Re: [PATCH v2 0/1] Input: xpad - Implement wireless controller LED setting and fix connect time LED setting

On Mon, 10 Dec 2012 04:43:54 -0800
Chris Moeller [off-list ref] wrote:

quoted

On Mon, 10 Dec 2012 02:58:25 -0800
Chris Moeller [off-list ref] wrote:

quoted

On Sun, 2 Dec 2012 23:43:18 -0800
Dmitry Torokhov [off-list ref] wrote:

quoted

On Fri, Nov 30, 2012 at 08:13:29PM -0800, Chris Moeller wrote:

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On Fri, 30 Nov 2012 14:30:23 -0800
Dmitry Torokhov [off-list ref] wrote:

quoted

Hi Chris,

On Friday, November 30, 2012 01:54:06 PM Chris Moeller
wrote:

quoted

I've submitted versions of this with prior patch sets, and
this part was never accepted, possibly because it depended
on other patches to work, or possibly because it wasn't so
cleanly organized. This time, I've split the LED setting
command off into its own static function, then call that
on controller connect and optionally on LED setting
commands. The static function does not include any
locking, because locking inside the function which
receives the incoming packets deadlocks the driver, and
does not appear to be necessary anyway.

It also removes all traces of the original bulk out
function which was designed for the purpose of setting
the LED status on connect, as I found that it actually
does not work at all. It appears to try to send the data,
but nothing actually happens to the controller LEDs.

Attached is a reply I sent to on 7/4/11 to which you
unfortunately never responded. The issue is that of force
feedback (rumble) and LED share the same URB then access to
that URB should be arbitrated. The attached message
contains a patch that attempts to implement that
arbitration, could you please try it out and see what
changes are needed to make it work?

Thanks.

So sorry I missed your reply. That's what I get for filtering
the mailing list messages past my inbox, then never following
up on my filter/folder set for replies to my own messages. I
recall you mentioned that potential race condition when I
first submitted, but I forgot to do anything about it. I'm
glad at least one of us has our stuff together. It seems to
work just fine, but there may be a force feedback issue with
the following test program, where it leaves the effect playing
indefinitely after the program terminates, and then the
controller itself ceases to respond until the module is
removed and reloaded.

Just to confirm, you see this problem only with the patch being
discussed and do not see it without it, right?

Yeah, the problem only happens with this patch. Here's a silly
mess which fixes it. If you can think of a better way to handle
pending commands outside of the IRQ, be my guest. The problem
seems to be that it doesn't like sending further commands from
inside the output irq callback, so further commands are not sent,
and the spinlock is left locked or something. So it seems that it
needs to be such that the callback merely signals when the packet
has completed sending, and the actual queue must be handled
outside of the irq, and somehow kindly wait for the irq to
complete for each command. Unless, you know, there's some other
way to queue up multiple commands without waiting on each one to
complete. I know bulk out doesn't work for the LED setting
command, at least. Anyway, here goes.

Disregard this patch, it locks up frequently. I'm working on
something else instead.

Okay, this one seems to work. LED setting doesn't lock up like the old
mutex regulated LED setting mode, and I can successfully power off and
on the controller while that previously posted test program is still
running on the event device, without the LED setting clobbering the
rumble packets, and vice versa.

---
diff -urpN a/drivers/input/joystick/xpad.c
b/drivers/input/joystick/xpad.c ---
a/drivers/input/joystick/xpad.c	2012-12-10 03:59:14.407669714
-0800 +++ b/drivers/input/joystick/xpad.c	2012-12-10
05:13:22.835479280 -0800 @@ -259,19 +259,17 @@ struct usb_xpad
{ struct usb_interface *intf;	/* usb interface */ 
 	int pad_present;
+	int interface_number;
 
 	struct urb *irq_in;		/* urb for interrupt in
report */ unsigned char *idata;		/* input data */
 	dma_addr_t idata_dma;
 
-	struct urb *bulk_out;
-	unsigned char *bdata;
-
 #if defined(CONFIG_JOYSTICK_XPAD_FF) ||
defined(CONFIG_JOYSTICK_XPAD_LEDS) struct urb
*irq_out;		/* urb for interrupt out report */ unsigned
char *odata;		/* output data */ dma_addr_t odata_dma;
-	struct mutex odata_mutex;
+	spinlock_t odata_lock;
 #endif
 
 #if defined(CONFIG_JOYSTICK_XPAD_LEDS)

@@ -441,13 +439,15 @@ static void xpad360_process_packet(struc
  *
  */
 
+static void xpad_send_led_command(struct usb_xpad *xpad, int

command); +
 static void xpad360w_process_packet(struct usb_xpad *xpad, u16 cmd,
unsigned char *data) {
 	/* Presence change */
 	if (data[0] & 0x08) {
 		if (data[1] & 0x80) {
 			xpad->pad_present = 1;
-			usb_submit_urb(xpad->bulk_out, GFP_ATOMIC);
+			xpad_send_led_command(xpad, 16);
 		} else
 			xpad->pad_present = 0;
 	}

@@ -502,29 +502,6 @@ exit:
 			__func__, retval);
 }
 
-static void xpad_bulk_out(struct urb *urb)
-{
-	struct usb_xpad *xpad = urb->context;
-	struct device *dev = &xpad->intf->dev;
-
-	switch (urb->status) {
-	case 0:
-		/* success */
-		break;
-	case -ECONNRESET:
-	case -ENOENT:
-	case -ESHUTDOWN:
-		/* this urb is terminated, clean up */
-		dev_dbg(dev, "%s - urb shutting down with status:

%d\n",
-			__func__, urb->status);
-		break;
-	default:
-		dev_dbg(dev, "%s - nonzero urb status received:
%d\n",
-			__func__, urb->status);
-	}
-}
-
-#if defined(CONFIG_JOYSTICK_XPAD_FF) ||
defined(CONFIG_JOYSTICK_XPAD_LEDS) static void xpad_irq_out(struct
urb *urb) {
 	struct usb_xpad *xpad = urb->context;

@@ -574,7 +551,7 @@ static int xpad_init_output(struct usb_i
 		goto fail1;
 	}
 
-	mutex_init(&xpad->odata_mutex);
+	spin_lock_init(&xpad->odata_lock);
 
 	xpad->irq_out = usb_alloc_urb(0, GFP_KERNEL);
 	if (!xpad->irq_out) {

@@ -610,15 +587,12 @@ static void xpad_deinit_output(struct us
 				xpad->odata, xpad->odata_dma);
 	}
 }
-#else
-static int xpad_init_output(struct usb_interface *intf, struct

usb_xpad *xpad) { return 0; } -static void xpad_deinit_output(struct
usb_xpad *xpad) {} -static void xpad_stop_output(struct usb_xpad
*xpad) {} -#endif
 
 #ifdef CONFIG_JOYSTICK_XPAD_FF
 static int xpad_play_effect(struct input_dev *dev, void *data,
struct ff_effect *effect) {
+	int retval;
+	unsigned long flags;
 	struct usb_xpad *xpad = input_get_drvdata(dev);
 
 	if (effect->type == FF_RUMBLE) {

@@ -628,6 +602,7 @@ static int xpad_play_effect(struct input
 		switch (xpad->xtype) {
 
 		case XTYPE_XBOX:
+			spin_lock_irqsave(&xpad->odata_lock, flags);
 			xpad->odata[0] = 0x00;
 			xpad->odata[1] = 0x06;
 			xpad->odata[2] = 0x00;

@@ -636,9 +611,13 @@ static int xpad_play_effect(struct input
 			xpad->odata[5] = weak / 256;	/* right

actuator */ xpad->irq_out->transfer_buffer_length = 6;
 
-			return usb_submit_urb(xpad->irq_out,
GFP_ATOMIC);
+			retval = usb_submit_urb(xpad->irq_out,
GFP_ATOMIC);
+			spin_unlock_irqrestore(&xpad->odata_lock,
flags); +
+			return retval;
 
 		case XTYPE_XBOX360:
+			spin_lock_irqsave(&xpad->odata_lock, flags);
 			xpad->odata[0] = 0x00;
 			xpad->odata[1] = 0x08;
 			xpad->odata[2] = 0x00;

