[PATCH] serial: Fix bug of ucc_uart

[PATCH] serial: Fix bug of ucc_uart

[Dave Liu]

Current ucc_uart driver doesn't work at UART mode,
The TxBD[READY] is not cleared by H/W (RISC engine)
when user send characters to Tx buffer of QE UART.
so, these characters stay on the QE forever, never
go to UART line.

The patch is fixing th bug.

Signed-off-by: Dave Liu <daveliu@freescale.com>
---
 drivers/serial/ucc_uart.c |   19 ++++++++++++++-----
 1 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/serial/ucc_uart.c b/drivers/serial/ucc_uart.c
index 7de66c0..e945e78 100644
--- a/drivers/serial/ucc_uart.c
+++ b/drivers/serial/ucc_uart.c
@@ -681,22 +681,27 @@ static void qe_uart_init_ucc(struct uart_qe_port *qe_port)
 	out_be16(&uccup->rccm, 0xc0ff);
 
 	/* Configure the GUMR registers for UART */
-	if (soft_uart)
+	if (soft_uart) {
 		/* Soft-UART requires a 1X multiplier for TX */
 		clrsetbits_be32(&uccp->gumr_l,
 			UCC_SLOW_GUMR_L_MODE_MASK | UCC_SLOW_GUMR_L_TDCR_MASK |
 			UCC_SLOW_GUMR_L_RDCR_MASK,
 			UCC_SLOW_GUMR_L_MODE_UART | UCC_SLOW_GUMR_L_TDCR_1 |
 			UCC_SLOW_GUMR_L_RDCR_16);
-	else
+
+		clrsetbits_be32(&uccp->gumr_h, UCC_SLOW_GUMR_H_RFW,
+			UCC_SLOW_GUMR_H_TRX | UCC_SLOW_GUMR_H_TTX);
+	} else {
 		clrsetbits_be32(&uccp->gumr_l,
 			UCC_SLOW_GUMR_L_MODE_MASK | UCC_SLOW_GUMR_L_TDCR_MASK |
 			UCC_SLOW_GUMR_L_RDCR_MASK,
 			UCC_SLOW_GUMR_L_MODE_UART | UCC_SLOW_GUMR_L_TDCR_16 |
 			UCC_SLOW_GUMR_L_RDCR_16);
 
-	clrsetbits_be32(&uccp->gumr_h, UCC_SLOW_GUMR_H_RFW,
-		UCC_SLOW_GUMR_H_TRX | UCC_SLOW_GUMR_H_TTX);
+		clrsetbits_be32(&uccp->gumr_h,
+			UCC_SLOW_GUMR_H_TRX | UCC_SLOW_GUMR_H_TTX,
+			UCC_SLOW_GUMR_H_RFW);
+	}
 
 #ifdef LOOPBACK
 	clrsetbits_be32(&uccp->gumr_l, UCC_SLOW_GUMR_L_DIAG_MASK,
@@ -706,7 +711,7 @@ static void qe_uart_init_ucc(struct uart_qe_port *qe_port)
 		UCC_SLOW_GUMR_H_CDS);
 #endif
 
-	/* Enable rx interrupts  and clear all pending events.  */
+	/* Disable rx interrupts  and clear all pending events.  */
 	out_be16(&uccp->uccm, 0);
 	out_be16(&uccp->ucce, 0xffff);
 	out_be16(&uccp->udsr, 0x7e7e);
@@ -765,6 +770,10 @@ static void qe_uart_init_ucc(struct uart_qe_port *qe_port)
 		cecr_subblock = ucc_slow_get_qe_cr_subblock(qe_port->ucc_num);
 		qe_issue_cmd(QE_INIT_TX_RX, cecr_subblock,
 			QE_CR_PROTOCOL_UNSPECIFIED, 0);
+	} else {
+		cecr_subblock = ucc_slow_get_qe_cr_subblock(qe_port->ucc_num);
+		qe_issue_cmd(QE_INIT_TX_RX, cecr_subblock,
+			QE_CR_PROTOCOL_UART, 0);
 	}
 }
 
-- 
1.5.4

Re: [PATCH] serial: Fix bug of ucc_uart

[Kumar Gala]

On Jun 8, 2009, at 9:24 AM, Dave Liu wrote:

> Current ucc_uart driver doesn't work at UART mode,
> The TxBD[READY] is not cleared by H/W (RISC engine)
> when user send characters to Tx buffer of QE UART.
> so, these characters stay on the QE forever, never
> go to UART line.
>
> The patch is fixing th bug.
>
> Signed-off-by: Dave Liu <daveliu@freescale.com>
> ---
> drivers/serial/ucc_uart.c |   19 ++++++++++++++-----
> 1 files changed, 14 insertions(+), 5 deletions(-)

applied to next.

(Cleaned up the commit message a bit)

- k