Commit 5e013ad2 authored by Jason Gerecke's avatar Jason Gerecke Committed by Jiri Kosina
Browse files

HID: wacom: Remove static WACOM_PKGLEN_MAX limit 



Rather than memcpy every packet that we receive from HID into our own
local fixed-size array, we can just access the data directly through
the original pointer. While we're at it, remove the few other places
that assume a fixed maximum packet size and make them dynamic (in
particular: temporary buffers created by the wacom_wac_queue_flush and
wacom_intuos_bt_process_data functions; and the pen_fifo FIFO).

To ensure pen_fifo allocation has access to the maximum used packet
length, this commit also moves the function call to occur a little
later in the probe process.

Signed-off-by: default avatarJason Gerecke <jason.gerecke@wacom.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.com>
parent 58c9bf33

drivers/hid/wacom_sys.c

+21 −14
Original line number Diff line number Diff line
@@ -69,16 +69,27 @@ static void wacom_wac_queue_flush(struct hid_device *hdev, 
				  struct kfifo_rec_ptr_2 *fifo)

{

	while (!kfifo_is_empty(fifo)) {

		u8 buf[WACOM_PKGLEN_MAX];

		int size;

		int size = kfifo_peek_len(fifo);

		u8 *buf = kzalloc(size, GFP_KERNEL);

		unsigned int count;

		int err;



		size = kfifo_out(fifo, buf, sizeof(buf));

		count = kfifo_out(fifo, buf, size);

		if (count != size) {

			// Hard to say what is the "right" action in this

			// circumstance. Skipping the entry and continuing

			// to flush seems reasonable enough, however.

			hid_warn(hdev, "%s: removed fifo entry with unexpected size\n",

				 __func__);

			continue;

		}

		err = hid_report_raw_event(hdev, HID_INPUT_REPORT, buf, size, false);

		if (err) {

			hid_warn(hdev, "%s: unable to flush event due to error %d\n",

				 __func__, err);

		}



		kfree(buf);

	}

}
@@ -158,13 +169,10 @@ static int wacom_raw_event(struct hid_device *hdev, struct hid_report *report, 
	if (wacom->wacom_wac.features.type == BOOTLOADER)

		return 0;



	if (size > WACOM_PKGLEN_MAX)

		return 1;



	if (wacom_wac_pen_serial_enforce(hdev, report, raw_data, size))

		return -1;



	memcpy(wacom->wacom_wac.data, raw_data, size);

	wacom->wacom_wac.data = raw_data;



	wacom_wac_irq(&wacom->wacom_wac, size);
@@ -1286,6 +1294,7 @@ static void wacom_devm_kfifo_release(struct device *dev, void *res) 
static int wacom_devm_kfifo_alloc(struct wacom *wacom)

{

	struct wacom_wac *wacom_wac = &wacom->wacom_wac;

	int fifo_size = min(PAGE_SIZE, 10 * wacom_wac->features.pktlen);

	struct kfifo_rec_ptr_2 *pen_fifo;

	int error;
@@ -1296,7 +1305,7 @@ static int wacom_devm_kfifo_alloc(struct wacom *wacom) 
	if (!pen_fifo)

		return -ENOMEM;



	error = kfifo_alloc(pen_fifo, WACOM_PKGLEN_MAX, GFP_KERNEL);

	error = kfifo_alloc(pen_fifo, fifo_size, GFP_KERNEL);

	if (error) {

		devres_free(pen_fifo);

		return error;
@@ -2352,12 +2361,14 @@ static int wacom_parse_and_register(struct wacom *wacom, bool wireless) 
	unsigned int connect_mask = HID_CONNECT_HIDRAW;



	features->pktlen = wacom_compute_pktlen(hdev);

	if (features->pktlen > WACOM_PKGLEN_MAX)

		return -EINVAL;



	if (!devres_open_group(&hdev->dev, wacom, GFP_KERNEL))

		return -ENOMEM;



	error = wacom_devm_kfifo_alloc(wacom);

	if (error)

		goto fail;



	wacom->resources = true;



	error = wacom_allocate_inputs(wacom);
@@ -2821,10 +2832,6 @@ static int wacom_probe(struct hid_device *hdev, 
	if (features->check_for_hid_type && features->hid_type != hdev->type)

		return -ENODEV;



	error = wacom_devm_kfifo_alloc(wacom);

	if (error)

		return error;



	wacom_wac->hid_data.inputmode = -1;

	wacom_wac->mode_report = -1;

drivers/hid/wacom_wac.c

+4 −4
Original line number Diff line number Diff line
@@ -1201,12 +1201,10 @@ static void wacom_intuos_bt_process_data(struct wacom_wac *wacom, 


static int wacom_intuos_bt_irq(struct wacom_wac *wacom, size_t len)

{

	unsigned char data[WACOM_PKGLEN_MAX];

	u8 *data = kmemdup(wacom->data, len, GFP_KERNEL);

	int i = 1;

	unsigned power_raw, battery_capacity, bat_charging, ps_connected;



	memcpy(data, wacom->data, len);



	switch (data[0]) {

	case 0x04:

		wacom_intuos_bt_process_data(wacom, data + i);
@@ -1230,8 +1228,10 @@ static int wacom_intuos_bt_irq(struct wacom_wac *wacom, size_t len) 
		dev_dbg(wacom->pen_input->dev.parent,

				"Unknown report: %d,%d size:%zu\n",

				data[0], data[1], len);

		return 0;

		break;

	}



	kfree(data);

	return 0;

}

drivers/hid/wacom_wac.h

+2 −5
Original line number Diff line number Diff line
@@ -7,9 +7,6 @@ 
#include <linux/hid.h>

#include <linux/kfifo.h>



/* maximum packet length for USB/BT devices */

#define WACOM_PKGLEN_MAX	361



#define WACOM_NAME_MAX		64

#define WACOM_MAX_REMOTES	5

#define WACOM_STATUS_UNKNOWN	255
@@ -277,7 +274,7 @@ struct wacom_features { 
	unsigned touch_max;

	int oVid;

	int oPid;

	int pktlen;

	unsigned int pktlen;

	bool check_for_hid_type;

	int hid_type;

};
@@ -341,7 +338,7 @@ struct wacom_wac { 
	char pen_name[WACOM_NAME_MAX];

	char touch_name[WACOM_NAME_MAX];

	char pad_name[WACOM_NAME_MAX];

	unsigned char data[WACOM_PKGLEN_MAX];

	u8 *data;

	int tool[2];

	int id[2];

	__u64 serial[2];