* [PATCH V2] serial: imx: enable the clocks only when the uart is used
@ 2013-06-04 1:59 Huang Shijie
2013-06-08 6:01 ` Shawn Guo
0 siblings, 1 reply; 14+ messages in thread
From: Huang Shijie @ 2013-06-04 1:59 UTC (permalink / raw)
To: linux-arm-kernel
Current code opens the clocks when the uart driver is probed.
This will wastes some power if several uarts are enabled, but not really
used.
So close these clocks for uart, and enable the clocks only when
the uart is used.
Signed-off-by: Huang Shijie <b32955@freescale.com>
---
v1 --> v2:
check the return value of clk_prepare_enable().
---
drivers/tty/serial/imx.c | 17 ++++++++++++++---
1 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 72bc1db..7cc4810 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -699,6 +699,14 @@ static int imx_startup(struct uart_port *port)
int retval;
unsigned long flags, temp;
+ retval = clk_prepare_enable(sport->clk_per);
+ if (retval)
+ goto error_out1;
+
+ retval = clk_prepare_enable(sport->clk_ipg);
+ if (retval)
+ goto error_out1;
+
imx_setup_ufcr(sport, 0);
/* disable the DREN bit (Data Ready interrupt enable) before
@@ -884,6 +892,9 @@ static void imx_shutdown(struct uart_port *port)
writel(temp, sport->port.membase + UCR1);
spin_unlock_irqrestore(&sport->port.lock, flags);
+
+ clk_disable_unprepare(sport->clk_per);
+ clk_disable_unprepare(sport->clk_ipg);
}
static void
@@ -1557,6 +1568,9 @@ static int serial_imx_probe(struct platform_device *pdev)
goto deinit;
platform_set_drvdata(pdev, sport);
+ clk_disable_unprepare(sport->clk_per);
+ clk_disable_unprepare(sport->clk_ipg);
+
return 0;
deinit:
if (pdata && pdata->exit)
@@ -1578,9 +1592,6 @@ static int serial_imx_remove(struct platform_device *pdev)
uart_remove_one_port(&imx_reg, &sport->port);
- clk_disable_unprepare(sport->clk_per);
- clk_disable_unprepare(sport->clk_ipg);
-
if (pdata && pdata->exit)
pdata->exit(pdev);
--
1.7.1
^ permalink raw reply related [flat|nested] 14+ messages in thread
* [PATCH V2] serial: imx: enable the clocks only when the uart is used
2013-06-04 1:59 [PATCH V2] serial: imx: enable the clocks only when the uart is used Huang Shijie
@ 2013-06-08 6:01 ` Shawn Guo
2013-06-08 6:22 ` Huang Shijie
0 siblings, 1 reply; 14+ messages in thread
From: Shawn Guo @ 2013-06-08 6:01 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, Jun 04, 2013 at 09:59:33AM +0800, Huang Shijie wrote:
> Current code opens the clocks when the uart driver is probed.
> This will wastes some power if several uarts are enabled, but not really
> used.
>
> So close these clocks for uart, and enable the clocks only when
> the uart is used.
>
> Signed-off-by: Huang Shijie <b32955@freescale.com>
Running linux-next 20130607, I just found that the serial console stops
working due to this patch. I think the clocks need to be enabled for
console as well.
Shawn
> ---
> v1 --> v2:
> check the return value of clk_prepare_enable().
