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From: govindraj.raja@ti.com (Govindraj.R)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 05/12] OMAP: Serial: Hold console lock for console usage.
Date: Fri, 29 Apr 2011 18:09:49 +0530	[thread overview]
Message-ID: <1304080796-625-6-git-send-email-govindraj.raja@ti.com> (raw)
In-Reply-To: <1304080796-625-1-git-send-email-govindraj.raja@ti.com>

Acquire console lock before enabling and writing to console-uart
to avoid any recursive prints from console write.
for ex:
	--> printk
	  --> uart_console_write
	    --> get_sync
	      --> printk from omap_device enable
		--> uart_console write

Also during bootup console_lock is not available.
       --> uart_add_one_port
	   --> console_register
	       --> console_lock
	        --> console_unlock
	             --> call_console_drivers (here yet console_lock is not released)
		          --> uart_console_write

Hence convert prints from omap_device_enable/disable to pr_debug.

Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
---
 arch/arm/plat-omap/omap_device.c |    8 ++++----
 drivers/tty/serial/omap-serial.c |    8 +++++++-
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/arch/arm/plat-omap/omap_device.c b/arch/arm/plat-omap/omap_device.c
index 9bbda9a..f7c6dca 100644
--- a/arch/arm/plat-omap/omap_device.c
+++ b/arch/arm/plat-omap/omap_device.c
@@ -145,12 +145,12 @@ static int _omap_device_activate(struct omap_device *od, u8 ignore_lat)
 			odpl->activate_lat_worst = act_lat;
 			if (odpl->flags & OMAP_DEVICE_LATENCY_AUTO_ADJUST) {
 				odpl->activate_lat = act_lat;
-				pr_warning("omap_device: %s.%d: new worst case "
+				pr_debug("omap_device: %s.%d: new worst case "
 					   "activate latency %d: %llu\n",
 					   od->pdev.name, od->pdev.id,
 					   od->pm_lat_level, act_lat);
 			} else
-				pr_warning("omap_device: %s.%d: activate "
+				pr_debug("omap_device: %s.%d: activate "
 					   "latency %d higher than exptected. "
 					   "(%llu > %d)\n",
 					   od->pdev.name, od->pdev.id,
@@ -213,12 +213,12 @@ static int _omap_device_deactivate(struct omap_device *od, u8 ignore_lat)
 			odpl->deactivate_lat_worst = deact_lat;
 			if (odpl->flags & OMAP_DEVICE_LATENCY_AUTO_ADJUST) {
 				odpl->deactivate_lat = deact_lat;
-				pr_warning("omap_device: %s.%d: new worst case "
+				pr_debug("omap_device: %s.%d: new worst case "
 					   "deactivate latency %d: %llu\n",
 					   od->pdev.name, od->pdev.id,
 					   od->pm_lat_level, deact_lat);
 			} else
-				pr_warning("omap_device: %s.%d: deactivate "
+				pr_debug("omap_device: %s.%d: deactivate "
 					   "latency %d higher than exptected. "
 					   "(%llu > %d)\n",
 					   od->pdev.name, od->pdev.id,
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 633dfb4..7d8ca45 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1007,7 +1007,10 @@ serial_omap_console_write(struct console *co, const char *s,
 	struct uart_omap_port *up = serial_omap_console_ports[co->index];
 	unsigned long flags;
 	unsigned int ier;
-	int locked = 1;
+	int console_lock = 0, locked = 1;
+
+	if (console_trylock())
+		console_lock = 1;
 
 	local_irq_save(flags);
 	if (up->port.sysrq)
@@ -1043,6 +1046,9 @@ serial_omap_console_write(struct console *co, const char *s,
 	if (up->msr_saved_flags)
 		check_modem_status(up);
 
+	if (console_lock)
+		console_unlock();
+
 	serial_omap_port_disable(up);
 	if (locked)
 		spin_unlock(&up->port.lock);
-- 
1.7.1

  parent reply	other threads:[~2011-04-29 12:39 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-29 12:39 [PATCH v2 00/12] OMAP2+: Serial: Runtime adaptation + cleanup Govindraj.R
2011-04-29 12:39 ` [PATCH v2 01/12] OMAP2+: UART: Remove certain uart calls from sram_idle Govindraj.R
2011-04-29 12:39 ` [PATCH v2 02/12] OMAP2+: UART: Remove uart clock handling code from serial.c Govindraj.R
2011-04-29 13:20   ` Alan Cox
2011-04-29 12:39 ` [PATCH v2 03/12] OMAP2+: Serial: Add default mux for all uarts Govindraj.R
2011-05-04 10:00   ` Tony Lindgren
2011-05-04 10:34     ` Govindraj
2011-04-29 12:39 ` [PATCH v2 04/12] Serial: OMAP: Add runtime pm support for omap-serial driver Govindraj.R
2011-05-04 20:35   ` Kevin Hilman
2011-05-04 21:05     ` Paul Walmsley
2011-05-05  5:48     ` Raja, Govindraj
2011-05-05  5:55     ` Govindraj
2011-04-29 12:39 ` Govindraj.R [this message]
2011-05-04 10:02   ` [PATCH v2 05/12] OMAP: Serial: Hold console lock for console usage Tony Lindgren
2011-05-04 10:09     ` Russell King - ARM Linux
2011-05-04 10:19     ` Govindraj
2011-05-04 20:43   ` Kevin Hilman
2011-05-05 10:25     ` Govindraj
2011-05-05 14:52       ` Kevin Hilman
2011-04-29 12:39 ` [PATCH v2 06/12] Serial: OMAP2+: Move erratum handling from serial.c Govindraj.R
2011-04-29 12:39 ` [PATCH v2 07/12] OMAP: Serial: Allow UART parameters to be configured from board file Govindraj.R
2011-05-04  9:55   ` Tony Lindgren
2011-05-04 10:06     ` Govindraj
2011-05-04 10:25       ` Tony Lindgren
2011-05-04 10:39         ` Govindraj
2011-04-29 12:39 ` [PATCH v2 08/12] Serial: OMAP2+: Make the RX_TIMEOUT for DMA configurable for each UART Govindraj.R
2011-04-29 12:39 ` [PATCH v2 09/12] OMAP3: Serial: Remove uart pads from 3430 board file Govindraj.R
2011-04-29 12:39 ` [PATCH v2 10/12] OMAP2+: hwmod: Add api to enable io_ring wakeup Govindraj.R
2011-05-04 23:59   ` Kevin Hilman
2011-05-05  5:58     ` Govindraj
2011-04-29 12:39 ` [PATCH v2 11/12] OMAP: Serial: Use resume call from prcm to enable uart Govindraj.R
2011-05-05  0:11   ` Kevin Hilman
2011-05-05 11:46     ` Govindraj
2011-05-05 14:58       ` Kevin Hilman
2011-05-06  9:16         ` Govindraj
2011-05-06 15:55           ` Kevin Hilman
2011-05-09 12:23             ` Govindraj
2011-04-29 12:39 ` [PATCH v2 12/12] OMAP2: Serial: Add no async wake flag Govindraj.R
2011-05-05 17:32   ` Kevin Hilman
2011-05-06  9:34     ` Govindraj

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