Re: [PATCH 10/15] Input: xpad: use ida() for finding the pad_nr

From: Pavel Rojtberg <rojtberg@gmail.com>
To: linux-input@vger.kernel.org, pgriffais@valvesoftware.com,
	dmitry.torokhov@gmail.com, gregkh@linuxfoundation.org
Subject: Re: [PATCH 10/15] Input: xpad: use ida() for finding the pad_nr
Date: Fri, 2 Oct 2015 00:53:26 +0200	[thread overview]
Message-ID: <560DB966.8080602@gmail.com> (raw)
In-Reply-To: <1443733046-29610-11-git-send-email-rojtberg@gmail.com>

sorry, I messed up this one. This would be the correct patch.
Should I re-spin the whole series or would it be too much noise?

Subject: [PATCH 10/15] Input: xpad: use ida() for finding the pad_nr

The pad_nr corresponds to the lit up LED on the controller. Therefore
there should be no gaps when enumerating. Currently a LED is only
re-assigned after a controller is re-connected 4 times.

This patch uses ida to track connected pads - this way we can re-assign
freed up pad number immediately.

Consider the following case:
1. pad A is connected and gets pad_nr = 0
2. pad B is connected and gets pad_nr = 1
3. pad A is disconnected
4. pad A is connected again

using ida_simple_get() controller A now correctly gets pad_nr = 0 again.

Signed-off-by: Pavel Rojtberg <rojtberg@gmail.com>
---
  drivers/input/joystick/xpad.c | 30 +++++++++++++++++++++++-------
  1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/drivers/input/joystick/xpad.c b/drivers/input/joystick/xpad.c
index 31bcd78..b83ea3c 100644
--- a/drivers/input/joystick/xpad.c
+++ b/drivers/input/joystick/xpad.c
@@ -342,11 +342,13 @@ struct usb_xpad {

      int mapping;            /* map d-pad to buttons or to axes */
      int xtype;            /* type of xbox device */
-    unsigned long pad_nr;        /* the order x360 pads were attached */
+    int pad_nr;            /* the order x360 pads were attached */
      const char *name;        /* name of the device */
      struct work_struct work;    /* init/remove device from callback */
  };

+static DEFINE_IDA(xpad_pad_seq);
+
  static int xpad_init_input(struct usb_xpad *xpad);
  static void xpad_deinit_input(struct usb_xpad *xpad);

@@ -946,6 +948,16 @@ static void xpad_send_led_command(struct usb_xpad 
*xpad, int command)
   */
  static void xpad_identify_controller(struct usb_xpad *xpad)
  {
+    if (xpad->xtype != XTYPE_XBOX360 && xpad->xtype != XTYPE_XBOX360W)
+        return;
+
+    xpad->pad_nr = ida_simple_get(&xpad_pad_seq, 0, 0, GFP_KERNEL);
+
+    if(xpad->pad_nr < 0) {
+        dev_dbg(&xpad->dev->dev, "%s - ida_get failed\n", __func__);
+        return;
+    }
+
      xpad_send_led_command(xpad, (xpad->pad_nr % 4) + 2);
  }

@@ -960,7 +972,6 @@ static void xpad_led_set(struct led_classdev *led_cdev,

  static int xpad_led_probe(struct usb_xpad *xpad)
  {
-    static atomic_t led_seq = ATOMIC_INIT(-1);
      struct xpad_led *led;
      struct led_classdev *led_cdev;
      int error;
@@ -972,9 +983,7 @@ static int xpad_led_probe(struct usb_xpad *xpad)
      if (!led)
          return -ENOMEM;

-    xpad->pad_nr = atomic_inc_return(&led_seq);
-
-    snprintf(led->name, sizeof(led->name), "xpad%lu", xpad->pad_nr);
+    snprintf(led->name, sizeof(led->name), "xpad%d", xpad->pad_nr);
      led->xpad = xpad;

      led_cdev = &led->led_cdev;
@@ -1132,6 +1141,8 @@ static int xpad_init_input(struct usb_xpad *xpad)
              xpad_set_up_abs(input_dev, xpad_abs_triggers[i]);
      }

+    xpad_identify_controller(xpad);
+
      error = xpad_init_ff(xpad);
      if (error)
          goto fail_init_ff;
@@ -1144,8 +1155,6 @@ static int xpad_init_input(struct usb_xpad *xpad)
      if (error)
          goto fail_input_register;

-    xpad_identify_controller(xpad);
-
      return 0;

  fail_input_register:
@@ -1305,6 +1314,13 @@ static void xpad_deinit_input(struct usb_xpad *xpad)
  {
      xpad_led_disconnect(xpad);
      input_unregister_device(xpad->dev);
+
+    if (xpad->xtype != XTYPE_XBOX360 && xpad->xtype != XTYPE_XBOX360W)
+        return;
+
+    if(xpad->pad_nr > -1) {
+        ida_simple_remove(&xpad_pad_seq, xpad->pad_nr);
+    }
  }

  static void xpad_disconnect(struct usb_interface *intf)
-- 
1.9.1

