From: Jason Gerecke <jason.gerecke@xxxxxxxxx>
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: Jason Gerecke <jason.gerecke@xxxxxxxxx>
---
drivers/hid/wacom_sys.c | 35 +++++++++++++++++++++--------------
drivers/hid/wacom_wac.c | 8 ++++----
drivers/hid/wacom_wac.h | 7 ++-----
3 files changed, 27 insertions(+), 23 deletions(-)
diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c
index 8125383932ec7..97393a3083cae 100644
--- a/drivers/hid/wacom_sys.c
+++ b/drivers/hid/wacom_sys.c
@@ -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;
diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index b60bfafc6a8fb..5107a676e24fc 100644
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -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;
}
diff --git a/drivers/hid/wacom_wac.h b/drivers/hid/wacom_wac.h
index 0c3c6a6aaae95..02327de63841a 100644
--- a/drivers/hid/wacom_wac.h
+++ b/drivers/hid/wacom_wac.h
@@ -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];
--
2.48.1