@@ -649,9 +628,13 @@ static int xpad_play_effect(struct input
 			xpad->odata[7] = 0x00;
 			xpad->irq_out->transfer_buffer_length = 8;
 
-			return usb_submit_urb(xpad->irq_out,

GFP_ATOMIC);
+			retval = usb_submit_urb(xpad->irq_out,
GFP_ATOMIC);
+			spin_unlock_irqrestore(&xpad->odata_lock,
flags); +
+			return retval;
 
 		case XTYPE_XBOX360W:
+			spin_lock_irqsave(&xpad->odata_lock, flags);
 			xpad->odata[0] = 0x00;
 			xpad->odata[1] = 0x01;
 			xpad->odata[2] = 0x0F;

@@ -666,7 +649,10 @@ static int xpad_play_effect(struct input
 			xpad->odata[11] = 0x00;
 			xpad->irq_out->transfer_buffer_length = 12;
 
-			return usb_submit_urb(xpad->irq_out,

GFP_ATOMIC);
+			retval = usb_submit_urb(xpad->irq_out,
GFP_ATOMIC);
+			spin_unlock_irqrestore(&xpad->odata_lock,
flags); +
+			return retval;
 
 		default:
 			dev_dbg(&xpad->dev->dev,

@@ -693,6 +679,43 @@ static int xpad_init_ff(struct usb_xpad
 static int xpad_init_ff(struct usb_xpad *xpad) { return 0; }
 #endif
 
+static void xpad_send_led_command(struct usb_xpad *xpad, int command)
+{
+	unsigned long flags;
+	if (xpad->xtype == XTYPE_XBOX360) {
+		if (command >= 0 && command < 14) {
+			spin_lock_irqsave(&xpad->odata_lock, flags);
+			xpad->odata[0] = 0x01;
+			xpad->odata[1] = 0x03;
+			xpad->odata[2] = command;
+			xpad->irq_out->transfer_buffer_length = 3;
+			usb_submit_urb(xpad->irq_out, GFP_KERNEL);
+			spin_unlock_irqrestore(&xpad->odata_lock,

flags);
+		}
+	} else if (xpad->xtype == XTYPE_XBOX360W) {
+		if (command >= 0 && command < 17) {
+			if (command == 16)
+				command = 0x02 +
xpad->interface_number;
+			spin_lock_irqsave(&xpad->odata_lock, flags);
+			xpad->odata[0] = 0x00;
+			xpad->odata[1] = 0x00;
+			xpad->odata[2] = 0x08;
+			xpad->odata[3] = 0x40 + command;
+			xpad->odata[4] = 0x00;
+			xpad->odata[5] = 0x00;
+			xpad->odata[6] = 0x00;
+			xpad->odata[7] = 0x00;
+			xpad->odata[8] = 0x00;
+			xpad->odata[9] = 0x00;
+			xpad->odata[10] = 0x00;
+			xpad->odata[11] = 0x00;
+			xpad->irq_out->transfer_buffer_length = 12;
+			usb_submit_urb(xpad->irq_out, GFP_KERNEL);
+			spin_unlock_irqrestore(&xpad->odata_lock,
flags);
+		}
+	}
+}
+
 #if defined(CONFIG_JOYSTICK_XPAD_LEDS)
 #include <linux/leds.h>
 

@@ -702,19 +725,6 @@ struct xpad_led {
 	struct usb_xpad *xpad;
 };
 
-static void xpad_send_led_command(struct usb_xpad *xpad, int command)
-{
-	if (command >= 0 && command < 14) {
-		mutex_lock(&xpad->odata_mutex);
-		xpad->odata[0] = 0x01;
-		xpad->odata[1] = 0x03;
-		xpad->odata[2] = command;
-		xpad->irq_out->transfer_buffer_length = 3;
-		usb_submit_urb(xpad->irq_out, GFP_KERNEL);
-		mutex_unlock(&xpad->odata_mutex);
-	}
-}
-
 static void xpad_led_set(struct led_classdev *led_cdev,
 			 enum led_brightness value)
 {

