Commit 1c1813a7 authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Jiri Kosina
Browse files

HID: core: statically allocate read buffers 



This is a preparation patch for rethinking the generic processing
of HID reports.

We can actually pre-allocate all of our memory instead of dynamically
allocating/freeing it whenever we parse a report.

Signed-off-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: default avatarPing Cheng <ping.cheng@wacom.com>
Acked-by: default avatarPeter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent a254a9da

drivers/hid/hid-core.c

+5 −7
Original line number Diff line number Diff line
@@ -101,7 +101,7 @@ static struct hid_field *hid_register_field(struct hid_report *report, unsigned 


	field = kzalloc((sizeof(struct hid_field) +

			 usages * sizeof(struct hid_usage) +

			 usages * sizeof(unsigned)), GFP_KERNEL);

			 2 * usages * sizeof(unsigned int)), GFP_KERNEL);

	if (!field)

		return NULL;
@@ -109,6 +109,7 @@ static struct hid_field *hid_register_field(struct hid_report *report, unsigned 
	report->field[field->index] = field;

	field->usage = (struct hid_usage *)(field + 1);

	field->value = (s32 *)(field->usage + usages);

	field->new_value = (s32 *)(field->value + usages);

	field->report = report;



	return field;
@@ -1541,9 +1542,8 @@ static void hid_input_field(struct hid_device *hid, struct hid_field *field, 
	__s32 max = field->logical_maximum;

	__s32 *value;



	value = kmalloc_array(count, sizeof(__s32), GFP_ATOMIC);

	if (!value)

		return;

	value = field->new_value;

	memset(value, 0, count * sizeof(__s32));



	for (n = 0; n < count; n++) {
@@ -1557,7 +1557,7 @@ static void hid_input_field(struct hid_device *hid, struct hid_field *field, 
		    value[n] >= min && value[n] <= max &&

		    value[n] - min < field->maxusage &&

		    field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1)

			goto exit;

			return;

	}



	for (n = 0; n < count; n++) {
@@ -1581,8 +1581,6 @@ static void hid_input_field(struct hid_device *hid, struct hid_field *field, 
	}



	memcpy(field->value, value, count * sizeof(__s32));

exit:

	kfree(value);

}



/*

include/linux/hid.h

+1 −0
Original line number Diff line number Diff line
@@ -476,6 +476,7 @@ struct hid_field { 
	unsigned  report_count;		/* number of this field in the report */

	unsigned  report_type;		/* (input,output,feature) */

	__s32    *value;		/* last known value(s) */

	__s32    *new_value;		/* newly read value(s) */

	__s32     logical_minimum;

	__s32     logical_maximum;

	__s32     physical_minimum;