linux-kernel - [PATCH] [POWERPC] cpm_uart: fix non-console port startup bug

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Message-ID: <49ADE738.2080108@windriver.com>
Date:	Wed, 04 Mar 2009 10:28:08 +0800
From:	Danny Feng <Xiaotian.Feng@...driver.com>
To:	galak@...nel.crashing.org, linuxppc-dev@...abs.org
CC:	linux-kernel@...r.kernel.org
Subject: [PATCH] [POWERPC] cpm_uart: fix non-console port startup bug

after UART interrupt handler is installed and rx is enabled, if an rx
interrupt comes before hardware init, rx->cur will be updated. Then the
hardware init will reset BD and make rx->cur out of sync, move the hardware
init code before request_irq.

Signed-off-by: Xiaotian Feng <xiaotian.feng@...driver.com>
---
diff --git a/drivers/serial/cpm_uart/cpm_uart_core.c
b/drivers/serial/cpm_uart/cpm_uart_core.c
index bde4b4b..5c6ef51 100644
--- a/drivers/serial/cpm_uart/cpm_uart_core.c
+++ b/drivers/serial/cpm_uart/cpm_uart_core.c
@@ -406,6 +406,18 @@ static int cpm_uart_startup(struct uart_port *port)

        pr_debug("CPM uart[%d]:startup\n", port->line);

+       /* If the port is not the console, make sure rx is disabled. */
+       if (!(pinfo->flags & FLAG_CONSOLE)) {
+               /* Disable UART rx */
+               if (IS_SMC(pinfo)) {
+                       clrbits16(&pinfo->smcp->smc_smcmr, SMCMR_REN);
+                       clrbits8(&pinfo->smcp->smc_smcm, SMCM_RX);
+               } else {
+                       clrbits32(&pinfo->sccp->scc_gsmrl, SCC_GSMRL_ENR);
+                       clrbits16(&pinfo->sccp->scc_sccm, UART_SCCM_RX);
+               }
+               cpm_line_cr_cmd(pinfo, CPM_CR_INIT_TRX);
+       }
        /* Install interrupt handler. */
        retval = request_irq(port->irq, cpm_uart_int, 0, "cpm_uart", port);
        if (retval)
@@ -420,8 +432,6 @@ static int cpm_uart_startup(struct uart_port *port)
                setbits32(&pinfo->sccp->scc_gsmrl, (SCC_GSMRL_ENR |
SCC_GSMRL_ENT));
        }

-       if (!(pinfo->flags & FLAG_CONSOLE))
-               cpm_line_cr_cmd(pinfo, CPM_CR_INIT_TRX);
        return 0;
 }



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