@@ -732,7 +742,7 @@ static int xpad_led_probe(struct usb_xpa
 	struct led_classdev *led_cdev;
 	int error;
 
-	if (xpad->xtype != XTYPE_XBOX360)
+	if (xpad->xtype != XTYPE_XBOX360 && xpad->xtype !=

XTYPE_XBOX360W) return 0;
 
 	xpad->led = led = kzalloc(sizeof(struct xpad_led),
GFP_KERNEL); @@ -758,7 +768,8 @@ static int xpad_led_probe(struct
usb_xpa /*
 	 * Light up the segment corresponding to controller number
 	 */
-	xpad_send_led_command(xpad, (led_no % 4) + 2);
+	if (xpad->xtype == XTYPE_XBOX360)
+		xpad_send_led_command(xpad, (led_no % 4) + 2);
 
 	return 0;
 }

@@ -960,42 +971,7 @@ static int xpad_probe(struct usb_interfa
 	usb_set_intfdata(intf, xpad);
 
 	if (xpad->xtype == XTYPE_XBOX360W) {
-		/*
-		 * Setup the message to set the LEDs on the
-		 * controller when it shows up
-		 */
-		xpad->bulk_out = usb_alloc_urb(0, GFP_KERNEL);
-		if (!xpad->bulk_out) {
-			error = -ENOMEM;
-			goto fail7;
-		}
-
-		xpad->bdata = kzalloc(XPAD_PKT_LEN, GFP_KERNEL);
-		if (!xpad->bdata) {
-			error = -ENOMEM;
-			goto fail8;
-		}
-
-		xpad->bdata[2] = 0x08;
-		switch (intf->cur_altsetting->desc.bInterfaceNumber)

{
-		case 0:
-			xpad->bdata[3] = 0x42;
-			break;
-		case 2:
-			xpad->bdata[3] = 0x43;
-			break;
-		case 4:
-			xpad->bdata[3] = 0x44;
-			break;
-		case 6:
-			xpad->bdata[3] = 0x45;
-		}
-
-		ep_irq_in = &intf->cur_altsetting->endpoint[1].desc;
-		usb_fill_bulk_urb(xpad->bulk_out, udev,
-				usb_sndbulkpipe(udev,
ep_irq_in->bEndpointAddress),
-				xpad->bdata, XPAD_PKT_LEN,
xpad_bulk_out, xpad); -
+		xpad->interface_number =
intf->cur_altsetting->desc.bInterfaceNumber / 2; /*
 		 * Submit the int URB immediately rather than
waiting for open
 		 * because we get status messages from the device
whether @@ -1006,13 +982,11 @@ static int xpad_probe(struct
usb_interfa xpad->irq_in->dev = xpad->udev;
 		error = usb_submit_urb(xpad->irq_in, GFP_KERNEL);
 		if (error)
-			goto fail9;
+			goto fail7;
 	}
 
 	return 0;
 
- fail9:	kfree(xpad->bdata);
- fail8:	usb_free_urb(xpad->bulk_out);
  fail7:	input_unregister_device(input_dev);
 	input_dev = NULL;
  fail6:	xpad_led_disconnect(xpad);

@@ -1036,8 +1010,6 @@ static void xpad_disconnect(struct usb_i
 	xpad_deinit_output(xpad);
 
 	if (xpad->xtype == XTYPE_XBOX360W) {
-		usb_kill_urb(xpad->bulk_out);
-		usb_free_urb(xpad->bulk_out);
 		usb_kill_urb(xpad->irq_in);
 	}
 

@@ -1045,9 +1017,6 @@ static void xpad_disconnect(struct usb_i
 	usb_free_coherent(xpad->udev, XPAD_PKT_LEN,
 			xpad->idata, xpad->idata_dma);
 
-	kfree(xpad->bdata);
-	kfree(xpad);
-
 	usb_set_intfdata(intf, NULL);
 }