> ---
> drivers/tty/serial/imx.c | 17 ++++++++++++++---
> 1 files changed, 14 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> index 72bc1db..7cc4810 100644
> --- a/drivers/tty/serial/imx.c
> +++ b/drivers/tty/serial/imx.c
> @@ -699,6 +699,14 @@ static int imx_startup(struct uart_port *port)
> int retval;
> unsigned long flags, temp;
>
> + retval = clk_prepare_enable(sport->clk_per);
> + if (retval)
> + goto error_out1;
> +
> + retval = clk_prepare_enable(sport->clk_ipg);
> + if (retval)
> + goto error_out1;
> +
> imx_setup_ufcr(sport, 0);
>
> /* disable the DREN bit (Data Ready interrupt enable) before
> @@ -884,6 +892,9 @@ static void imx_shutdown(struct uart_port *port)
>
> writel(temp, sport->port.membase + UCR1);
> spin_unlock_irqrestore(&sport->port.lock, flags);
> +
> + clk_disable_unprepare(sport->clk_per);
> + clk_disable_unprepare(sport->clk_ipg);
> }
>
> static void
> @@ -1557,6 +1568,9 @@ static int serial_imx_probe(struct platform_device *pdev)
> goto deinit;
> platform_set_drvdata(pdev, sport);
>
> + clk_disable_unprepare(sport->clk_per);
> + clk_disable_unprepare(sport->clk_ipg);
> +
> return 0;
> deinit:
> if (pdata && pdata->exit)
> @@ -1578,9 +1592,6 @@ static int serial_imx_remove(struct platform_device *pdev)
>
> uart_remove_one_port(&imx_reg, &sport->port);
>
> - clk_disable_unprepare(sport->clk_per);
> - clk_disable_unprepare(sport->clk_ipg);
> -
> if (pdata && pdata->exit)
> pdata->exit(pdev);
>
> --
> 1.7.1
>
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH V2] serial: imx: enable the clocks only when the uart is used
2013-06-08 6:01 ` Shawn Guo
@ 2013-06-08 6:22 ` Huang Shijie
2013-06-08 6:23 ` Shawn Guo
2013-06-08 8:15 ` Russell King - ARM Linux
0 siblings, 2 replies; 14+ messages in thread
From: Huang Shijie @ 2013-06-08 6:22 UTC (permalink / raw)
To: linux-arm-kernel
? 2013?06?08? 14:01, Shawn Guo ??:
> Running linux-next 20130607, I just found that the serial console stops
> working due to this patch. I think the clocks need to be enabled for
> console as well.
could you tell me the board?
i tested on imx6q-sabreauto boards, the console is ok.
thanks
Huang Shijie
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH V2] serial: imx: enable the clocks only when the uart is used
2013-06-08 6:22 ` Huang Shijie
@ 2013-06-08 6:23 ` Shawn Guo
2013-06-08 8:04 ` [PATCH] serial: imx: enable the clocks for console Huang Shijie
2013-06-08 11:56 ` Re[2]: [PATCH V2] serial: imx: enable the clocks only when the uart is used Alexander Shiyan
2013-06-08 8:15 ` Russell King - ARM Linux
1 sibling, 2 replies; 14+ messages in thread
From: Shawn Guo @ 2013-06-08 6:23 UTC (permalink / raw)
To: linux-arm-kernel
On Sat, Jun 08, 2013 at 02:22:39PM +0800, Huang Shijie wrote:
> ? 2013?06?08? 14:01, Shawn Guo ??:
> >Running linux-next 20130607, I just found that the serial console stops
> >working due to this patch. I think the clocks need to be enabled for
> >console as well.
> could you tell me the board?
> i tested on imx6q-sabreauto boards, the console is ok.
imx6q-sabresd
Shawn
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH] serial: imx: enable the clocks for console
2013-06-08 6:23 ` Shawn Guo
@ 2013-06-08 8:04 ` Huang Shijie
2013-06-08 13:11 ` Fabio Estevam
2013-06-08 11:56 ` Re[2]: [PATCH V2] serial: imx: enable the clocks only when the uart is used Alexander Shiyan
1 sibling, 1 reply; 14+ messages in thread
From: Huang Shijie @ 2013-06-08 8:04 UTC (permalink / raw)
To: linux-arm-kernel
The console's clocks are disabled after the uart driver is probed.
It makes that we can see less log from the console now
(though we still can get all the log by the `dmesg`).
So enable the clocks for console, and we can see all the log again.
