linux/drivers/tty, branch v3.5.5

pch_uart: Add eg20t_port lock field, avoid recursive spinlocks

2012-10-02T17:39:49Z

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

2012-10-02T17:39:48Z

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

2012-10-02T17:39:48Z

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

2012-10-02T17:39:48Z

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: don't reinit clock in imx_setup_ufcr()

2012-10-02T17:39:39Z

commit 7be0670f7b9198382938a03ff3db7f47ef6b4780 upstream. Remove the clock configuration from imx_setup_ufcr(). This isn't needed here and will cause garbage output if done. To be be sure that we only touch the bits we want (TXTL and RXTL) we have to mask out all other bits of the UFCR register. Add one non-existing bit macro for this, too (bit 6, DCEDTE on i.MX6). Signed-off-by: Dirk Behme CC: Shawn Guo CC: Sascha Hauer CC: Troy Kisky CC: Xinyu Chen Acked-by: Shawn Guo Signed-off-by: Greg Kroah-Hartman

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

2012-10-02T17:39:39Z

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

2012-08-26T02:31:45Z

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

tty/hvc_opal: Fix debug function name

2012-07-10T09:16:25Z

udbg_init_debug_opal() should be udbg_init_debug_opal_raw() as the caller in arch/powerpc/kernel/udbg.c expects Signed-off-by: Benjamin Herrenschmidt

Merge tag 'tty-3.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2012-06-20T22:13:13Z

Pull serial driver fixes from Greg Kroah-Hartman: "Here are 3 patches resolving a boot regression (the mop500 fix), a build warning fix, and a kernel-doc fix. All tiny, but should go into the final 3.5 release. Signed-off-by: Greg Kroah-Hartman " * tag 'tty-3.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: serial/amba-pl011: move custom pin control to driver serial: fix serial_txx9.c build warning/typo serial: fix kernel-doc warnings in 8250.c

Merge tag 'stable/for-linus-3.5-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

2012-06-16T00:17:15Z

Pull five Xen bug-fixes from Konrad Rzeszutek Wilk: - When booting as PVHVM we would try to use PV console - but would not validate the parameters causing us to crash during restore b/c we re-use the wrong event channel. - When booting on machines with SR-IOV PCI bridge we didn't check for the bridge and tried to use it. - Under AMD machines would advertise the APERFMPERF resulting in needless amount of MSRs from the guest. - A global value (xen_released_pages) was not subtracted at bootup when pages were added back in. This resulted in the balloon worker having the wrong account of how many pages were truly released. - Fix dead-lock when xen-blkfront is run in the same domain as xen-blkback. * tag 'stable/for-linus-3.5-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen: mark local pages as FOREIGN in the m2p_override xen/setup: filter APERFMPERF cpuid feature out xen/balloon: Subtract from xen_released_pages the count that is populated. xen/pci: Check for PCI bridge before using it. xen/events: Add WARN_ON when quick lookup found invalid type. xen/hvc: Check HVM_PARAM_CONSOLE_[EVTCHN|PFN] for correctness. xen/hvc: Fix error cases around HVM_PARAM_CONSOLE_PFN xen/hvc: Collapse error logic.