linux/drivers/tty/serial, branch v4.0

tty: serial: fsl_lpuart: clear receive flag on FIFO flush

2015-03-26T22:13:14Z

When the receiver was enabled during startup, a character could have been in the FIFO when the UART get initially used. The driver configures the (receive) watermark level, and flushes the FIFO. However, the receive flag (RDRF) could still be set at that stage (as mentioned in the register description of UARTx_RWFIFO). This leads to an interrupt which won't be handled properly in interrupt mode: The receive interrupt function lpuart_rxint checks the FIFO count, which is 0 at that point (due to the flush during initialization). The problem does not manifest when using DMA to receive characters. Fix this situation by explicitly read the status register, which leads to clearing of the RDRF flag. Due to the flush just after the status flag read, a explicit data read is not to required. Signed-off-by: Stefan Agner Cc: stable Signed-off-by: Greg Kroah-Hartman

tty: serial: fsl_lpuart: specify transmit FIFO size

2015-03-26T22:13:14Z

Specify transmit FIFO size which might be different depending on LPUART instance. This makes sure uart_wait_until_sent in serial core getting called, which in turn waits and checks if the FIFO is really empty on shutdown by using the tx_empty callback. Without the call of this callback, the last several characters might not yet be transmitted when closing the serial port. This can be reproduced by simply using echo and redirect the output to a ttyLP device. Signed-off-by: Stefan Agner Cc: stable Signed-off-by: Greg Kroah-Hartman

serial: samsung: Clear operation mode on UART shutdown

2015-03-26T22:13:14Z

Exynos serial ports operate either in a DMA-based or interrupt-based modes. In DMA-based mode, the UART generates a transfer data request and a Transmission (Tx) interrupt in interrupt-based mode. The Tx IRQ is only unmasked in interrupt-based mode and it was done in s3c24xx_serial_start_tx(). Commit ba019a3e2ad5 ("serial: samsung: remove redundant interrupt enabling") removed the IRQ enable on that function since it is enabled when the mode is set in enable_tx_pio(). The problem is that enable_tx_pio() is only called if the port mode has not been set before but the mode was not cleared on .shutdown(). So if the UART was shutdown and then started up again, the mode set will remain and the Tx IRQ won't be unmasked. This caused a hang on at least Exynos5250, Exynos5420 and Exynos5800 when the system is rebooted or powered off. Fixes: ba019a3e2ad5 ("serial: samsung: remove redundant interrupt enabling") Signed-off-by: Javier Martinez Canillas Reviewed-by: Sylwester Nawrocki Signed-off-by: Greg Kroah-Hartman

serial: 8250_dw: Fix deadlock in LCR workaround

2015-03-11T15:39:52Z

Trying to write console output from within the serial console driver while the port->lock is held causes recursive deadlock: CPU 0 spin_lock_irqsave(&port->lock) printk() console_unlock() call_console_drivers() serial8250_console_write() spin_lock_irqsave(&port->lock) ** DEADLOCK ** The 8250_dw i/o accessors try to write a console error message if the LCR workaround was unsuccessful. When the port->lock is already held (eg., when called from serial8250_set_termios()), this deadlocks. Make the error message a FIXME until a general solution is devised. Cc: Tim Kryger Reported-by: Zhang Zhen Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

Merge tag 'tty-4.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2015-03-08T19:25:40Z

Pull tty/serial fixes from Greg KH: "Here are some tty and serial driver fixes for 4.0-rc3. Along with the atime fix that you know about, here are some other serial driver bugfixes as well. Most notable is a wait_until_sent bugfix that was traced back to being around since before 2.6.12 that Johan has fixed up. All have been in linux-next successfully" * tag 'tty-4.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: TTY: fix tty_wait_until_sent maximum timeout TTY: fix tty_wait_until_sent on 64-bit machines USB: serial: fix infinite wait_until_sent timeout TTY: bfin_jtag_comm: remove incorrect wait_until_sent operation net: irda: fix wait_until_sent poll timeout serial: uapi: Declare all userspace-visible io types serial: core: Fix iotype userspace breakage serial: sprd: Fix missing spin_unlock in sprd_handle_irq() console: Fix console name size mismatch tty: fix up atime/mtime mess, take four serial: 8250_dw: Fix get_mctrl behaviour serial:8250:8250_pci: delete unneeded quirk entries serial:8250:8250_pci: fix redundant entry report for WCH_CH352_2S Change email address for 8250_pci serial: 8250: Revert "tty: serial: 8250_core: read only RX if there is something in the FIFO" Revert "tty/serial: of_serial: add DT alias ID handling"

serial: sprd: Fix missing spin_unlock in sprd_handle_irq()

2015-03-07T02:39:55Z

Fix return from sprd_handle_irq() with spin_lock held. Signed-off-by: Axel Lin Reviewed-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

serial: 8250_dw: Fix get_mctrl behaviour

2015-03-07T02:06:51Z

Fixed behaviour of get_mctrl() serial driver function as documented in: https://www.kernel.org/doc/Documentation/serial/driver Added device-tree properties 'dcd-override', 'dsr-override', 'cts-override', and 'ri-override' specific to the Synopsis 8250 DesignWare UART driver. Allows one to force Data Carrier Detect, Clear To Send, and Data Set Ready signals to permanently be reported as active. The Ring indicator can be forced to be reported as inactive. It is possible that if modem control signalling is enabled on a port that doesn't have these pins (e.g. - a simple two wire Tx/Rx port), the driver can hang indefinitely waiting for the state to change. The new DT properties allow the driver to ignore the state of these pins on serial ports that don't support them, as recommended in the kernel documentation. Reviewed-by: JD (Jiandong) Zheng Signed-off-by: Jonathan Richardson Signed-off-by: Greg Kroah-Hartman

serial:8250:8250_pci: delete unneeded quirk entries

2015-03-07T02:06:51Z

These quirk entries have the same effect as default quirk entry, so we can just delete them. Signed-off-by: Wang YanQing Signed-off-by: Greg Kroah-Hartman

serial:8250:8250_pci: fix redundant entry report for WCH_CH352_2S

2015-03-07T02:06:51Z

Commit 8b5c913f7ee6464849570bacb6bcd9ef0eaf7dce ("serial: 8250_pci: Add WCH CH352 quirk to avoid Xscale detection") trigger one redundant entry report message. This patch fix it. Reported-by: Russell King Signed-off-by: Wang YanQing Signed-off-by: Greg Kroah-Hartman

Change email address for 8250_pci

2015-03-07T02:06:51Z

I'm still receiving reports to my email address, so let's point this at the linux-serial mailing list instead. Cc: Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman