linux/drivers/tty, branch v3.4.12

pch_uart: Add eg20t_port lock field, avoid recursive spinlocks

2012-10-02T17:30:37Z

commit 2588aba002d14e938c2f56d299ecf3e7ce1302a5 upstream. pch_uart_interrupt() takes priv->port.lock which leads to two recursive spinlock calls if low_latency==1 or CONFIG_PREEMPT_RT_FULL=y (one otherwise): pch_uart_interrupt spin_lock_irqsave(priv->port.lock, flags) case PCH_UART_IID_RDR_TO (data ready) handle_rx_to push_rx tty_port_tty_get spin_lock_irqsave(&port->lock, flags) <--- already hold this lock ... tty_flip_buffer_push ... flush_to_ldisc spin_lock_irqsave(&tty->buf.lock) spin_lock_irqsave(&tty->buf.lock) disc->ops->receive_buf(tty, char_buf) n_tty_receive_buf tty->ops->flush_chars() uart_flush_chars uart_start spin_lock_irqsave(&port->lock) <--- already hold this lock Avoid this by using a dedicated lock to protect the eg20t_port structure and IO access to its membase. This is more consistent with the 8250 driver. Ensure priv->lock is always take prior to priv->port.lock when taken at the same time. V2: Remove inadvertent whitespace change. V3: Account for oops_in_progress for the private lock in pch_console_write(). Note: Like the 8250 driver, if a printk is introduced anywhere inside the pch_console_write() critical section, the kernel will hang on a recursive spinlock on the private lock. The oops case is handled by using a trylock in the oops_in_progress case. Signed-off-by: Darren Hart CC: Tomoya MORINAGA CC: Feng Tang CC: Alexander Stein Acked-by: Alan Cox Signed-off-by: Greg Kroah-Hartman

pch_uart: Fix parity setting issue

2012-10-02T17:30:36Z

commit 38bd2a1ac736901d1cf4971c78ef952ba92ef78b upstream. Parity Setting value is reverse. E.G. In case of setting ODD parity, EVEN value is set. This patch inverts "if" condition. Signed-off-by: Tomoya MORINAGA Acked-by: Alan Cox Signed-off-by: Greg Kroah-Hartman

pch_uart: Fix rx error interrupt setting issue

2012-10-02T17:30:36Z

commit 9539dfb7ac1c84522fe1f79bb7dac2990f3de44a upstream. Rx Error interrupt(E.G. parity error) is not enabled. So, when parity error occurs, error interrupt is not occurred. As a result, the received data is not dropped. This patch adds enable/disable rx error interrupt code. Signed-off-by: Tomoya MORINAGA Acked-by: Alan Cox Signed-off-by: Greg Kroah-Hartman

pch_uart: Fix missing break for 16 byte fifo

2012-10-02T17:30:36Z

commit 9bc03743fff0770dc5a5324ba92e67cc377f16ca upstream. Otherwise we fall back to the wrong value. Reported-by: Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=44091 Signed-off-by: Alan Cox Signed-off-by: Tomoya MORINAGA Signed-off-by: Greg Kroah-Hartman

tty: serial: imx: console write routing is unsafe on SMP

2012-10-02T17:30:21Z

commit 9ec1882df244c4ee1baa692676fef5e8b0f5487d upstream. The console feature's write routing is unsafe on SMP with the startup/shutdown call. There could be several consumers of the console * the kernel printk * the init process using /dev/kmsg to call printk to show log * shell, which open /dev/console and write with sys_write() The shell goes into the normal uart open/write routing, but the other two go into the console operations. The open routing calls imx serial startup, which will write USR1/2 register without any lock and critical with imx_console_write call. Add a spin_lock for startup/shutdown/console_write routing. This patch is a port from Freescale's Android kernel. Signed-off-by: Xinyu Chen Tested-by: Dirk Behme CC: Sascha Hauer Acked-by: Shawn Guo Signed-off-by: Greg Kroah-Hartman

pmac_zilog,kdb: Fix console poll hook to return instead of loop

2012-08-26T22:00:43Z

commit 38f8eefccf3a23c4058a570fa2938a4f553cf8e0 upstream. kdb <-> kgdb transitioning does not work properly with this UART driver because the get character routine loops indefinitely as opposed to returning NO_POLL_CHAR per the expectation of the KDB I/O driver API. The symptom is a kernel hang when trying to switch debug modes. Signed-off-by: Jason Wessel Cc: Alan Cox Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

xen/hvc: Check HVM_PARAM_CONSOLE_[EVTCHN|PFN] for correctness.

2012-06-22T18:36:54Z

commit 5842f5768599094758931b74190cdf93641a8e35 upstream. We need to make sure that those parameters are setup to be correct. As such the value of 0 is deemed invalid and we find that we bail out. The hypervisor sets by default all of them to be zero and when the hypercall is done does a simple: a.value = d->arch.hvm_domain.params[a.index]; Which means that if the Xen toolstack forgot to setup the proper HVM_PARAM_CONSOLE_EVTCHN (or the PFN one), we would get the default value of 0 and use that. Fixes-Oracle-Bug: 14091238 Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Greg Kroah-Hartman

xen/hvc: Fix error cases around HVM_PARAM_CONSOLE_PFN

2012-06-22T18:36:53Z

commit a32c88b9386ce3df87f28dd46bdc3776cd6edf75 upstream. We weren't resetting the parameter to be passed in to a known default. Nor were we checking the return value of hvm_get_parameter. Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Greg Kroah-Hartman

xen/hvc: Collapse error logic.

2012-06-22T18:36:53Z

commit 2e5ad6b9c45d43cc4e7b8ac5ded1c55a7c4a3893 upstream. All of the error paths are doing the same logic. In which case we might as well collapse them in one path. Acked-by: Stefano Stabellini Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Greg Kroah-Hartman

hvc_xen: NULL dereference on allocation failure

2012-06-01T07:18:25Z

commit 201a52bea928687b7557728b176ac4f8a37d5cbd upstream. If kzalloc() returns a NULL here, we pass a NULL to xencons_disconnect_backend() which will cause an Oops. Also I removed the __GFP_ZERO while I was at it since kzalloc() implies __GFP_ZERO. Acked-by: Stefano Stabellini Signed-off-by: Dan Carpenter Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Greg Kroah-Hartman