ISDN: use irqsave() in URB completion + usb_fill_int_urb

ISDN: use irqsave() in URB completion + usb_fill_int_urb

[Sebastian Andrzej Siewior]

This series is mostly about using _irqsave() primitives in the
completion callback in order to get rid of local_irq_save() in
__usb_hcd_giveback_urb(). While at it, I also tried to move drivers to
use usb_fill_int_urb() otherwise it is hard find users of a certain API.

Sebastian

[PATCH 1/4] isdn: gigaset: use usb_fill_int_urb()

[Sebastian Andrzej Siewior]

Using usb_fill_int_urb() helps to find code which initializes an
URB. A grep for members of the struct (like ->complete) reveal lots
of other things, too.

Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: gigaset307x-common@lists.sourceforge.net
Cc: netdev@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 drivers/isdn/gigaset/bas-gigaset.c | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/drivers/isdn/gigaset/bas-gigaset.c b/drivers/isdn/gigaset/bas-gigaset.c
index 20d0a080a2b0..40c141163f0f 100644
--- a/drivers/isdn/gigaset/bas-gigaset.c
+++ b/drivers/isdn/gigaset/bas-gigaset.c
@@ -972,16 +972,14 @@ static int starturbs(struct bc_state *bcs)
 			rc = -EFAULT;
 			goto error;
 		}
+		usb_fill_int_urb(urb, bcs->cs->hw.bas->udev,
+				 usb_rcvisocpipe(urb->dev, 3 + 2 * bcs->channel),
+				 ubc->isoinbuf + k * BAS_INBUFSIZE,
+				 BAS_INBUFSIZE, read_iso_callback, bcs,
+				 BAS_FRAMETIME);
 
-		urb->dev = bcs->cs->hw.bas->udev;
-		urb->pipe = usb_rcvisocpipe(urb->dev, 3 + 2 * bcs->channel);
 		urb->transfer_flags = URB_ISO_ASAP;
-		urb->transfer_buffer = ubc->isoinbuf + k * BAS_INBUFSIZE;
-		urb->transfer_buffer_length = BAS_INBUFSIZE;
 		urb->number_of_packets = BAS_NUMFRAMES;
-		urb->interval = BAS_FRAMETIME;
-		urb->complete = read_iso_callback;
-		urb->context = bcs;
 		for (j = 0; j < BAS_NUMFRAMES; j++) {
 			urb->iso_frame_desc[j].offset = j * BAS_MAXFRAME;
 			urb->iso_frame_desc[j].length = BAS_MAXFRAME;
@@ -1005,15 +1003,15 @@ static int starturbs(struct bc_state *bcs)
 			rc = -EFAULT;
 			goto error;
 		}
-		urb->dev = bcs->cs->hw.bas->udev;
-		urb->pipe = usb_sndisocpipe(urb->dev, 4 + 2 * bcs->channel);
+		usb_fill_int_urb(urb, bcs->cs->hw.bas->udev,
+				 usb_sndisocpipe(urb->dev, 4 + 2 * bcs->channel),
+				 ubc->isooutbuf->data,
+				 sizeof(ubc->isooutbuf->data),
+				 write_iso_callback, &ubc->isoouturbs[k],
+				 BAS_FRAMETIME);
+
 		urb->transfer_flags = URB_ISO_ASAP;
-		urb->transfer_buffer = ubc->isooutbuf->data;
-		urb->transfer_buffer_length = sizeof(ubc->isooutbuf->data);
 		urb->number_of_packets = BAS_NUMFRAMES;
-		urb->interval = BAS_FRAMETIME;
-		urb->complete = write_iso_callback;
-		urb->context = &ubc->isoouturbs[k];
 		for (j = 0; j < BAS_NUMFRAMES; ++j) {
 			urb->iso_frame_desc[j].offset = BAS_OUTBUFSIZE;
 			urb->iso_frame_desc[j].length = BAS_NORMFRAME;
-- 
2.17.1

[PATCH 2/4] isdn: hisax: hfc_usb: use usb_fill_int_urb()

[Sebastian Andrzej Siewior]

Using usb_fill_int_urb() helps to find code which initializes an
URB. A grep for members of the struct (like ->complete) reveal lots
of other things, too.

The `interval' parameter is now set differently on HS and SS. The
argument is fed from bInterval so it should be the right thing to do.

Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: netdev@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 drivers/isdn/hisax/hfc_usb.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/isdn/hisax/hfc_usb.c b/drivers/isdn/hisax/hfc_usb.c
index 97ecb3073045..1d4cd01d4685 100644
--- a/drivers/isdn/hisax/hfc_usb.c
+++ b/drivers/isdn/hisax/hfc_usb.c
@@ -432,16 +432,12 @@ fill_isoc_urb(struct urb *urb, struct usb_device *dev, unsigned int pipe,
 {
 	int k;
 
-	urb->dev = dev;
-	urb->pipe = pipe;
-	urb->complete = complete;
+	usb_fill_int_urb(urb, dev, pipe, buf, packet_size * num_packets,
+			 complete, context, interval);
+
 	urb->number_of_packets = num_packets;
-	urb->transfer_buffer_length = packet_size * num_packets;
-	urb->context = context;
-	urb->transfer_buffer = buf;
 	urb->transfer_flags = URB_ISO_ASAP;
 	urb->actual_length = 0;
-	urb->interval = interval;
 	for (k = 0; k < num_packets; k++) {
 		urb->iso_frame_desc[k].offset = packet_size * k;
 		urb->iso_frame_desc[k].length = packet_size;
-- 
2.17.1

[PATCH 3/4] isdn: hisax: st5481_usb: use usb_fill_int_urb()

[Sebastian Andrzej Siewior]

Using usb_fill_int_urb() helps to find code which initializes an
URB. A grep for members of the struct (like ->complete) reveal lots
of other things, too.

Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: netdev@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 drivers/isdn/hisax/st5481_usb.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/isdn/hisax/st5481_usb.c b/drivers/isdn/hisax/st5481_usb.c
index 1cb9930d5e24..f207fda691c7 100644
--- a/drivers/isdn/hisax/st5481_usb.c
+++ b/drivers/isdn/hisax/st5481_usb.c
@@ -408,15 +408,10 @@ fill_isoc_urb(struct urb *urb, struct usb_device *dev,
 {
 	int k;
 
-	urb->dev = dev;
-	urb->pipe = pipe;
-	urb->interval = 1;
-	urb->transfer_buffer = buf;
+	usb_fill_int_urb(urb, dev, pipe, buf, num_packets * packet_size,
+			 complete, context, 1);
+
 	urb->number_of_packets = num_packets;
-	urb->transfer_buffer_length = num_packets * packet_size;
-	urb->actual_length = 0;
-	urb->complete = complete;
-	urb->context = context;
 	urb->transfer_flags = URB_ISO_ASAP;
 	for (k = 0; k < num_packets; k++) {
 		urb->iso_frame_desc[k].offset = packet_size * k;
-- 
2.17.1

[PATCH 4/4] isdn: mISDN: use irqsave() in USB's complete callback

[Sebastian Andrzej Siewior]

The USB completion callback does not disable interrupts while acquiring
the ->lock. We want to remove the local_irq_disable() invocation from
__usb_hcd_giveback_urb() and therefore it is required for the callback
handler to disable the interrupts while acquiring the lock.
The callback may be invoked either in IRQ or BH context depending on the
USB host controller.
Use the _irqsave() variant of the locking primitives.

Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: netdev@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 drivers/isdn/hardware/mISDN/hfcsusb.c | 36 +++++++++++++++------------
 1 file changed, 20 insertions(+), 16 deletions(-)

diff --git a/drivers/isdn/hardware/mISDN/hfcsusb.c b/drivers/isdn/hardware/mISDN/hfcsusb.c
index 17cc879ad2bb..6d05946b445e 100644
--- a/drivers/isdn/hardware/mISDN/hfcsusb.c
+++ b/drivers/isdn/hardware/mISDN/hfcsusb.c
@@ -819,6 +819,7 @@ hfcsusb_rx_frame(struct usb_fifo *fifo, __u8 *data, unsigned int len,
 	int		fifon = fifo->fifonum;
 	int		i;
 	int		hdlc = 0;
+	unsigned long	flags;
 
 	if (debug & DBG_HFC_CALL_TRACE)
 		printk(KERN_DEBUG "%s: %s: fifo(%i) len(%i) "
@@ -835,7 +836,7 @@ hfcsusb_rx_frame(struct usb_fifo *fifo, __u8 *data, unsigned int len,
 		return;
 	}
 
