From b1a31a5f5f27ff8aba42b545a1c721941f735107 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 21 Dec 2017 11:42:04 +0100 Subject: [PATCH] usb/gadget/NCM: Replace tasklet with softirq hrtimer The tx_tasklet tasklet is used in invoke the hrtimer (task_timer) in softirq context. This can be also achieved without the tasklet but with HRTIMER_MODE_SOFT as hrtimer mode. Signed-off-by: Thomas Gleixner Signed-off-by: Anna-Maria Gleixner Acked-by: Felipe Balbi Cc: Christoph Hellwig Cc: Felipe Balbi Cc: John Stultz Cc: Linus Torvalds Cc: Peter Zijlstra Cc: keescook@chromium.org Cc: linux-usb@vger.kernel.org Link: http://lkml.kernel.org/r/20171221104205.7269-36-anna-maria@linutronix.de Signed-off-by: Ingo Molnar --- drivers/usb/gadget/function/f_ncm.c | 30 +++++++---------------------- 1 file changed, 7 insertions(+), 23 deletions(-) diff --git a/drivers/usb/gadget/function/f_ncm.c b/drivers/usb/gadget/function/f_ncm.c index c5bce8e22983..5780fba620ab 100644 --- a/drivers/usb/gadget/function/f_ncm.c +++ b/drivers/usb/gadget/function/f_ncm.c @@ -73,9 +73,7 @@ struct f_ncm { struct sk_buff *skb_tx_ndp; u16 ndp_dgram_count; bool timer_force_tx; - struct tasklet_struct tx_tasklet; struct hrtimer task_timer; - bool timer_stopping; }; @@ -1104,7 +1102,7 @@ static struct sk_buff *ncm_wrap_ntb(struct gether *port, /* Delay the timer. */ hrtimer_start(&ncm->task_timer, TX_TIMEOUT_NSECS, - HRTIMER_MODE_REL); + HRTIMER_MODE_REL_SOFT); /* Add the datagram position entries */ ntb_ndp = skb_put_zero(ncm->skb_tx_ndp, dgram_idx_len); @@ -1148,17 +1146,15 @@ static struct sk_buff *ncm_wrap_ntb(struct gether *port, } /* - * This transmits the NTB if there are frames waiting. + * The transmit should only be run if no skb data has been sent + * for a certain duration. */ -static void ncm_tx_tasklet(unsigned long data) +static enum hrtimer_restart ncm_tx_timeout(struct hrtimer *data) { - struct f_ncm *ncm = (void *)data; - - if (ncm->timer_stopping) - return; + struct f_ncm *ncm = container_of(data, struct f_ncm, task_timer); /* Only send if data is available. */ - if (ncm->skb_tx_data) { + if (!ncm->timer_stopping && ncm->skb_tx_data) { ncm->timer_force_tx = true; /* XXX This allowance of a NULL skb argument to ndo_start_xmit @@ -1171,16 +1167,6 @@ static void ncm_tx_tasklet(unsigned long data) ncm->timer_force_tx = false; } -} - -/* - * The transmit should only be run if no skb data has been sent - * for a certain duration. - */ -static enum hrtimer_restart ncm_tx_timeout(struct hrtimer *data) -{ - struct f_ncm *ncm = container_of(data, struct f_ncm, task_timer); - tasklet_schedule(&ncm->tx_tasklet); return HRTIMER_NORESTART; } @@ -1513,8 +1499,7 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f) ncm->port.open = ncm_open; ncm->port.close = ncm_close; - tasklet_init(&ncm->tx_tasklet, ncm_tx_tasklet, (unsigned long) ncm); - hrtimer_init(&ncm->task_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init(&ncm->task_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT); ncm->task_timer.function = ncm_tx_timeout; DBG(cdev, "CDC Network: %s speed IN/%s OUT/%s NOTIFY/%s\n", @@ -1623,7 +1608,6 @@ static void ncm_unbind(struct usb_configuration *c, struct usb_function *f) DBG(c->cdev, "ncm unbind\n"); hrtimer_cancel(&ncm->task_timer); - tasklet_kill(&ncm->tx_tasklet); ncm_string_defs[0].id = 0; usb_free_all_descriptors(f); -- 2.45.2