diff mbox

ARM: tegra: turn on UART A clock at boot

Message ID 1343170200-28228-1-git-send-email-swarren@wwwdotorg.org (mailing list archive)
State New, archived
Headers show

Commit Message

Stephen Warren July 24, 2012, 10:50 p.m. UTC 
From: Stephen Warren <swarren@nvidia.com>

Some boards use UART D for the main serial console, and some use UART A.
UART D's clock is listed in board-dt-tegra20.c's clock table, whereas
UART A's clock is not. This causes the clock code to think UART A's
clock is unsed. The common clock framework turns off unused clocks at
boot time. This makes the kernel appear to hang. Add UART A's clock into
the clock table to prevent this. Eventually, this requirement should be
handled by the UART driver, and/or properties in a board-specific device
tree file.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
 arch/arm/mach-tegra/board-dt-tegra20.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

Comments

Prashant Gaikwad July 25, 2012, 6:41 a.m. UTC | #1 
On Wednesday 25 July 2012 04:20 AM, Stephen Warren wrote:
> From: Stephen Warren<swarren@nvidia.com>
>
> Some boards use UART D for the main serial console, and some use UART A.
> UART D's clock is listed in board-dt-tegra20.c's clock table, whereas
> UART A's clock is not. This causes the clock code to think UART A's
> clock is unsed. The common clock framework turns off unused clocks at
> boot time. This makes the kernel appear to hang. Add UART A's clock into
> the clock table to prevent this. Eventually, this requirement should be
> handled by the UART driver, and/or properties in a board-specific device
> tree file.
>
> Signed-off-by: Stephen Warren<swarren@nvidia.com>

Thanks Stephen!!

Verified on Cardhu and Ventana with Common clock framework patches.

> ---
>   arch/arm/mach-tegra/board-dt-tegra20.c |    1 +
>   1 files changed, 1 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/mach-tegra/board-dt-tegra20.c b/arch/arm/mach-tegra/board-dt-tegra20.c
> index 70a19a9..5daffd5 100644
> --- a/arch/arm/mach-tegra/board-dt-tegra20.c
> +++ b/arch/arm/mach-tegra/board-dt-tegra20.c
> @@ -71,6 +71,7 @@ struct of_dev_auxdata tegra20_auxdata_lookup[] __initdata = {
>
>   static __initdata struct tegra_clk_init_table tegra_dt_clk_init_table[] = {
>   	/* name		parent		rate		enabled */
> +	{ "uarta",	"pll_p",	216000000,	true },
>   	{ "uartd",	"pll_p",	216000000,	true },
>   	{ "usbd",	"clk_m",	12000000,	false },
>   	{ "usb2",	"clk_m",	12000000,	false },
Stephen Warren Aug. 3, 2012, 6:01 p.m. UTC | #2 
On 07/24/2012 04:50 PM, Stephen Warren wrote:
> From: Stephen Warren <swarren@nvidia.com>
> 
> Some boards use UART D for the main serial console, and some use UART A.
> UART D's clock is listed in board-dt-tegra20.c's clock table, whereas
> UART A's clock is not. This causes the clock code to think UART A's
> clock is unsed. The common clock framework turns off unused clocks at
> boot time. This makes the kernel appear to hang. Add UART A's clock into
> the clock table to prevent this. Eventually, this requirement should be
> handled by the UART driver, and/or properties in a board-specific device
> tree file.

Applied to for-3.7/common-clk.
diff mbox

Patch

diff --git a/arch/arm/mach-tegra/board-dt-tegra20.c b/arch/arm/mach-tegra/board-dt-tegra20.c
index 70a19a9..5daffd5 100644
--- a/arch/arm/mach-tegra/board-dt-tegra20.c
+++ b/arch/arm/mach-tegra/board-dt-tegra20.c
@@ -71,6 +71,7 @@  struct of_dev_auxdata tegra20_auxdata_lookup[] __initdata = {
 
 static __initdata struct tegra_clk_init_table tegra_dt_clk_init_table[] = {
 	/* name		parent		rate		enabled */
+	{ "uarta",	"pll_p",	216000000,	true },
 	{ "uartd",	"pll_p",	216000000,	true },
 	{ "usbd",	"clk_m",	12000000,	false },
 	{ "usb2",	"clk_m",	12000000,	false },