| Message ID | 1357558521-19365-1-git-send-email-javier.martinez@collabora.co.uk |
|---|---|
| State | Accepted |
| Delegated to: | Tom Rini |
| Headers | show |
On Mon, Jan 07, 2013 at 01:35:20AM -0000, Javier Martinez Canillas wrote: > Some platforms (e.g. IGEPv2 board) has a broken ns16550 UART that > does not set the TEMT bit when the transmitter is empty in SPL. > This makes U-Boot to hang while waiting for TEMT to be set. > > Add a new option to avoid this: > > CONFIG_SYS_NS16550_BROKEN_TEMT > > 16550 UART set the Transmitter Empty (TEMT) Bit when all output > has finished and the transmitter is totally empty. U-Boot waits > for this bit to be set to initialize the serial console. On some > broken platforms this bit is not set in SPL making U-Boot to > hang while waiting for TEMT. Define this option to avoid it. > > Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Applied to u-boot-ti/master, thanks!
diff --git a/README b/README index 78f40df..a89861e 100644 --- a/README +++ b/README @@ -616,6 +616,14 @@ The following options need to be configured: boot loader that has already initialized the UART. Define this variable to flush the UART at init time. + CONFIG_SYS_NS16550_BROKEN_TEMT + + 16550 UART set the Transmitter Empty (TEMT) Bit when all output + has finished and the transmitter is totally empty. U-Boot waits + for this bit to be set to initialize the serial console. On some + broken platforms this bit is not set in SPL making U-Boot to + hang while waiting for TEMT. Define this option to avoid it. + - Console Interface: Depending on board, define exactly one serial port diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c index bbd91ca..87a0917 100644 --- a/drivers/serial/ns16550.c +++ b/drivers/serial/ns16550.c @@ -36,8 +36,10 @@ void NS16550_init(NS16550_t com_port, int baud_divisor) { +#if (!defined(CONFIG_SYS_NS16550_BROKEN_TEMT)) while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT)) ; +#endif serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier); #if (defined(CONFIG_OMAP) && !defined(CONFIG_OMAP3_ZOOM2)) || \
Some platforms (e.g. IGEPv2 board) has a broken ns16550 UART that does not set the TEMT bit when the transmitter is empty in SPL. This makes U-Boot to hang while waiting for TEMT to be set. Add a new option to avoid this: CONFIG_SYS_NS16550_BROKEN_TEMT 16550 UART set the Transmitter Empty (TEMT) Bit when all output has finished and the transmitter is totally empty. U-Boot waits for this bit to be set to initialize the serial console. On some broken platforms this bit is not set in SPL making U-Boot to hang while waiting for TEMT. Define this option to avoid it. Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> --- README | 8 ++++++++ drivers/serial/ns16550.c | 2 ++ 2 files changed, 10 insertions(+), 0 deletions(-)