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* [PATCH 1/1] HID: Fix missing Unifying device issue
@ 2012-09-21 10:21 Nestor Lopez Casado
  2012-09-22  7:50 ` Jiri Kosina
  2012-09-23 10:23 ` Josip Rodin
  0 siblings, 2 replies; 7+ messages in thread
From: Nestor Lopez Casado @ 2012-09-21 10:21 UTC (permalink / raw)
  To: Jiri Kosina
  Cc: Benjamin Tissoires, linux-input, linux-kernel, 685360,
	john.ettedgui, barz621, joy, dh.herrmann, Nestor Lopez Casado

This patch fixes an issue introduced after commit 4ea5454203d991ec

After that commit, hid-core silently discards any incoming packet
that arrives while any hid driver's probe function is being executed.

This broke the enumeration process of hid-logitech-dj, that must
receive control packets in-band with the mouse and keyboard
packets. Discarding mouse or keyboard data at the very begining is
usually fine, but it is not the case for control packets.

This patch forces a re-enumeration of the paired devices when a packet
arrives that comes from an unknown device.

Based on a patch originally written by Benjamin Tissoires.

Signed-off-by: Nestor Lopez Casado <nlopezcasad@logitech.com>
---

Hello Jiri, David,

      I suggest we include this patch as this solves the issue with the 
      Unifying devices while we decide the future of the lock in hid-core.

      Cheers,
      Nestor

 drivers/hid/hid-logitech-dj.c |   45 +++++++++++++++++++++++++++++++++++++++++
 drivers/hid/hid-logitech-dj.h |    1 +
 2 files changed, 46 insertions(+), 0 deletions(-)

diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c
index 4d524b5..9500f2f 100644
--- a/drivers/hid/hid-logitech-dj.c
+++ b/drivers/hid/hid-logitech-dj.c
@@ -193,6 +193,7 @@ static struct hid_ll_driver logi_dj_ll_driver;
 static int logi_dj_output_hidraw_report(struct hid_device *hid, u8 * buf,
 					size_t count,
 					unsigned char report_type);
+static int logi_dj_recv_query_paired_devices(struct dj_receiver_dev *djrcv_dev);
 
 static void logi_dj_recv_destroy_djhid_device(struct dj_receiver_dev *djrcv_dev,
 						struct dj_report *dj_report)
@@ -233,6 +234,7 @@ static void logi_dj_recv_add_djhid_device(struct dj_receiver_dev *djrcv_dev,
 	if (dj_report->report_params[DEVICE_PAIRED_PARAM_SPFUNCTION] &
 	    SPFUNCTION_DEVICE_LIST_EMPTY) {
 		dbg_hid("%s: device list is empty\n", __func__);
+		djrcv_dev->querying_devices = false;
 		return;
 	}
 
@@ -243,6 +245,12 @@ static void logi_dj_recv_add_djhid_device(struct dj_receiver_dev *djrcv_dev,
 		return;
 	}
 
+	if (djrcv_dev->paired_dj_devices[dj_report->device_index]) {
+		/* The device is already known. No need to reallocate it. */
+		dbg_hid("%s: device is already known\n", __func__);
+		return;
+	}
+
 	dj_hiddev = hid_allocate_device();
 	if (IS_ERR(dj_hiddev)) {
 		dev_err(&djrcv_hdev->dev, "%s: hid_allocate_device failed\n",
@@ -306,6 +314,7 @@ static void delayedwork_callback(struct work_struct *work)
 	struct dj_report dj_report;
 	unsigned long flags;
 	int count;
+	int retval;
 
 	dbg_hid("%s\n", __func__);
 