Signed-off-by: Huang Shijie <b32955@freescale.com>
---
drivers/tty/serial/imx.c | 21 ++++++++++++---------
1 files changed, 12 insertions(+), 9 deletions(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 7a761f7..b86587f 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -702,13 +702,14 @@ static int imx_startup(struct uart_port *port)
int retval;
unsigned long flags, temp;
- retval = clk_prepare_enable(sport->clk_per);
- if (retval)
- goto error_out1;
-
- retval = clk_prepare_enable(sport->clk_ipg);
- if (retval)
- goto error_out1;
+ if (!uart_console(port)) {
+ retval = clk_prepare_enable(sport->clk_per);
+ if (retval)
+ goto error_out1;
+ retval = clk_prepare_enable(sport->clk_ipg);
+ if (retval)
+ goto error_out1;
+ }
imx_setup_ufcr(sport, 0);
@@ -1578,8 +1579,10 @@ static int serial_imx_probe(struct platform_device *pdev)
goto deinit;
platform_set_drvdata(pdev, sport);
- clk_disable_unprepare(sport->clk_per);
- clk_disable_unprepare(sport->clk_ipg);
+ if (!uart_console(&sport->port)) {
+ clk_disable_unprepare(sport->clk_per);
+ clk_disable_unprepare(sport->clk_ipg);
+ }
return 0;
deinit:
--
1.7.1
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH] serial: imx: enable the clocks for console
2013-06-08 8:04 ` [PATCH] serial: imx: enable the clocks for console Huang Shijie
@ 2013-06-08 13:11 ` Fabio Estevam
2013-06-09 2:01 ` [PATCH v2] " Huang Shijie
2013-06-09 2:17 ` [PATCH] " Huang Shijie
0 siblings, 2 replies; 14+ messages in thread
From: Fabio Estevam @ 2013-06-08 13:11 UTC (permalink / raw)
To: linux-arm-kernel
Hi Huang,
On Sat, Jun 8, 2013 at 5:04 AM, Huang Shijie <b32955@freescale.com> wrote:
> + if (!uart_console(port)) {
> + retval = clk_prepare_enable(sport->clk_per);
> + if (retval)
> + goto error_out1;
> + retval = clk_prepare_enable(sport->clk_ipg);
> + if (retval)
> + goto error_out1;
Here you should not jump to "error_out1".
You should jump to a different label and disable the sport->clk_per clock.
This was also wrong in your previous patch.
^ permalink raw reply [flat|nested] 14+ messages in thread* [PATCH v2] serial: imx: enable the clocks for console
2013-06-08 13:11 ` Fabio Estevam
@ 2013-06-09 2:01 ` Huang Shijie
2013-06-09 8:34 ` Shawn Guo
2013-06-09 2:17 ` [PATCH] " Huang Shijie
1 sibling, 1 reply; 14+ messages in thread
From: Huang Shijie @ 2013-06-09 2:01 UTC (permalink / raw)
To: linux-arm-kernel
The console's clocks are disabled after the uart driver is probed.
It makes that we can see less log from the console now
(though we still can get all the log by the `dmesg`).
So enable the clocks for console, and we can see all the log again.
This patch also disables the sport->clk_per when we fail to enable
the sport->clk_ipg;
Signed-off-by: Huang Shijie <b32955@freescale.com>
---
v1 --> v2:
disable the sport->clk_per when we fail to enable
the sport->clk_ipg;
---
drivers/tty/serial/imx.c | 23 ++++++++++++++---------
1 files changed, 14 insertions(+), 9 deletions(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 7a761f7..78f8097 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -702,13 +702,16 @@ static int imx_startup(struct uart_port *port)
int retval;
unsigned long flags, temp;
- retval = clk_prepare_enable(sport->clk_per);
- if (retval)
- goto error_out1;
-
- retval = clk_prepare_enable(sport->clk_ipg);
- if (retval)
- goto error_out1;
+ if (!uart_console(port)) {
+ retval = clk_prepare_enable(sport->clk_per);
+ if (retval)
+ goto error_out1;
+ retval = clk_prepare_enable(sport->clk_ipg);
+ if (retval) {
+ clk_disable_unprepare(sport->clk_per);
+ goto error_out1;
+ }
+ }
imx_setup_ufcr(sport, 0);
@@ -1578,8 +1581,10 @@ static int serial_imx_probe(struct platform_device *pdev)
goto deinit;
platform_set_drvdata(pdev, sport);
- clk_disable_unprepare(sport->clk_per);
- clk_disable_unprepare(sport->clk_ipg);
+ if (!uart_console(&sport->port)) {
+ clk_disable_unprepare(sport->clk_per);
+ clk_disable_unprepare(sport->clk_ipg);
+ }
return 0;
deinit:
--
1.7.1
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v2] serial: imx: enable the clocks for console
2013-06-09 2:01 ` [PATCH v2] " Huang Shijie
@ 2013-06-09 8:34 ` Shawn Guo
2013-06-09 13:05 ` Shawn Guo
0 siblings, 1 reply; 14+ messages in thread
From: Shawn Guo @ 2013-06-09 8:34 UTC (permalink / raw)
To: linux-arm-kernel
On Sun, Jun 09, 2013 at 10:01:19AM +0800, Huang Shijie wrote:
> The console's clocks are disabled after the uart driver is probed.