-	spin_lock(&hw->lock);
+	spin_lock_irqsave(&hw->lock, flags);
 	if (fifo->dch) {
 		rx_skb = fifo->dch->rx_skb;
 		maxlen = fifo->dch->maxlen;
@@ -844,7 +845,7 @@ hfcsusb_rx_frame(struct usb_fifo *fifo, __u8 *data, unsigned int len,
 	if (fifo->bch) {
 		if (test_bit(FLG_RX_OFF, &fifo->bch->Flags)) {
 			fifo->bch->dropcnt += len;
-			spin_unlock(&hw->lock);
+			spin_unlock_irqrestore(&hw->lock, flags);
 			return;
 		}
 		maxlen = bchannel_get_rxbuf(fifo->bch, len);
@@ -854,7 +855,7 @@ hfcsusb_rx_frame(struct usb_fifo *fifo, __u8 *data, unsigned int len,
 				skb_trim(rx_skb, 0);
 			pr_warning("%s.B%d: No bufferspace for %d bytes\n",
 				   hw->name, fifo->bch->nr, len);
-			spin_unlock(&hw->lock);
+			spin_unlock_irqrestore(&hw->lock, flags);
 			return;
 		}
 		maxlen = fifo->bch->maxlen;
@@ -878,7 +879,7 @@ hfcsusb_rx_frame(struct usb_fifo *fifo, __u8 *data, unsigned int len,
 			} else {
 				printk(KERN_DEBUG "%s: %s: No mem for rx_skb\n",
 				       hw->name, __func__);
-				spin_unlock(&hw->lock);
+				spin_unlock_irqrestore(&hw->lock, flags);
 				return;
 			}
 		}
@@ -888,7 +889,7 @@ hfcsusb_rx_frame(struct usb_fifo *fifo, __u8 *data, unsigned int len,
 			       "for fifo(%d) HFCUSB_D_RX\n",
 			       hw->name, __func__, fifon);
 			skb_trim(rx_skb, 0);
-			spin_unlock(&hw->lock);
+			spin_unlock_irqrestore(&hw->lock, flags);
 			return;
 		}
 	}
@@ -942,7 +943,7 @@ hfcsusb_rx_frame(struct usb_fifo *fifo, __u8 *data, unsigned int len,
 		/* deliver transparent data to layer2 */
 		recv_Bchannel(fifo->bch, MISDN_ID_ANY, false);
 	}
-	spin_unlock(&hw->lock);
+	spin_unlock_irqrestore(&hw->lock, flags);
 }
 
 static void
@@ -979,18 +980,19 @@ rx_iso_complete(struct urb *urb)
 	__u8 *buf;
 	static __u8 eof[8];
 	__u8 s0_state;
+	unsigned long flags;
 
 	fifon = fifo->fifonum;
 	status = urb->status;
 
-	spin_lock(&hw->lock);
+	spin_lock_irqsave(&hw->lock, flags);
 	if (fifo->stop_gracefull) {
 		fifo->stop_gracefull = 0;
 		fifo->active = 0;
-		spin_unlock(&hw->lock);
+		spin_unlock_irqrestore(&hw->lock, flags);
 		return;
 	}
-	spin_unlock(&hw->lock);
+	spin_unlock_irqrestore(&hw->lock, flags);
 
 	/*
 	 * ISO transfer only partially completed,
@@ -1096,15 +1098,16 @@ rx_int_complete(struct urb *urb)
 	struct usb_fifo *fifo = (struct usb_fifo *) urb->context;
 	struct hfcsusb *hw = fifo->hw;
 	static __u8 eof[8];
+	unsigned long flags;
 
-	spin_lock(&hw->lock);
+	spin_lock_irqsave(&hw->lock, flags);
 	if (fifo->stop_gracefull) {
 		fifo->stop_gracefull = 0;
 		fifo->active = 0;
-		spin_unlock(&hw->lock);
+		spin_unlock_irqrestore(&hw->lock, flags);
 		return;
 	}
-	spin_unlock(&hw->lock);
+	spin_unlock_irqrestore(&hw->lock, flags);
 
 	fifon = fifo->fifonum;
 	if ((!fifo->active) || (urb->status)) {
@@ -1172,12 +1175,13 @@ tx_iso_complete(struct urb *urb)
 	int *tx_idx;
 	int frame_complete, fifon, status, fillempty = 0;
 	__u8 threshbit, *p;
+	unsigned long flags;
 
-	spin_lock(&hw->lock);
+	spin_lock_irqsave(&hw->lock, flags);
 	if (fifo->stop_gracefull) {
 		fifo->stop_gracefull = 0;
 		fifo->active = 0;
-		spin_unlock(&hw->lock);
+		spin_unlock_irqrestore(&hw->lock, flags);
 		return;
 	}
 
@@ -1195,7 +1199,7 @@ tx_iso_complete(struct urb *urb)
 	} else {
 		printk(KERN_DEBUG "%s: %s: neither BCH nor DCH\n",
 		       hw->name, __func__);
-		spin_unlock(&hw->lock);
+		spin_unlock_irqrestore(&hw->lock, flags);
 		return;
 	}
 
@@ -1375,7 +1379,7 @@ tx_iso_complete(struct urb *urb)
 			       hw->name, __func__,
 			       symbolic(urb_errlist, status), status, fifon);
 	}
-	spin_unlock(&hw->lock);
+	spin_unlock_irqrestore(&hw->lock, flags);
 }
 
 /*
-- 
2.17.1

Re: ISDN: use irqsave() in URB completion + usb_fill_int_urb

[David Miller]

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 20 Jun 2018 12:40:24 +0200

> This series is mostly about using _irqsave() primitives in the
> completion callback in order to get rid of local_irq_save() in
> __usb_hcd_giveback_urb(). While at it, I also tried to move drivers to
> use usb_fill_int_urb() otherwise it is hard find users of a certain API.

Series applied, thanks Sebastian.