From mboxrd@z Thu Jan 1 00:00:00 1970 From: Magnus Damm Date: Tue, 24 Feb 2009 06:57:12 +0000 Subject: [PATCH] sh-sci: console drainage Message-Id: <20090224065712.31491.72199.sendpatchset@rx1.opensource.se> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sh@vger.kernel.org From: Magnus Damm Modify the serial console code to wait for the transmit FIFO, make sure all bits have been put on the wire before returning. Signed-off-by: Magnus Damm --- This is the first step against clock framework integration, after all bits are sent we can disable the data clock. Also useful when debugging or shutting down a system. Tested with SCIF on sh7785lcr, not sure about SCI and SCIFA. drivers/serial/sh-sci.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- 0001/drivers/serial/sh-sci.c +++ work/drivers/serial/sh-sci.c 2009-02-18 15:59:05.000000000 +0900 @@ -139,7 +139,7 @@ static void sci_poll_put_char(struct uar } while (!(status & SCxSR_TDxE(port))); sci_in(port, SCxSR); /* Dummy read */ - sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port)); + sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port)); sci_out(port, SCxTDR, c); } #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE */ @@ -1095,6 +1095,7 @@ static void serial_console_write(struct unsigned count) { struct uart_port *port = &serial_console_port->port; + unsigned short bits; int i; for (i = 0; i < count; i++) { @@ -1103,6 +1104,11 @@ static void serial_console_write(struct sci_poll_put_char(port, *s++); } + + /* wait until fifo is empty and last bit has been transmitted */ + bits = SCxSR_TDxE(port) | SCxSR_TEND(port); + while ((sci_in(port, SCxSR) & bits) != bits) + cpu_relax(); } static int __init serial_console_setup(struct console *co, char *options)