#include #include pthread_mutex_t a = PTHREAD_MUTEX_INITIALIZER; pthread_mutex_t b = PTHREAD_MUTEX_INITIALIZER; pthread_barrier_t bar; void *ba_lock(void *arg) { int ret, i; pthread_mutex_lock(&b); if (pthread_barrier_wait(&bar) == PTHREAD_BARRIER_SERIAL_THREAD) pthread_barrier_destroy(&bar); pthread_mutex_lock(&a); pthread_mutex_unlock(&a); pthread_mutex_unlock(&b); } int main(void) { pthread_t t; pthread_barrier_init(&bar, NULL, 2); if (pthread_create(&t, NULL, ba_lock, NULL)) { fprintf(stderr, "pthread_create() failed\n"); return 1; } pthread_mutex_lock(&a); if (pthread_barrier_wait(&bar) == PTHREAD_BARRIER_SERIAL_THREAD) pthread_barrier_destroy(&bar); pthread_mutex_lock(&b); pthread_mutex_unlock(&b); pthread_mutex_unlock(&a); pthread_join(t, NULL); return 0; } -next.git
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authorThierry Reding <treding@nvidia.com>2016-05-26 17:23:29 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-06-07 22:15:25 -0700
commitf8a15a9650694feaa0dabf197b0c94d37cd3fb42 (patch)
tree270fc9e383c8fb0a9bc90a5833eb63e87e5d4efd
parentdcb21ad4385731b7fc3ef39d255685f2f63c8c5d (diff)
usb: host: ehci-tegra: Grab the correct UTMI pads reset
There are three EHCI controllers on Tegra SoCs, each with its own reset line. However, the first controller contains a set of UTMI configuration registers that are shared with its siblings. These registers will only be reset as part of the first controller's reset. For proper operation it must be ensured that the UTMI configuration registers are reset before any of the EHCI controllers are enabled, irrespective of the probe order. Commit a47cc24cd1e5 ("USB: EHCI: tegra: Fix probe order issue leading to broken USB") introduced code that ensures the first controller is always reset before setting up any of the controllers, and is never again reset afterwards. This code, however, grabs the wrong reset. Each EHCI controller has two reset controls attached: 1) the USB controller reset and 2) the UTMI pads reset (really the first controller's reset). In order to reset the UTMI pads registers the code must grab the second reset, but instead it grabbing the first. Fixes: a47cc24cd1e5 ("USB: EHCI: tegra: Fix probe order issue leading to broken USB") Acked-by: Jon Hunter <jonathanh@nvidia.com> Cc: stable@vger.kernel.org Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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