From 3725d8c97436aeaa03eeb0c25361a7ec0f3f5bd2 Mon Sep 17 00:00:00 2001 From: Inaky Perez-Gonzalez Date: Thu, 17 Sep 2009 15:20:45 -0700 Subject: [PATCH] wimax/i2400m: Implement pre/post reset support in the USB driver The USB stack can callback a driver is about to be reset by an external entity and right after it, so the driver can save state and then restore it. This commit implements said support; it is implemented actually in the core, bus-generic driver [i2400m_{pre,post}_reset()] and used by the bus-specific drivers. This way the SDIO driver can also use it once said support is brought to the SDIO stack. Signed-off-by: Inaky Perez-Gonzalez --- drivers/net/wimax/i2400m/driver.c | 81 +++++++++++++++++++++++++++++++ drivers/net/wimax/i2400m/i2400m.h | 2 + drivers/net/wimax/i2400m/usb.c | 33 +++++++++++++ 3 files changed, 116 insertions(+) diff --git a/drivers/net/wimax/i2400m/driver.c b/drivers/net/wimax/i2400m/driver.c index 4fcdb18261fd..1f6aa2a55429 100644 --- a/drivers/net/wimax/i2400m/driver.c +++ b/drivers/net/wimax/i2400m/driver.c @@ -619,6 +619,87 @@ int i2400m_pm_notifier(struct notifier_block *notifier, } +/* + * pre-reset is called before a device is going on reset + * + * This has to be followed by a call to i2400m_post_reset(), otherwise + * bad things might happen. + */ +int i2400m_pre_reset(struct i2400m *i2400m) +{ + int result; + struct device *dev = i2400m_dev(i2400m); + + d_fnstart(3, dev, "(i2400m %p)\n", i2400m); + d_printf(1, dev, "pre-reset shut down\n"); + + result = 0; + mutex_lock(&i2400m->init_mutex); + if (i2400m->updown) { + netif_tx_disable(i2400m->wimax_dev.net_dev); + __i2400m_dev_stop(i2400m); + result = 0; + /* down't set updown to zero -- this way + * post_reset can restore properly */ + } + mutex_unlock(&i2400m->init_mutex); + if (i2400m->bus_release) + i2400m->bus_release(i2400m); + d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result); + return result; +} +EXPORT_SYMBOL_GPL(i2400m_pre_reset); + + +/* + * Restore device state after a reset + * + * Do the work needed after a device reset to bring it up to the same + * state as it was before the reset. + * + * NOTE: this requires i2400m->init_mutex taken + */ +int i2400m_post_reset(struct i2400m *i2400m) +{ + int result = 0; + struct device *dev = i2400m_dev(i2400m); + + d_fnstart(3, dev, "(i2400m %p)\n", i2400m); + d_printf(1, dev, "post-reset start\n"); + if (i2400m->bus_setup) { + result = i2400m->bus_setup(i2400m); + if (result < 0) { + dev_err(dev, "bus-specific setup failed: %d\n", + result); + goto error_bus_setup; + } + } + mutex_lock(&i2400m->init_mutex); + if (i2400m->updown) { + result = __i2400m_dev_start( + i2400m, I2400M_BRI_SOFT | I2400M_BRI_MAC_REINIT); + if (result < 0) + goto error_dev_start; + } + mutex_unlock(&i2400m->init_mutex); + d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result); + return result; + +error_dev_start: + if (i2400m->bus_release) + i2400m->bus_release(i2400m); +error_bus_setup: + /* even if the device was up, it could not be recovered, so we + * mark it as down. */ + i2400m->updown = 0; + wmb(); /* see i2400m->updown's documentation */ + mutex_unlock(&i2400m->init_mutex); + d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result); + return result; +} +EXPORT_SYMBOL_GPL(i2400m_post_reset); + + /* * The device has rebooted; fix up the device and the driver * diff --git a/drivers/net/wimax/i2400m/i2400m.h b/drivers/net/wimax/i2400m/i2400m.h index 1724955e0fe9..8fc8a0ca5126 100644 --- a/drivers/net/wimax/i2400m/i2400m.h +++ b/drivers/net/wimax/i2400m/i2400m.h @@ -817,6 +817,8 @@ void i2400m_put(struct i2400m *i2400m) } extern int i2400m_dev_reset_handle(struct i2400m *, const char *); +extern int i2400m_pre_reset(struct i2400m *); +extern int i2400m_post_reset(struct i2400m *); /* * _setup()/_release() are called by the probe/disconnect functions of diff --git a/drivers/net/wimax/i2400m/usb.c b/drivers/net/wimax/i2400m/usb.c index 77567970fe9a..8b246cc498b1 100644 --- a/drivers/net/wimax/i2400m/usb.c +++ b/drivers/net/wimax/i2400m/usb.c @@ -637,6 +637,37 @@ int i2400mu_reset_resume(struct usb_interface *iface) } +/* + * Another driver or user space is triggering a reset on the device + * which contains the interface passed as an argument. Cease IO and + * save any device state you need to restore. + * + * If you need to allocate memory here, use GFP_NOIO or GFP_ATOMIC, if + * you are in atomic context. + */ +static +int i2400mu_pre_reset(struct usb_interface *iface) +{ + struct i2400mu *i2400mu = usb_get_intfdata(iface); + return i2400m_pre_reset(&i2400mu->i2400m); +} + + +/* + * The reset has completed. Restore any saved device state and begin + * using the device again. + * + * If you need to allocate memory here, use GFP_NOIO or GFP_ATOMIC, if + * you are in atomic context. + */ +static +int i2400mu_post_reset(struct usb_interface *iface) +{ + struct i2400mu *i2400mu = usb_get_intfdata(iface); + return i2400m_post_reset(&i2400mu->i2400m); +} + + static struct usb_device_id i2400mu_id_table[] = { { USB_DEVICE(0x8086, USB_DEVICE_ID_I6050) }, @@ -660,6 +691,8 @@ struct usb_driver i2400mu_driver = { .reset_resume = i2400mu_reset_resume, .probe = i2400mu_probe, .disconnect = i2400mu_disconnect, + .pre_reset = i2400mu_pre_reset, + .post_reset = i2400mu_post_reset, .id_table = i2400mu_id_table, .supports_autosuspend = 1, }; -- GitLab