There is no need to register an input device containing no events.
This allows drivers using the quirk MULTI_INPUT to register one input
per report effectively used.
For backward compatibility, we need to add a quirk to request
this behavior.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
---
drivers/hid/hid-input.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/hid.h | 1 +
2 files changed, 78 insertions(+)
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 21b196c..7aaf7d3 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -1198,6 +1198,67 @@ static struct hid_input *hidinput_allocate(struct hid_device *hid)
return hidinput;
}
+static bool hidinput_has_been_populated(struct hid_input *hidinput)
+{
+ int i;
+ bool r = 0;
+
+ for (i = 0; i < BITS_TO_LONGS(EV_CNT); i++)
+ r = r || hidinput->input->evbit[i];
+
+ for (i = 0; i < BITS_TO_LONGS(KEY_CNT); i++)
+ r = r || hidinput->input->keybit[i];
+
+ for (i = 0; i < BITS_TO_LONGS(REL_CNT); i++)
+ r = r || hidinput->input->relbit[i];
+
+ for (i = 0; i < BITS_TO_LONGS(ABS_CNT); i++)
+ r = r || hidinput->input->absbit[i];
+
+ for (i = 0; i < BITS_TO_LONGS(MSC_CNT); i++)
+ r = r || hidinput->input->mscbit[i];
+
+ for (i = 0; i < BITS_TO_LONGS(LED_CNT); i++)
+ r = r || hidinput->input->ledbit[i];
+
+ for (i = 0; i < BITS_TO_LONGS(SND_CNT); i++)
+ r = r || hidinput->input->sndbit[i];
+
+ for (i = 0; i < BITS_TO_LONGS(FF_CNT); i++)
+ r = r || hidinput->input->ffbit[i];
+
+ for (i = 0; i < BITS_TO_LONGS(SW_CNT); i++)
+ r = r || hidinput->input->swbit[i];
+
+ return !!r;
+}
+
+static void hidinput_cleanup_hidinput(struct hid_device *hid,
+ struct hid_input *hidinput)
+{
+ struct hid_report *report;
+ int i, k;
+
+ list_del(&hidinput->list);
+ input_free_device(hidinput->input);
+
+ for (k = HID_INPUT_REPORT; k <= HID_OUTPUT_REPORT; k++) {
+ if (k == HID_OUTPUT_REPORT &&
+ hid->quirks & HID_QUIRK_SKIP_OUTPUT_REPORTS)
+ continue;
+
+ list_for_each_entry(report, &hid->report_enum[k].report_list,
+ list) {
+
+ for (i = 0; i < report->maxfield; i++)
+ if (report->field[i]->hidinput == hidinput)
+ report->field[i]->hidinput = NULL;
+ }
+ }
+
+ kfree(hidinput);
+}
+
/*
* Register the input device; print a message.
* Configure the input layer interface
@@ -1249,6 +1310,10 @@ int hidinput_connect(struct hid_device *hid, unsigned int force)
hidinput_configure_usage(hidinput, report->field[i],
report->field[i]->usage + j);
+ if ((hid->quirks & HID_QUIRK_NO_EMPTY_INPUT) &&
+ !hidinput_has_been_populated(hidinput))
+ continue;
+
if (hid->quirks & HID_QUIRK_MULTI_INPUT) {
/* This will leave hidinput NULL, so that it
* allocates another one if we have more inputs on
@@ -1265,6 +1330,18 @@ int hidinput_connect(struct hid_device *hid, unsigned int force)
}
}
+ if (hidinput && (hid->quirks & HID_QUIRK_NO_EMPTY_INPUT) &&
+ !hidinput_has_been_populated(hidinput)) {
+ /* no need to register an input device not populated */
+ hidinput_cleanup_hidinput(hid, hidinput);
+ hidinput = NULL;
+ }
+
+ if (list_empty(&hid->inputs)) {
+ hid_err(hid, "No inputs registered, leaving\n");
+ goto out_unwind;
+ }
+
if (hidinput) {
if (drv->input_configured)
drv->input_configured(hid, hidinput);
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 7071eb3..15b98a6 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -282,6 +282,7 @@ struct hid_item {
#define HID_QUIRK_BADPAD 0x00000020
#define HID_QUIRK_MULTI_INPUT 0x00000040
#define HID_QUIRK_HIDINPUT_FORCE 0x00000080
+#define HID_QUIRK_NO_EMPTY_INPUT 0x00000100
#define HID_QUIRK_SKIP_OUTPUT_REPORTS 0x00010000
#define HID_QUIRK_FULLSPEED_INTERVAL 0x10000000
#define HID_QUIRK_NO_INIT_REPORTS 0x20000000
--
1.8.1.2
--
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