flags & O_NONBLOCK); int rets; - int err; - if (WARN_ON(!cl || !cl->dev)) return -ENODEV; @@ -177,25 +176,29 @@ static ssize_t mei_read(struct file *file, char __user *ubuf, if (*offset > 0) *offset = 0; - err = mei_cl_read_start(cl, length, file); - if (err && err != -EBUSY) { - cl_dbg(dev, cl, "mei start read failure status = %d\n", err); - rets = err; + rets = mei_cl_read_start(cl, length, file); + if (rets && rets != -EBUSY) { + cl_dbg(dev, cl, "mei start read failure status = %d\n", rets); goto out; } - /* synchronized under device mutex */ - if (!waitqueue_active(&cl->rx_wait)) { - if (file->f_flags & O_NONBLOCK) { - rets = -EAGAIN; - goto out; - } + if (nonblock) { + rets = -EAGAIN; + goto out; + } + if (rets == -EBUSY && + !mei_cl_enqueue_ctrl_wr_cb(cl, length, MEI_FOP_READ, file)) { + rets = -ENOMEM; + goto out; + } + + do { mutex_unlock(&dev->device_lock); if (wait_event_interruptible(cl->rx_wait, - (!list_empty(&cl->rd_completed)) || - (!mei_cl_is_connected(cl)))) { + (!list_empty(&cl->rd_completed)) || + (!mei_cl_is_connected(cl)))) { if (signal_pending(current)) return -EINTR; @@ -207,13 +210,9 @@ static ssize_t mei_read(struct file *file, char __user *ubuf, rets = -ENODEV; goto out; } - } - cb = mei_cl_read_cb(cl, file); - if (!cb) { - rets = 0; - goto out; - } + cb = mei_cl_read_cb(cl, file); + } while (!cb); copy_buffer: /* now copy the data to user space */