On Fri, Mar 28, 2008 at 04:58:37PM +0530, Tiju wrote:

Hi all

I am trying to port u-boot to a s3c2440 samsung processor.

I applied the smdk2440 boards patch (almost similar architecture) and trying to modify it for our board's requirement. But during the serial_init it goes to the _serial_putc and then after certain loops it goes to the hang function and hangs there.

this sounds like a flow control issue. The s3c24xx boards support hardware flow control handling, i.e. their TX FIFO will not transmit any more characters unless the RTS/CTS handshake allows it to.

Since the u-boot serial code does an endless loop waiting for the next character, it will busy-wait there.

Please note that this is true even for UARTs that don't even have RTS/CTS. Don't use hw flow control on them.

Another possible cause could be lack of proper GPIO configuration for the RTS/CTS pins, missing connection on the board, broken serial cable.

Basically anthing that affects RTS/CTS from within the s3c24xx and the PC on the other side.