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Commit b6aeedde authored by Hans de Goede's avatar Hans de Goede Committed by Benjamin Tissoires
Browse files

HID: logitech-dj: add logi_dj_recv_queue_unknown_work helper 



Add a logi_dj_recv_queue_unknown_work helper and implement query
rate-limiting inside this helper.

The motivations behind this are:

1) We need to queue workitems for reports with no place to forward them
from more places with the upcoming non-unifying receiver support, hence
the addition of the helper function.

2) When we've missed a pairing info report (or there is a race between
the report and input-events) and the input report is e.g. from a mouse
being moved, we will get a lot of these before we've finished (re-)
querying and enumerating the devices, hence the rate-limiting.

Note this also removes the:

if (!djrcv_dev->paired_dj_devices[hidpp_report->device_index])

check previously guarding the sending of an unknown workitem, the caller
of logi_dj_recv_queue_notification already does this check before calling
logi_dj_recv_queue_notification.

Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
parent a1d97ccb

drivers/hid/hid-logitech-dj.c

+30 −15
Original line number Diff line number Diff line
@@ -128,6 +128,7 @@ struct dj_receiver_dev { 
	struct kref kref;

	struct work_struct work;

	struct kfifo notif_fifo;

	unsigned long last_query; /* in jiffies */

	bool ready;

	spinlock_t lock;

};
@@ -458,6 +459,7 @@ static struct dj_receiver_dev *dj_get_receiver_dev(struct hid_device *hdev, 
		}

		kref_init(&djrcv_dev->kref);

		list_add_tail(&djrcv_dev->list, &dj_hdev_list);

		djrcv_dev->last_query = jiffies;

	}



	if (application == HID_GD_KEYBOARD)
@@ -637,6 +639,30 @@ static void delayedwork_callback(struct work_struct *work) 
	}

}



/*

 * Sometimes we receive reports for which we do not have a paired dj_device

 * associated with the device_index or report-type to forward the report to.

 * This means that the original "device paired" notification corresponding

 * to the dj_device never arrived to this driver. Possible reasons for this are:

 * 1) hid-core discards all packets coming from a device during probe().

 * 2) if the receiver is plugged into a KVM switch then the pairing reports

 * are only forwarded to it if the focus is on this PC.

 * This function deals with this by re-asking the receiver for the list of

 * connected devices in the delayed work callback.

 * This function MUST be called with djrcv->lock held.

 */

static void logi_dj_recv_queue_unknown_work(struct dj_receiver_dev *djrcv_dev)

{

	struct dj_workitem workitem = { .type = WORKITEM_TYPE_UNKNOWN };



	/* Rate limit queries done because of unhandeled reports to 2/sec */

	if (time_before(jiffies, djrcv_dev->last_query + HZ / 2))

		return;



	kfifo_in(&djrcv_dev->notif_fifo, &workitem, sizeof(workitem));

	schedule_work(&djrcv_dev->work);

}



static void logi_dj_recv_queue_notification(struct dj_receiver_dev *djrcv_dev,

					   struct dj_report *dj_report)

{
@@ -666,21 +692,8 @@ static void logi_dj_recv_queue_notification(struct dj_receiver_dev *djrcv_dev, 
			workitem.type = WORKITEM_TYPE_UNPAIRED;

		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 in

			 * the delayed work callback.

			 */

			workitem.type = WORKITEM_TYPE_UNKNOWN;

		}

		logi_dj_recv_queue_unknown_work(djrcv_dev);

		return;

	}



	kfifo_in(&djrcv_dev->notif_fifo, &workitem, sizeof(workitem));
@@ -776,6 +789,8 @@ static int logi_dj_recv_query_paired_devices(struct dj_receiver_dev *djrcv_dev) 
	struct dj_report *dj_report;

	int retval;



	djrcv_dev->last_query = jiffies;



	dj_report = kzalloc(sizeof(struct dj_report), GFP_KERNEL);

	if (!dj_report)

		return -ENOMEM;