Insert markers in console stream marking places where data is missing. This makes the hole in the data stand out clearly instead of glueing together unrelated messages. Signed-off-by: Michał Mirosław <mirq-linux@xxxxxxxxxxxx> --- v2: commit message massage --- drivers/usb/gadget/function/u_serial.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c index 604e187fadb7..66518aba58c2 100644 --- a/drivers/usb/gadget/function/u_serial.c +++ b/drivers/usb/gadget/function/u_serial.c @@ -88,6 +88,7 @@ struct gs_console { spinlock_t lock; struct usb_request *req; struct kfifo buf; + size_t missed; }; /* @@ -930,6 +931,15 @@ static void __gs_console_push(struct gs_console *cons) if (!size) return; + if (cons->missed && ep->maxpacket >= 64) { + char buf[64]; + size_t len; + + len = sprintf(buf, "\n[MISSED %zu bytes]\n", cons->missed); + kfifo_in(&cons->buf, buf, len); + cons->missed = 0; + } + req->length = size; if (usb_ep_queue(ep, req, GFP_ATOMIC)) req->length = 0; @@ -951,10 +961,13 @@ static void gs_console_write(struct console *co, { struct gs_console *cons = container_of(co, struct gs_console, console); unsigned long flags; + size_t n; spin_lock_irqsave(&cons->lock, flags); - kfifo_in(&cons->buf, buf, count); + n = kfifo_in(&cons->buf, buf, count); + if (n < count) + cons->missed += count - n; if (cons->req && !cons->req->length) schedule_work(&cons->work); -- 2.20.1