> It makes that we can see less log from the console now
> (though we still can get all the log by the `dmesg`).
>
> So enable the clocks for console, and we can see all the log again.
>
> This patch also disables the sport->clk_per when we fail to enable
> the sport->clk_ipg;
>
> Signed-off-by: Huang Shijie <b32955@freescale.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v2] serial: imx: enable the clocks for console
2013-06-09 8:34 ` Shawn Guo
@ 2013-06-09 13:05 ` Shawn Guo
2013-06-09 17:26 ` Greg KH
0 siblings, 1 reply; 14+ messages in thread
From: Shawn Guo @ 2013-06-09 13:05 UTC (permalink / raw)
To: linux-arm-kernel
On Sun, Jun 09, 2013 at 04:34:11PM +0800, Shawn Guo wrote:
> On Sun, Jun 09, 2013 at 10:01:19AM +0800, Huang Shijie wrote:
> > The console's clocks are disabled after the uart driver is probed.
> > It makes that we can see less log from the console now
> > (though we still can get all the log by the `dmesg`).
> >
> > So enable the clocks for console, and we can see all the log again.
> >
> > This patch also disables the sport->clk_per when we fail to enable
> > the sport->clk_ipg;
> >
> > Signed-off-by: Huang Shijie <b32955@freescale.com>
>
> Tested-by: Shawn Guo <shawn.guo@linaro.org>
Sorry. I have to take that back.
Though it works fine with BusyBox, I'm getting the following warnings
when booting with an Ubuntu 13.04 rootfs, in which case imx_startup()
and imx_shutdown() will be called for a number of iterations. That
causes unbalanced clk_prepare_enable vs. clk_disable_unprepare, since
the clk_prepare_enable is under condition if (!uart_console(port)) in
imx_startup(), while clk_disable_unprepare in imx_shutdown() is not.
Shawn
------------[ cut here ]------------
WARNING: CPU: 0 PID: 70 at /home/r65073/repos/next/linux-next/drivers/clk/clk.c:780 __clk_disable+0x68/0x84()
Modules linked in:
CPU: 0 PID: 70 Comm: mountall Not tainted 3.10.0-rc4-next-20130607+ #435
Backtrace:
[<800116a4>] (dump_backtrace+0x0/0x10c) from [<80011844>] (show_stack+0x18/0x1c)
r6:8069f4e8 r5:0000030c r4:00000000 r3:00000000
[<8001182c>] (show_stack+0x0/0x1c) from [<8053bce0>] (dump_stack+0x78/0x94)
[<8053bc68>] (dump_stack+0x0/0x94) from [<80023df8>] (warn_slowpath_common+0x6c/0x8c)
r4:00000000 r3:00000000
[<80023d8c>] (warn_slowpath_common+0x0/0x8c) from [<80023e3c>] (warn_slowpath_null+0x24/0x2c)
r8:bf2ed008 r7:bfaa9810 r6:000f0013 r5:bf824b80 r4:bf824b80
[<80023e18>] (warn_slowpath_null+0x0/0x2c) from [<8041af84>] (__clk_disable+0x68/0x84)
[<8041af1c>] (__clk_disable+0x0/0x84) from [<8041b098>] (clk_disable+0x20/0x2c)
r4:600f0013 r3:00000001
[<8041b078>] (clk_disable+0x0/0x2c) from [<802c93e8>] (imx_shutdown+0xbc/0xec)
r5:bf824b80 r4:bfaa9810
[<802c932c>] (imx_shutdown+0x0/0xec) from [<802c63a0>] (uart_port_shutdown+0x34/0x40)
r5:bf86f860 r4:bfaa9810
[<802c636c>] (uart_port_shutdown+0x0/0x40) from [<802c68c0>] (uart_shutdown+0x98/0xc4)
r4:bf86f800 r3:00000000
[<802c6828>] (uart_shutdown+0x0/0xc4) from [<802c7514>] (uart_close+0x5c/0x198)
r7:bfaa9810 r6:bf274400 r5:bf86f86c r4:bf86f800
[<802c74b8>] (uart_close+0x0/0x198) from [<802ac648>] (tty_release+0xf8/0x500)
