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HID: logitech-dj: add logi_dj_recv_queue_unknown_work helper

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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: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
This commit is contained in:
Hans de Goede 2019-04-20 13:21:53 +02:00 committed by Benjamin Tissoires
parent a1d97ccbb4
commit b6aeeddef6
1 changed files with 30 additions and 15 deletions
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45
drivers/hid/hid-logitech-dj.c
View file

@ -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;