Hi
On Tue, Feb 18, 2014 at 11:22 PM, Frank Praznik <frank.praznik@xxxxxxxxx> wrote:
> If a Sixaxis or Dualshock 4 controller is connected via USB while already
> connected via Bluetooth it will cause duplicate devices to be added to the
> input device list.
>
> To prevent this a global list of controllers and their MAC addresses is
> maintained and new controllers are checked against this list. If a duplicate
> is found, the probe function with exit with -EEXIST.
>
> On USB the MAC is retrieved via a feature report. On Bluetooth neither
> controller reports the MAC address in a feature report so the MAC is parsed from
> the uniq string. As uniq cannot be guaranteed to be a MAC address in every case
> (uHID or the behavior of HIDP changing) a parsing failure will not prevent the
> connection.
>
> Signed-off-by: Frank Praznik <frank.praznik@xxxxxxxxx>
> ---
> drivers/hid/hid-sony.c | 165 +++++++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 159 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/hid/hid-sony.c b/drivers/hid/hid-sony.c
> index ad1cebd..c25f0d7 100644
> --- a/drivers/hid/hid-sony.c
> +++ b/drivers/hid/hid-sony.c
> @@ -713,8 +713,12 @@ static enum power_supply_property sony_battery_props[] = {
> POWER_SUPPLY_PROP_STATUS,
> };
>
> +static spinlock_t sony_dev_list_lock;
> +static LIST_HEAD(sony_device_list);
Please include <linux/list.h>
> +
> struct sony_sc {
> spinlock_t lock;
> + struct list_head list_node;
> struct hid_device *hdev;
> struct led_classdev *leds[MAX_LEDS];
> unsigned long quirks;
> @@ -726,6 +730,7 @@ struct sony_sc {
> __u8 right;
> #endif
>
> + __u8 mac_address[6];
> __u8 cable_state;
> __u8 battery_charging;
> __u8 battery_capacity;
> @@ -1473,6 +1478,137 @@ static int sony_register_touchpad(struct sony_sc *sc, int touch_count,
> return 0;
> }
>
> +/* If a controller is plugged in via USB while already connected via Bluetooth
> + * it will show up as two devices. A global list of connected controllers and
> + * their MAC addresses is maintained to ensure that a device is only connected
> + * once.
> + */
We usually use one of those comment-styles:
/*
* some
* comment
*/
/* some
* comment */
..but I use my own style all the time, so who am I to judge.. You
might get screamed at in other subsystems, though.
> +static int sony_check_add_dev_list(struct sony_sc *sc)
> +{
> + struct sony_sc *entry;
> + struct list_head *pos;
> + unsigned long flags;
> + int ret;
> +
> + spin_lock_irqsave(&sony_dev_list_lock, flags);
> +
> + list_for_each(pos, &sony_device_list) {
> + entry = list_entry(pos, struct sony_sc, list_node);
You can use "list_for_each_entry()" here.
> + ret = memcmp(sc->mac_address, entry->mac_address,
> + sizeof(sc->mac_address));
> + if (!ret) {
> + if (sc->hdev->bus != entry->hdev->bus) {
> + ret = -EEXIST;
> + hid_info(sc->hdev, "controller with MAC address %pMR already connected\n",
> + sc->mac_address);
> + } else {
> + /* Duplicate found, but on the same bus as the
> + * original. Allow the connection in this case.
> + */
> + ret = 0;
Please drop that. Imagine some device uses BT-LE at some point and
thus is managed via uHID. If the device is connected via BT *and*
BT-LE, both will have BUS_BLUETOOTH set but are the same device. I
think the mac-comparison is enough. I don't know why a single device
would be connected twice and be managed by hid-sony..
> + }
> +
> + spin_unlock_irqrestore(&sony_dev_list_lock, flags);
> + return ret;
Usually we use:
r = -ESOMETHING;
goto unlock;
...
r = 0;
unlock:
spin_unlock_irqrestore(&sony_dev_list_lock, flags);
return r;
This way the locking is symmetric and easier to review.
> + }
> + }
> +
> + list_add(&(sc->list_node), &sony_device_list);
> + spin_unlock_irqrestore(&sony_dev_list_lock, flags);
> +
> + return 0;
> +}
> +
> +static void sony_remove_dev_list(struct sony_sc *sc)
> +{
> + unsigned long flags;
> +
> + if (sc->list_node.next) {
> + spin_lock_irqsave(&sony_dev_list_lock, flags);
> + list_del(&(sc->list_node));
> + spin_unlock_irqrestore(&sony_dev_list_lock, flags);
> + }
> +}
> +
> +static int sony_get_bt_devaddr(struct sony_sc *sc)
> +{
> + int ret, n;
> + unsigned int mac_addr[6];
> +
> + /* HIDP stores the device MAC address as a string in the uniq field. */
> + ret = strlen(sc->hdev->uniq);
Are you sure "uniq" cannot be NULL?
> + if (ret != 17)
> + return -EINVAL;
> +
> + ret = sscanf(sc->hdev->uniq, "%02x:%02x:%02x:%02x:%02x:%02x",
> + &mac_addr[5], &mac_addr[4], &mac_addr[3], &mac_addr[2],
> + &mac_addr[1], &mac_addr[0]);
%02hhx so you can avoid the temporary copy?