[<802ac550>] (tty_release+0x0/0x500) from [<800c5a30>] (__fput+0x9c/0x208)
[<800c5994>] (__fput+0x0/0x208) from [<800c5bac>] (____fput+0x10/0x14)
[<800c5b9c>] (____fput+0x0/0x14) from [<80040234>] (task_work_run+0xb4/0xec)
[<80040180>] (task_work_run+0x0/0xec) from [<80029238>] (do_exit+0x2b0/0x920)
r8:8000e144 r7:000000f8 r6:bf306300 r5:00000000 r4:bfac1180
[<80028f88>] (do_exit+0x0/0x920) from [<80029a4c>] (do_group_exit+0x50/0xd4)
r7:000000f8
[<800299fc>] (do_group_exit+0x0/0xd4) from [<80029ae8>] (__wake_up_parent+0x0/0x28)
r7:000000f8 r6:00000001 r5:0006f7ae r4:0006f79a
[<80029ad0>] (SyS_exit_group+0x0/0x18) from [<8000dfc0>] (ret_fast_syscall+0x0/0x30)
---[ end trace 16d080eb7efea4e9 ]---
------------[ cut here ]------------
WARNING: CPU: 0 PID: 70 at /home/r65073/repos/next/linux-next/drivers/clk/clk.c:689 __clk_unprepare+0x6c/0x8c()
Modules linked in:
CPU: 0 PID: 70 Comm: mountall Tainted: G W 3.10.0-rc4-next-20130607+ #435
Backtrace:
[<800116a4>] (dump_backtrace+0x0/0x10c) from [<80011844>] (show_stack+0x18/0x1c)
r6:8069f4e8 r5:000002b1 r4:00000000 r3:00000000
[<8001182c>] (show_stack+0x0/0x1c) from [<8053bce0>] (dump_stack+0x78/0x94)
[<8053bc68>] (dump_stack+0x0/0x94) from [<80023df8>] (warn_slowpath_common+0x6c/0x8c)
r4:00000000 r3:00000000
[<80023d8c>] (warn_slowpath_common+0x0/0x8c) from [<80023e3c>] (warn_slowpath_null+0x24/0x2c)
r8:bf2ed008 r7:bfaa9810 r6:000f0013 r5:bf824b80 r4:bf824b80
[<80023e18>] (warn_slowpath_null+0x0/0x2c) from [<8041b68c>] (__clk_unprepare+0x6c/0x8c)
[<8041b620>] (__clk_unprepare+0x0/0x8c) from [<8041b6c8>] (clk_unprepare+0x1c/0x24)
r4:bf824b80 r3:00000000
[<8041b6ac>] (clk_unprepare+0x0/0x24) from [<802c93f0>] (imx_shutdown+0xc4/0xec)
r4:bfaa9810 r3:00000000
[<802c932c>] (imx_shutdown+0x0/0xec) from [<802c63a0>] (uart_port_shutdown+0x34/0x40)
r5:bf86f860 r4:bfaa9810
[<802c636c>] (uart_port_shutdown+0x0/0x40) from [<802c68c0>] (uart_shutdown+0x98/0xc4)
r4:bf86f800 r3:00000000
[<802c6828>] (uart_shutdown+0x0/0xc4) from [<802c7514>] (uart_close+0x5c/0x198)
r7:bfaa9810 r6:bf274400 r5:bf86f86c r4:bf86f800
[<802c74b8>] (uart_close+0x0/0x198) from [<802ac648>] (tty_release+0xf8/0x500)
[<802ac550>] (tty_release+0x0/0x500) from [<800c5a30>] (__fput+0x9c/0x208)
[<800c5994>] (__fput+0x0/0x208) from [<800c5bac>] (____fput+0x10/0x14)
[<800c5b9c>] (____fput+0x0/0x14) from [<80040234>] (task_work_run+0xb4/0xec)
[<80040180>] (task_work_run+0x0/0xec) from [<80029238>] (do_exit+0x2b0/0x920)
r8:8000e144 r7:000000f8 r6:bf306300 r5:00000000 r4:bfac1180
[<80028f88>] (do_exit+0x0/0x920) from [<80029a4c>] (do_group_exit+0x50/0xd4)
r7:000000f8
[<800299fc>] (do_group_exit+0x0/0xd4) from [<80029ae8>] (__wake_up_parent+0x0/0x28)
r7:000000f8 r6:00000001 r5:0006f7ae r4:0006f79a
[<80029ad0>] (SyS_exit_group+0x0/0x18) from [<8000dfc0>] (ret_fast_syscall+0x0/0x30)
---[ end trace 16d080eb7efea4ea ]---
------------[ cut here ]------------
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v2] serial: imx: enable the clocks for console
2013-06-09 13:05 ` Shawn Guo
@ 2013-06-09 17:26 ` Greg KH