@@ -338,6 +347,25 @@ static void delayedwork_callback(struct work_struct *work)
 		logi_dj_recv_destroy_djhid_device(djrcv_dev, &dj_report);
 		break;
 	default:
+	/* A normal report (i. e. not belonging to a pair/unpair notification)
+	 * arriving here, means that the report arrived but we did not have a
+	 * paired dj_device associated to the report's device_index, this
+	 * means that the original "device paired" notification corresponding
+	 * to this dj_device never arrived to this driver. The reason is that
+	 * hid-core discards all packets coming from a device while probe() is
+	 * executing. */
+	if (!djrcv_dev->paired_dj_devices[dj_report.device_index]) {
+		/* ok, we don't know the device, just re-ask the
+		 * receiver for the list of connected devices. */
+		retval = logi_dj_recv_query_paired_devices(djrcv_dev);
+		if (!retval) {
+			/* everything went fine, so just leave */
+			break;
+		}
+		dev_err(&djrcv_dev->hdev->dev,
+			"%s:logi_dj_recv_query_paired_devices "
+			"error:%d\n", __func__, retval);
+		}
 		dbg_hid("%s: unexpected report type\n", __func__);
 	}
 }
@@ -368,6 +396,12 @@ static void logi_dj_recv_forward_null_report(struct dj_receiver_dev *djrcv_dev,
 	if (!djdev) {
 		dbg_hid("djrcv_dev->paired_dj_devices[dj_report->device_index]"
 			" is NULL, index %d\n", dj_report->device_index);
+		kfifo_in(&djrcv_dev->notif_fifo, dj_report, sizeof(struct dj_report));
+
+		if (schedule_work(&djrcv_dev->work) == 0) {
+			dbg_hid("%s: did not schedule the work item, was already "
+			"queued\n", __func__);
+		}
 		return;
 	}
 
@@ -398,6 +432,12 @@ static void logi_dj_recv_forward_report(struct dj_receiver_dev *djrcv_dev,
 	if (dj_device == NULL) {
 		dbg_hid("djrcv_dev->paired_dj_devices[dj_report->device_index]"
 			" is NULL, index %d\n", dj_report->device_index);
+		kfifo_in(&djrcv_dev->notif_fifo, dj_report, sizeof(struct dj_report));
+
+		if (schedule_work(&djrcv_dev->work) == 0) {
+			dbg_hid("%s: did not schedule the work item, was already "
+			"queued\n", __func__);
+		}
 		return;
 	}
 
@@ -439,6 +479,10 @@ static int logi_dj_recv_query_paired_devices(struct dj_receiver_dev *djrcv_dev)
 	struct dj_report *dj_report;
 	int retval;
 
+	/* no need to protect djrcv_dev->querying_devices */
+	if (djrcv_dev->querying_devices)
+		return 0;
+
 	dj_report = kzalloc(sizeof(struct dj_report), GFP_KERNEL);
 	if (!dj_report)
 		return -ENOMEM;
@@ -450,6 +494,7 @@ static int logi_dj_recv_query_paired_devices(struct dj_receiver_dev *djrcv_dev)
 	return retval;
 }
 
+
 static int logi_dj_recv_switch_to_dj_mode(struct dj_receiver_dev *djrcv_dev,
 					  unsigned timeout)
 {
diff --git a/drivers/hid/hid-logitech-dj.h b/drivers/hid/hid-logitech-dj.h
index fd28a5e..4a40003 100644
--- a/drivers/hid/hid-logitech-dj.h
+++ b/drivers/hid/hid-logitech-dj.h
@@ -101,6 +101,7 @@ struct dj_receiver_dev {
 	struct work_struct work;
 	struct kfifo notif_fifo;
 	spinlock_t lock;
+	bool querying_devices;
 };
 
 struct dj_device {
-- 
1.7.5.3


^ permalink raw reply related	[flat|nested] 7+ messages in thread
end of thread, other threads:[~2012-10-09 10:16 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-09-21 10:21 [PATCH 1/1] HID: Fix missing Unifying device issue Nestor Lopez Casado
2012-09-22  7:50 ` Jiri Kosina
2012-09-22 20:47   ` Jiri Kosina
2012-09-23 10:23 ` Josip Rodin
     [not found]   ` <CAE7qMroQOxo7kci7roLbS5HXjpkyhRi=cj1WCoYtAPB328xNQg@mail.gmail.com>
2012-09-27  7:04     ` Josip Rodin
2012-09-27 18:56       ` Josip Rodin
     [not found]         ` <CAE7qMrrjeMBzfofaY+2O4CAh3OSDaK3fDe_c8Hh8Y2web7kUqQ@mail.gmail.com>
     [not found]           ` <50732C91.20005@gmail.com>
2012-10-09 10:15             ` Nestor Lopez Casado

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