> +
> + if (ret != 6)
> + return -EINVAL;
> +
> + for (n = 0; n < 6; n++)
> + sc->mac_address[n] = (__u8)mac_addr[n];
> +
> + return 0;
> +}
> +
> +static int sony_check_add(struct sony_sc *sc)
> +{
> + int n, ret;
> +
> + if ((sc->quirks & DUALSHOCK4_CONTROLLER_BT) ||
> + (sc->quirks & SIXAXIS_CONTROLLER_BT)) {
> + /* sony_get_bt_devaddr() attempts to parse the Bluetooth MAC
> + * address from the uniq string where HIDP stores it.
> + * As uniq cannot be guaranteed to be a MAC address in all cases
> + * a failure of this function should not prevent the connection.
> + */
> + if (sony_get_bt_devaddr(sc) < 0) {
> + hid_warn(sc->hdev, "UNIQ does not contain a MAC address; duplicate check skipped\n");
> + return 0;
> + }
> + } else if (sc->quirks & DUALSHOCK4_CONTROLLER_USB) {
> + __u8 buf[7];
> +
> + /* The MAC address of a DS4 controller connected via USB can be
> + * retrieved with feature report 0x81. The address begins at
> + * offset 1.
> + */
> + ret = hid_hw_raw_request(sc->hdev, 0x81, buf, sizeof(buf),
> + HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
> +
> + if (ret != 7) {
> + hid_err(sc->hdev, "failed to retrieve feature report 0x81 with the DualShock 4 MAC address\n");
> + return ret < 0 ? ret : -EINVAL;
> + }
> +
> + memcpy(sc->mac_address, &buf[1], sizeof(sc->mac_address));
> + } else if (sc->quirks & SIXAXIS_CONTROLLER_USB) {
> + __u8 buf[18];
> +
> + /* The MAC address of a Sixaxis controller connected via USB can
> + * be retrieved with feature report 0xf2. The address begins at
> + * offset 4.
> + */
> + ret = hid_hw_raw_request(sc->hdev, 0xf2, buf, sizeof(buf),
> + HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
> +
> + if (ret != 18) {
> + hid_err(sc->hdev, "failed to retrieve feature report 0xf2 with the Sixaxis MAC address\n");
> + return ret < 0 ? ret : -EINVAL;
> + }
> +
> + /* The Sixaxis device MAC in the report is in reverse order */
"reverse" sounds weird here.. addresses are usually stored in
network-byte-order (BigEndian), so lets be clear here and say the
input is little-endian so you have to swap it. Or am I wrong?
> + for (n = 0; n < 6; n++)
> + sc->mac_address[5-n] = buf[4+n];
> + } else {
> + return 0;
> + }
> +
> + return sony_check_add_dev_list(sc);
> +}
> +
> static int sony_probe(struct hid_device *hdev, const struct hid_device_id *id)
> {
> int ret;
> @@ -1509,12 +1645,22 @@ static int sony_probe(struct hid_device *hdev, const struct hid_device_id *id)
> return ret;
> }
>
> - if (sc->quirks & SIXAXIS_CONTROLLER_USB) {
> - hdev->hid_output_raw_report = sixaxis_usb_output_raw_report;
> - ret = sixaxis_set_operational_usb(hdev);
> - INIT_WORK(&sc->state_worker, sixaxis_state_worker);
> - } else if (sc->quirks & SIXAXIS_CONTROLLER_BT) {
> - ret = sixaxis_set_operational_bt(hdev);
> + if (sc->quirks & SIXAXIS_CONTROLLER) {
> + if (sc->quirks & SIXAXIS_CONTROLLER_USB) {
> + hdev->hid_output_raw_report = sixaxis_usb_output_raw_report;
> + ret = sixaxis_set_operational_usb(hdev);
> + } else
> + ret = sixaxis_set_operational_bt(hdev);
> +
> + if (ret < 0) {
> + hid_err(hdev, "failed to set the Sixaxis operational mode\n");
> + goto err_stop;
> + }
> +
> + ret = sony_check_add(sc);
> + if (ret < 0)
> + goto err_stop;
> +
You check the quirks in sony_check_add() again, so why not leave all
this code as is and call sony_check_add() below for *all* devices?
Could you add a line to net/hidp/core.c where we write UNIQ that some
devices depend on this? Other than that, the patch looks good.
Thanks
David
> INIT_WORK(&sc->state_worker, sixaxis_state_worker);
> } else if (sc->quirks & DUALSHOCK4_CONTROLLER) {
> if (sc->quirks & DUALSHOCK4_CONTROLLER_BT) {
> @@ -1524,6 +1670,11 @@ static int sony_probe(struct hid_device *hdev, const struct hid_device_id *id)
> goto err_stop;
> }
> }
> +
> + ret = sony_check_add(sc);
> + if (ret < 0)
> + goto err_stop;
> +
> /* The Dualshock 4 touchpad supports 2 touches and has a
> * resolution of 1920x940.
> */
> @@ -1588,6 +1739,8 @@ static void sony_remove(struct hid_device *hdev)
> sony_battery_remove(sc);
> }
>
> + sony_remove_dev_list(sc);
> +
> cancel_work_sync(&sc->state_worker);
>
> hid_hw_stop(hdev);
> --
> 1.8.5.3
>
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