2013-06-10 0:55 ` Shawn Guo
0 siblings, 1 reply; 14+ messages in thread
From: Greg KH @ 2013-06-09 17:26 UTC (permalink / raw)
To: linux-arm-kernel
On Sun, Jun 09, 2013 at 09:05:47PM +0800, Shawn Guo wrote:
> On Sun, Jun 09, 2013 at 04:34:11PM +0800, Shawn Guo wrote:
> > On Sun, Jun 09, 2013 at 10:01:19AM +0800, Huang Shijie wrote:
> > > The console's clocks are disabled after the uart driver is probed.
> > > It makes that we can see less log from the console now
> > > (though we still can get all the log by the `dmesg`).
> > >
> > > So enable the clocks for console, and we can see all the log again.
> > >
> > > This patch also disables the sport->clk_per when we fail to enable
> > > the sport->clk_ipg;
> > >
> > > Signed-off-by: Huang Shijie <b32955@freescale.com>
> >
> > Tested-by: Shawn Guo <shawn.guo@linaro.org>
>
> Sorry. I have to take that back.
>
> Though it works fine with BusyBox, I'm getting the following warnings
> when booting with an Ubuntu 13.04 rootfs, in which case imx_startup()
> and imx_shutdown() will be called for a number of iterations. That
> causes unbalanced clk_prepare_enable vs. clk_disable_unprepare, since
> the clk_prepare_enable is under condition if (!uart_console(port)) in
> imx_startup(), while clk_disable_unprepare in imx_shutdown() is not.
I had just applied this to my tree, should I revert it because of this
problem?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v2] serial: imx: enable the clocks for console
2013-06-09 17:26 ` Greg KH
@ 2013-06-10 0:55 ` Shawn Guo
0 siblings, 0 replies; 14+ messages in thread
From: Shawn Guo @ 2013-06-10 0:55 UTC (permalink / raw)
To: linux-arm-kernel
On Sun, Jun 09, 2013 at 10:26:28AM -0700, Greg KH wrote:
> On Sun, Jun 09, 2013 at 09:05:47PM +0800, Shawn Guo wrote:
> > On Sun, Jun 09, 2013 at 04:34:11PM +0800, Shawn Guo wrote:
> > > On Sun, Jun 09, 2013 at 10:01:19AM +0800, Huang Shijie wrote:
> > > > The console's clocks are disabled after the uart driver is probed.
> > > > It makes that we can see less log from the console now
> > > > (though we still can get all the log by the `dmesg`).
> > > >
> > > > So enable the clocks for console, and we can see all the log again.
> > > >
> > > > This patch also disables the sport->clk_per when we fail to enable
> > > > the sport->clk_ipg;
> > > >
> > > > Signed-off-by: Huang Shijie <b32955@freescale.com>
> > >
> > > Tested-by: Shawn Guo <shawn.guo@linaro.org>
> >
> > Sorry. I have to take that back.
> >
> > Though it works fine with BusyBox, I'm getting the following warnings
> > when booting with an Ubuntu 13.04 rootfs, in which case imx_startup()
> > and imx_shutdown() will be called for a number of iterations. That
> > causes unbalanced clk_prepare_enable vs. clk_disable_unprepare, since
> > the clk_prepare_enable is under condition if (!uart_console(port)) in
> > imx_startup(), while clk_disable_unprepare in imx_shutdown() is not.
>
> I had just applied this to my tree, should I revert it because of this
> problem?
Fabio just sent an incremental fix "serial: imx: Fix serial clock
unbalance" for that.
