On Thu, Aug 18, 2016 at 03:46:47PM -0700, Tony Lindgren wrote:
> We want to keep musb enabled always when the session bit is
> set. This simplifies the PM runtime and allows making it more
> generic across the various glue layers.
>
> So far the only exception to just following the session bit is
> host mode disconnect where the session bit stays set.
>
> In that case, just allow PM and let the PM runtime autoidle
> timeout deal with it.
>
> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
> ---
> drivers/usb/musb/musb_core.c | 70 ++++++++++++++++++++++++++++++++++++++++++++
> drivers/usb/musb/musb_core.h | 1 +
> 2 files changed, 71 insertions(+)
>
> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
> index 74fc306..9c4e1a5 100644
> --- a/drivers/usb/musb/musb_core.c
> +++ b/drivers/usb/musb/musb_core.c
> @@ -1831,11 +1831,81 @@ static const struct attribute_group musb_attr_group = {
> .attrs = musb_attributes,
> };
>
> +#define MUSB_QUIRK_B_INVALID_VBUS_91 (MUSB_DEVCTL_BDEVICE | \
> + (2 << MUSB_DEVCTL_VBUS_SHIFT) | \
> + MUSB_DEVCTL_SESSION)
> +#define MUSB_QUIRK_A_DISCONNECT_19 ((3 << MUSB_DEVCTL_VBUS_SHIFT) | \
> + MUSB_DEVCTL_SESSION)
> +
> +/*
> + * Check the musb devctl session bit to determine if we want to
> + * allow PM runtime for the device. In general, we want to keep things
> + * active when the session bit is set except after host disconnect.
> + *
> + * Only called from musb_irq_work. If this ever needs to get called
> + * elsewhere, proper locking must be implemented for musb->session.
> + */
> +static void musb_pm_runtime_check_session(struct musb *musb)
> +{
> + u8 devctl, s;
> + int error;
> +
> + devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
> +
> + /* Handle session status quirks first */
> + s = MUSB_DEVCTL_FSDEV | MUSB_DEVCTL_LSDEV |
> + MUSB_DEVCTL_HR;
> + switch (devctl & ~s) {
> + case MUSB_QUIRK_B_INVALID_VBUS_91:
> + if (musb->session)
> + break;
> + dev_dbg(musb->controller,
> + "Allow PM as device with invalid vbus: %02x\n",
> + devctl);
> + return;
> + case MUSB_QUIRK_A_DISCONNECT_19:
> + if (!musb->session)
> + break;
> + dev_dbg(musb->controller,
> + "Allow PM on possible host mode disconnect\n");
> + pm_runtime_mark_last_busy(musb->controller);
> + pm_runtime_put_autosuspend(musb->controller);
> + musb->session = false;
> + return;
> + default:
> + break;
> + }
> +
> + /* No need to do anything if session has not changed */
> + s = devctl & MUSB_DEVCTL_SESSION;
> + if (s == musb->session)
> + return;
> +
> + /* Block PM or allow PM? */
> + if (s) {
> + dev_dbg(musb->controller, "Block PM on active session: %02x\n",
> + devctl);
> + error = pm_runtime_get_sync(musb->controller);
> + if (error < 0)
> + dev_err(musb->controller, "Could not enable: %i\n",
> + error);
> + } else {
> + dev_dbg(musb->controller, "Allow PM with no session: %02x\n",
> + devctl);
I changed dev_dbg() to musb_dbg(). musb core already moves to
tracepoints for debug.
> + pm_runtime_mark_last_busy(musb->controller);
> + pm_runtime_put_autosuspend(musb->controller);
> + }
> +
> + musb->session = s;
> +}
> +
> /* Only used to provide driver mode change events */
> static void musb_irq_work(struct work_struct *data)
> {
> struct musb *musb = container_of(data, struct musb, irq_work);
>
> + musb_pm_runtime_check_session(musb);
> +
> if (musb->xceiv->otg->state != musb->xceiv_old_state) {
> musb->xceiv_old_state = musb->xceiv->otg->state;
> sysfs_notify(&musb->controller->kobj, NULL, "mode");
> diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h
> index b55a776..65288a5 100644
> --- a/drivers/usb/musb/musb_core.h
> +++ b/drivers/usb/musb/musb_core.h
> @@ -378,6 +378,7 @@ struct musb {
> u8 min_power; /* vbus for periph, in mA/2 */
>
> int port_mode; /* MUSB_PORT_MODE_* */
> + bool session;
> bool is_host;
>
> int a_wait_bcon; /* VBUS timeout in msecs */
> --
> 2.8.1
>
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