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Date: Wed, 15 May 2013 09:37:52 +0200
From: Libor Pechacek <lpechacek@...e.cz>
To: Jiri Slaby <jslaby@...e.cz>
Cc: jkosina@...e.cz, jirislaby@...il.com, linux-kernel@...r.kernel.org,
Petr Ostadal <postadal@...e.cz>,
Oliver Neukum <oliver@...kum.org>,
Vojtech Pavlik <vojtech@...e.cz>, Egbert Eich <eich@...e.com>
Subject: Re: [PATCH 2/2] HID: elo-hid, add quirks for broken firmware
On Tue 07-05-13 11:40:59, Jiri Slaby wrote:
> One firmare version in the devices the driver takes care of is
> completely broken and needs periodic pokes from our side. We
> implemented this as a periodic delayed queue. The idea of the pokes
> was taken from the suse enterprise kernel, in particular from Libor's
> "Elo touchscreen firmware M workaround".
>
> I am quoting him here:
> This patch adds periodic polling of the Elo USB touchscreens. Needed
> as a workaround for devices with M-level firmware, otherwise these
> devices are known to misbehave (as reported by Elo developers).
>
> [v2]
> - allocate the buffer only once (per Oliver)
> - add use_fw_quirk module parameter (per Libor)
Thanks, looks OK to me.
Libor
> Signed-off-by: Jiri Slaby <jslaby@...e.cz>
> Cc: Petr Ostadal <postadal@...e.cz>
> Cc: Oliver Neukum <oliver@...kum.org>
> Cc: Vojtech Pavlik <vojtech@...e.cz>
> Cc: Egbert Eich <eich@...e.com>
> Cc: Libor Pechacek <lpechacek@...e.cz>
> ---
> drivers/hid/hid-elo.c | 144 +++++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 143 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hid/hid-elo.c b/drivers/hid/hid-elo.c
> index 56143e0..f042a6c 100644
> --- a/drivers/hid/hid-elo.c
> +++ b/drivers/hid/hid-elo.c
> @@ -11,9 +11,32 @@
> #include <linux/hid.h>
> #include <linux/input.h>
> #include <linux/module.h>
> +#include <linux/usb.h>
> +#include <linux/workqueue.h>
>
> #include "hid-ids.h"
>
> +#define ELO_PERIODIC_READ_INTERVAL HZ
> +#define ELO_SMARTSET_CMD_TIMEOUT 2000 /* msec */
> +
> +/* Elo SmartSet commands */
> +#define ELO_FLUSH_SMARTSET_RESPONSES 0x02 /* Flush all pending smartset responses */
> +#define ELO_SEND_SMARTSET_COMMAND 0x05 /* Send a smartset command */
> +#define ELO_GET_SMARTSET_RESPONSE 0x06 /* Get a smartset response */
> +#define ELO_DIAG 0x64 /* Diagnostics command */
> +#define ELO_SMARTSET_PACKET_SIZE 8
> +
> +struct elo_priv {
> + struct usb_device *usbdev;
> + struct delayed_work work;
> + unsigned char buffer[ELO_SMARTSET_PACKET_SIZE];
> +};
> +
> +static struct workqueue_struct *wq;
> +static bool use_fw_quirk = true;
> +module_param(use_fw_quirk, bool, S_IRUGO);
> +MODULE_PARM_DESC(use_fw_quirk, "Do periodic pokes for broken M firmwares (default = true)");
> +
> static void elo_input_configured(struct hid_device *hdev,
> struct hid_input *hidinput)
> {
> @@ -73,10 +96,108 @@ static int elo_raw_event(struct hid_device *hdev, struct hid_report *report,
> return 0;
> }
>
> +static int elo_smartset_send_get(struct usb_device *dev, u8 command,
> + void *data)
> +{
> + unsigned int pipe;
> + u8 dir;
> +
> + if (command == ELO_SEND_SMARTSET_COMMAND) {
> + pipe = usb_sndctrlpipe(dev, 0);
> + dir = USB_DIR_OUT;
> + } else if (command == ELO_GET_SMARTSET_RESPONSE) {
> + pipe = usb_rcvctrlpipe(dev, 0);
> + dir = USB_DIR_IN;
> + } else
> + return -EINVAL;
> +
> + return usb_control_msg(dev, pipe, command,
> + dir | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
> + 0, 0, data, ELO_SMARTSET_PACKET_SIZE,
> + ELO_SMARTSET_CMD_TIMEOUT);
> +}
> +
> +static int elo_flush_smartset_responses(struct usb_device *dev)
> +{
> + return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
> + ELO_FLUSH_SMARTSET_RESPONSES,
> + USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
> + 0, 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
> +}
> +
> +static void elo_work(struct work_struct *work)
> +{
> + struct elo_priv *priv = container_of(work, struct elo_priv, work.work);
> + struct usb_device *dev = priv->usbdev;
> + unsigned char *buffer = priv->buffer;
> + int ret;
> +
> + ret = elo_flush_smartset_responses(dev);
> + if (ret < 0) {
> + dev_err(&dev->dev, "initial FLUSH_SMARTSET_RESPONSES failed, error %d\n",
> + ret);
> + goto fail;
> + }
> +
> + /* send Diagnostics command */
> + *buffer = ELO_DIAG;
> + ret = elo_smartset_send_get(dev, ELO_SEND_SMARTSET_COMMAND, buffer);
> + if (ret < 0) {
> + dev_err(&dev->dev, "send Diagnostics Command failed, error %d\n",
> + ret);
> + goto fail;
> + }
> +
> + /* get the result */
> + ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE, buffer);
> + if (ret < 0) {
> + dev_err(&dev->dev, "get Diagnostics Command response failed, error %d\n",
> + ret);
> + goto fail;
> + }
> +
> + /* read the ack */
> + if (*buffer != 'A') {
> + ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE,
> + buffer);
> + if (ret < 0) {
> + dev_err(&dev->dev, "get acknowledge response failed, error %d\n",
> + ret);
> + goto fail;
> + }
> + }
> +
> +fail:
> + ret = elo_flush_smartset_responses(dev);
> + if (ret < 0)
> + dev_err(&dev->dev, "final FLUSH_SMARTSET_RESPONSES failed, error %d\n",
> + ret);
> + queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
> +}
> +
> +/*
> + * Not all Elo devices need the periodic HID descriptor reads.
> + * Only firmware version M needs this.
> + */
> +static bool elo_broken_firmware(struct usb_device *dev)
> +{
> + return use_fw_quirk && le16_to_cpu(dev->descriptor.bcdDevice) == 0x10d;
> +}
> +
> static int elo_probe(struct hid_device *hdev, const struct hid_device_id *id)
> {
> + struct elo_priv *priv;
> int ret;
>
> + priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + INIT_DELAYED_WORK(&priv->work, elo_work);
> + priv->usbdev = interface_to_usbdev(to_usb_interface(hdev->dev.parent));
> +
> + hid_set_drvdata(hdev, priv);
> +
> ret = hid_parse(hdev);
> if (ret) {
> hid_err(hdev, "parse failed\n");
> @@ -89,14 +210,24 @@ static int elo_probe(struct hid_device *hdev, const struct hid_device_id *id)
> goto err_free;
> }
>
> + if (elo_broken_firmware(priv->usbdev)) {
> + hid_info(hdev, "broken firmware found, installing workaround\n");
> + queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
> + }
> +
> return 0;
> err_free:
> + kfree(priv);
> return ret;
> }
>
> static void elo_remove(struct hid_device *hdev)
> {
> + struct elo_priv *priv = hid_get_drvdata(hdev);
> +
> hid_hw_stop(hdev);
> + flush_workqueue(wq);
> + kfree(priv);
> }
>
> static const struct hid_device_id elo_devices[] = {
> @@ -117,13 +248,24 @@ static struct hid_driver elo_driver = {
>
> static int __init elo_driver_init(void)
> {
> - return hid_register_driver(&elo_driver);
> + int ret;
> +
> + wq = create_singlethread_workqueue("elousb");
> + if (!wq)
> + return -ENOMEM;
> +
> + ret = hid_register_driver(&elo_driver);
> + if (ret)
> + destroy_workqueue(wq);
> +
> + return ret;
> }
> module_init(elo_driver_init);
>
> static void __exit elo_driver_exit(void)
> {
> hid_unregister_driver(&elo_driver);
> + destroy_workqueue(wq);
> }
> module_exit(elo_driver_exit);
>
> --
> 1.8.2.1
>
--
Libor Pechacek
Project Manager SUSE Labs, Prague
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