Shawn
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH] serial: imx: enable the clocks for console
2013-06-08 13:11 ` Fabio Estevam
2013-06-09 2:01 ` [PATCH v2] " Huang Shijie
@ 2013-06-09 2:17 ` Huang Shijie
1 sibling, 0 replies; 14+ messages in thread
From: Huang Shijie @ 2013-06-09 2:17 UTC (permalink / raw)
To: linux-arm-kernel
? 2013?06?08? 21:11, Fabio Estevam ??:
> Hi Huang,
>
> On Sat, Jun 8, 2013 at 5:04 AM, Huang Shijie<b32955@freescale.com> wrote:
>
>> + if (!uart_console(port)) {
>> + retval = clk_prepare_enable(sport->clk_per);
>> + if (retval)
>> + goto error_out1;
>> + retval = clk_prepare_enable(sport->clk_ipg);
>> + if (retval)
>> + goto error_out1;
> Here you should not jump to "error_out1".
>
> You should jump to a different label and disable the sport->clk_per clock.
yes. you are right.
I will fix it in the patch "serial: imx: enable the clocks for console"
thanks
Huang Shijie
> This was also wrong in your previous patch.
>
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re[2]: [PATCH V2] serial: imx: enable the clocks only when the uart is used
2013-06-08 6:23 ` Shawn Guo
2013-06-08 8:04 ` [PATCH] serial: imx: enable the clocks for console Huang Shijie
@ 2013-06-08 11:56 ` Alexander Shiyan
1 sibling, 0 replies; 14+ messages in thread
From: Alexander Shiyan @ 2013-06-08 11:56 UTC (permalink / raw)
To: linux-arm-kernel
> On Sat, Jun 08, 2013 at 02:22:39PM +0800, Huang Shijie wrote:
> > ? 2013?06?08? 14:01, Shawn Guo ??:
> > >Running linux-next 20130607, I just found that the serial console stops
> > >working due to this patch. I think the clocks need to be enabled for
> > >console as well.
> > could you tell me the board?
> > i tested on imx6q-sabreauto boards, the console is ok.
>
> imx6q-sabresd
I confirm that console not work correct after this patch on the i.MX27 PCM038 board.
---
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH V2] serial: imx: enable the clocks only when the uart is used
2013-06-08 6:22 ` Huang Shijie
2013-06-08 6:23 ` Shawn Guo
@ 2013-06-08 8:15 ` Russell King - ARM Linux
1 sibling, 0 replies; 14+ messages in thread
From: Russell King - ARM Linux @ 2013-06-08 8:15 UTC (permalink / raw)
To: linux-arm-kernel
On Sat, Jun 08, 2013 at 02:22:39PM +0800, Huang Shijie wrote:
> ? 2013?06?08? 14:01, Shawn Guo ??:
>> Running linux-next 20130607, I just found that the serial console stops
>> working due to this patch. I think the clocks need to be enabled for
>> console as well.
> could you tell me the board?
> i tested on imx6q-sabreauto boards, the console is ok.
Take a look at amba-pl011.c to see how to deal with the console and clk API
correctly in serial drivers.
^ permalink raw reply [flat|nested] 14+ messages in thread
end of thread, other threads:[~2013-06-10 0:55 UTC | newest]
Thread overview: 14+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-06-04 1:59 [PATCH V2] serial: imx: enable the clocks only when the uart is used Huang Shijie
2013-06-08 6:01 ` Shawn Guo
2013-06-08 6:22 ` Huang Shijie
2013-06-08 6:23 ` Shawn Guo
2013-06-08 8:04 ` [PATCH] serial: imx: enable the clocks for console Huang Shijie
2013-06-08 13:11 ` Fabio Estevam
2013-06-09 2:01 ` [PATCH v2] " Huang Shijie
2013-06-09 8:34 ` Shawn Guo
2013-06-09 13:05 ` Shawn Guo
2013-06-09 17:26 ` Greg KH
2013-06-10 0:55 ` Shawn Guo
2013-06-09 2:17 ` [PATCH] " Huang Shijie
2013-06-08 11:56 ` Re[2]: [PATCH V2] serial: imx: enable the clocks only when the uart is used Alexander Shiyan
2013-06-08 8:15 ` Russell King - ARM Linux
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