On Mon, Jun 08, 2015 at 02:51:37PM -0500, Peter E. Berger wrote:
> From: "Peter E. Berger" <pberger@xxxxxxxxxxx>
>
> When using newer Edgeport devices such as the EP/416, idle ports are
> automatically bounced (disconnected and then reconnected) approximately
> every 60 seconds. This breaks programs (e.g: minicom) where idle periods
> are common, normal and expected.
>
> I confirmed with the manufacturer (Digi International) that some Edgeports
> now ship from the factory with firmware that expects periodic "heartbeat"
> queries from the driver to keep idle ports alive. This patch implements
> heartbeat support using the mechanism Digi suggested (periodically
> requesting an I2C descriptor address) that appears effective on Edgeports
> running the newer firmware (that require it) and benign on Edgeport
> devices running older firmware. Since we know that Edgeport firmware
> version 4.80 (the version distributed in /lib/firmware/down3.bin and used
> for Edgeports that are either running still older versions or have no
> onboard non-volatile firmware image) does not require heartbeat support,
> this patch only schedules heartbeats on devices running firmware versions
> newer than 4.80.
>
> Signed-off-by: Peter E. Berger <pberger@xxxxxxxxxxx>
> ---
> drivers/usb/serial/io_ti.c | 81 +++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 80 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c
> index 00e1034..4dd3648 100644
> --- a/drivers/usb/serial/io_ti.c
> +++ b/drivers/usb/serial/io_ti.c
> @@ -101,6 +101,7 @@ struct edgeport_serial {
> struct mutex es_lock;
> int num_ports_open;
> struct usb_serial *serial;
> + struct delayed_work heartbeat_work;
> int fw_version;
> };
>
> @@ -206,6 +207,18 @@ static void edge_send(struct usb_serial_port *port, struct tty_struct *tty);
> static int edge_create_sysfs_attrs(struct usb_serial_port *port);
> static int edge_remove_sysfs_attrs(struct usb_serial_port *port);
>
> +/*
> + * Some release of Edgeport firmware "down3.bin" after version 4.80
> + * introduced code to automatically disconnect idle or closed devices
> + * after periods of inactivity, typically ~60 seconds. Digi International
> + * Tech Support suggests adding driver "heartbeat" code to reset the
> + * firmware timer by requesting a descriptor record every 15 seconds,
> + * which should be effective with newer firmware versions that require
> + * it, and benign with older versions that do not. In practice 40 seconds
> + * seems often enough.
> + */
> +#define FW_HEARTBEAT_VERSION_CUTOFF ((4<<8) + 80)
Add spaces around <<
> +#define FW_HEARTBEAT_SECS 40
>
> static int ti_vread_sync(struct usb_device *dev, __u8 request,
> __u16 value, __u16 index, u8 *data, int size)
> @@ -2351,6 +2364,28 @@ static void edge_break(struct tty_struct *tty, int break_state)
> __func__, status);
> }
>
> +static void edge_heartbeat_work(struct work_struct *taskp)
Call the argument "work" as well.
> +{
> + struct edgeport_serial *serial;
> + struct ti_i2c_desc *rom_desc;
> +
> + serial = container_of(taskp, struct edgeport_serial,
> + heartbeat_work.work);
> +
> + rom_desc = kmalloc(sizeof(*rom_desc), GFP_KERNEL);
> +
> + /* Descriptor address request is enough to reset the firmware timer */
> + if (!rom_desc || !get_descriptor_addr(serial, I2C_DESC_TYPE_ION,
> + rom_desc)) {
> + dev_warn(&serial->serial->interface->dev,
> + "%s - Incomplete heartbeat.", __func__);
Missing '\n' on error message (and skip the period).
Use dev_err.
> + }
> + kfree(rom_desc);
> +
> + schedule_delayed_work(&serial->heartbeat_work, FW_HEARTBEAT_SECS * HZ);
> +
Stray newline.
> +}
> +
> static int edge_startup(struct usb_serial *serial)
> {
> struct edgeport_serial *edge_serial;
> @@ -2362,6 +2397,8 @@ static int edge_startup(struct usb_serial *serial)
> u8 fw_major_version;
> u8 fw_minor_version;
>
> + dev_dbg(&serial->interface->dev, "%s: serial:%s\n", __func__,
> + serial->dev->serial);
Drop this one.
> /* create our private serial structure */
> edge_serial = kzalloc(sizeof(struct edgeport_serial), GFP_KERNEL);
> if (!edge_serial)
> @@ -2392,6 +2429,13 @@ static int edge_startup(struct usb_serial *serial)
> return status;
> }
>
> + if (edge_serial->fw_version > FW_HEARTBEAT_VERSION_CUTOFF) {
> + INIT_DELAYED_WORK(&edge_serial->heartbeat_work,
> + edge_heartbeat_work);
Init unconditionally.
> + schedule_delayed_work(&edge_serial->heartbeat_work,
> + FW_HEARTBEAT_SECS * HZ);
But only schedule if > cutoff-version, possibly refactor that to an
inline helper function edge_heartbeat_reschedule().
> + }
> +
> return 0;
> }
>
> @@ -2401,7 +2445,11 @@ static void edge_disconnect(struct usb_serial *serial)
>
> static void edge_release(struct usb_serial *serial)
> {
> - kfree(usb_get_serial_data(serial));
> + struct edgeport_serial *edge_serial = usb_get_serial_data(serial);
> +
> + if (edge_serial->fw_version > FW_HEARTBEAT_VERSION_CUTOFF)
> + cancel_delayed_work_sync(&edge_serial->heartbeat_work);
Cancel unconditionally.
> + kfree(edge_serial);
> }
>
> static int edge_port_probe(struct usb_serial_port *port)
> @@ -2505,6 +2553,29 @@ static int edge_remove_sysfs_attrs(struct usb_serial_port *port)
> return 0;
> }
>
> +#ifdef CONFIG_PM
> +static int edge_suspend(struct usb_serial *serial, pm_message_t message)
> +{
> + struct edgeport_serial *edge_serial = usb_get_serial_data(serial);
> +
> + if (edge_serial->fw_version > FW_HEARTBEAT_VERSION_CUTOFF)
> + cancel_delayed_work_sync(&edge_serial->heartbeat_work);
Same here.
> +
> + return 0;
> +}
> +
> +static int edge_resume(struct usb_serial *serial)
> +{
> + struct edgeport_serial *edge_serial = usb_get_serial_data(serial);
> +
> + if (edge_serial->fw_version > FW_HEARTBEAT_VERSION_CUTOFF) {
> + schedule_delayed_work(&edge_serial->heartbeat_work,
> + FW_HEARTBEAT_SECS * HZ);
> + }
Use helper here as well.
> +
> + return 0;
> +}
> +#endif
Thanks,
Johan
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
