summaryrefslogtreecommitdiff
path: root/drivers/tty/serial/8250/8250_early.c
AgeCommit message (Collapse)Author
2013-08-12serial: 8250_early: fix comparison of different typesJingoo Han
Fix the following sparse warning: drivers/tty/serial/8250/8250_early.c:196:26: error: incompatible types in comparison expression (different type sizes) Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-24tty/8250_early: Don't truncate last character of optionsHenrik Nordström
The earlier change to use strlcpy uncovered a bug in the options argument length calculation causing last character to be truncated. This makes the actual console to be configured with incorrect baudrate when specifying the console using console=uart,... syntax. Bug symptom seen in kernel log output: Kernel command line: console=uart,mmio,0x90000000,115200 Early serial console at MMIO 0x90000000 (options '11520') which then results in a invalid baud rate 11520 instead of the expected 115200 when the console is switched to ttyS0 later in the boot process. Signed-off-by: Henrik Nordstrom <henrik@henriknordstrom.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-20drivers/tty/serial/8250: use strlcpy instead of strcpyChen Gang
The fields must be null-terminated, or next printk for %s, will cause issue. Signed-off-by: Chen Gang <gang.chen@asianux.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-16tty/8250_early: Turn serial_in/serial_out into weak symbols.Noam Camus
Allows overriding default methods serial_in/serial_out. In such platform specific replacement it is possible to use other regshift, biased register offset, any other manipulation that is not covered with common default methods. Overriding default methods may be useful for platforms which got serial peripheral with registers represented in big endian. In this situation and assuming that 32 bit operations / alignment is required then it may be useful to swab words before/after accessing the serial registers. Signed-off-by: Noam Camus <noamc@ezchip.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-24serial/8250/8250_early: Prevent rounding error in uartclkAlexey Brodkin
Modify divisor to select the nearest baud rate divider rather than the lowest. It minimizes baud rate errors especially on low UART clock frequencies. For example, if uartclk is 33000000 and baud is 115200 the ratio is about 17.9 The current code selects 17 (5% error) but should select 18 (0.5% error). This 5% error in baud rate leads to garbage on receiving end, while 0.5% doesn't. The issue showed up when using the stock 8250 driver for Synopsys DW UART. This was on a FPGA with ~12MHz UART clock. When we enabled early serial, we saw garbage which was narrowed down to the rounding error. So the bug had been latent and it only showed up with such low clock rates. Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-01-24serial: group all the 8250 related code togetherPaul Gortmaker
The drivers/tty/serial dir is already getting rather busy. Relocate the 8250 related drivers to their own subdir to reduce the clutter. Note that sunsu.c is not included in this move -- it is 8250-like hardware, but it does not use any of the existing infrastructure -- and does not depend on SERIAL_8250. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>