Re: serial: start_tx & buffer handling

2018-05-03 Thread Muni Sekhar
On Fri, May 4, 2018 at 12:04 AM, Greg KH wrote: > On Thu, May 03, 2018 at 08:08:48PM +0530, Muni Sekhar wrote: >> Hi All, >> >> I’m trying to understand how user mode buffer is written to low level >> serial hardware registers. >> >> For this I read the kernel code and I came to

Re: serial: start_tx & buffer handling

2018-05-03 Thread Greg KH
On Thu, May 03, 2018 at 08:08:48PM +0530, Muni Sekhar wrote: > Hi All, > > I’m trying to understand how user mode buffer is written to low level > serial hardware registers. > > For this I read the kernel code and I came to know that from user mode > write() API lands into kernel’s tty_write()

serial: start_tx & buffer handling

2018-05-03 Thread Muni Sekhar
Hi All, I’m trying to understand how user mode buffer is written to low level serial hardware registers. For this I read the kernel code and I came to know that from user mode write() API lands into kernel’s tty_write() ("drivers/tty/tty_io.c") and then it calls a uart_write()

serial: custom baud rate

2018-05-03 Thread Muni Sekhar
Hi All, >From include/asm-generic/termbits.h , I see baudrate can be one of the standard values: 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 230400, 460800, 50, 576000, 921600, 100, 1152000, 150, 200, 250, 300, 350,