diff options
author | Inaky Perez-Gonzalez <inaky@linux.intel.com> | 2009-10-07 07:34:13 +0400 |
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committer | Inaky Perez-Gonzalez <inaky@linux.intel.com> | 2009-10-19 10:56:18 +0400 |
commit | b9ee95010bee6c0e17d18bc9d9c0cfab6e8cb73a (patch) | |
tree | d1fd6706e054bb337d3ac79e96e32d2ec5145047 /drivers/net/wimax/i2400m/usb.c | |
parent | 5eeae35b9a2e304fc4ae3d9eed63afeea23b482c (diff) | |
download | linux-b9ee95010bee6c0e17d18bc9d9c0cfab6e8cb73a.tar.xz |
wimax/i2400m: fix deadlock: don't do BUS reset under i2400m->init_mutex
Since the addition of the pre/post reset handlers, it became clear
that we cannot do a I2400M-RT-BUS type reset while holding the
init_mutex, as in the case of USB, it will deadlock when trying to
call i2400m_pre_reset().
Thus, the following changes:
- clarify the fact that calling bus_reset() w/ I2400M_RT_BUS while
holding init_mutex is a no-no.
- i2400m_dev_reset_handle() will do a BUS reset to recover a gone
device after unlocking init_mutex.
- in the USB reset implementation, when cold and warm reset fails,
fallback to QUEUING a usb reset, not executing a USB reset, so it
happens from another context and does not deadlock.
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Diffstat (limited to 'drivers/net/wimax/i2400m/usb.c')
-rw-r--r-- | drivers/net/wimax/i2400m/usb.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/net/wimax/i2400m/usb.c b/drivers/net/wimax/i2400m/usb.c index 8b246cc498b1..418db12b0cd7 100644 --- a/drivers/net/wimax/i2400m/usb.c +++ b/drivers/net/wimax/i2400m/usb.c @@ -254,7 +254,6 @@ int i2400mu_bus_reset(struct i2400m *i2400m, enum i2400m_reset_type rt) sizeof(i2400m_COLD_BOOT_BARKER), i2400mu->endpoint_cfg.reset_cold); else if (rt == I2400M_RT_BUS) { -do_bus_reset: result = usb_reset_device(i2400mu->usb_dev); switch (result) { case 0: @@ -262,7 +261,7 @@ do_bus_reset: case -ENODEV: case -ENOENT: case -ESHUTDOWN: - result = rt == I2400M_RT_WARM ? -ENODEV : 0; + result = 0; break; /* We assume the device is disconnected */ default: dev_err(dev, "USB reset failed (%d), giving up!\n", @@ -275,10 +274,17 @@ do_bus_reset: if (result < 0 && result != -EINVAL /* device is gone */ && rt != I2400M_RT_BUS) { + /* + * Things failed -- resort to lower level reset, that + * we queue in another context; the reason for this is + * that the pre and post reset functionality requires + * the i2400m->init_mutex; RT_WARM and RT_COLD can + * come from areas where i2400m->init_mutex is taken. + */ dev_err(dev, "%s reset failed (%d); trying USB reset\n", rt == I2400M_RT_WARM ? "warm" : "cold", result); - rt = I2400M_RT_BUS; - goto do_bus_reset; + usb_queue_reset_device(i2400mu->usb_iface); + result = -ENODEV; } d_fnend(3, dev, "(i2400m %p rt %u) = %d\n", i2400m, rt, result); return result; |