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@windriver.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 12 insertions, 2 deletions

diff --git a/drivers/serial/cpm_uart/cpm_uart_core.c b/drivers/serial/cpm_uart/cpm_uart_core.c
index bde4b4b0b80f..5c6ef51da274 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;
 }