[PATCH] clk: tegra: Don't reset PLL-CX if it is already enabled

[PATCH] clk: tegra: Don't reset PLL-CX if it is already enabled

[Jon Hunter]

Commit 8dce89a1c2cf ("clk: tegra: Don't warn for PLL defaults unnecessarily")
changed the tegra210_pllcx_set_defaults() function causing the PLL to
always be reset regardless of whether it is in-use. This function was
changed so that resetting of the PLL will only be skipped if the PLL
is enabled AND 'pllcx->params->defaults_set' is not true. However, the
'pllcx->params->defaults_set' is always true and hence, the PLL is now
always reset. This causes the boot to fail on the Tegra210 Smaug where
the PLL is already enabled and in-use. Fix this by only resetting the
PLL if not in-use and only printing the warning that the defaults are
not set after we have checked the default settings.

Fixes: 8dce89a1c2cf ("clk: tegra: Don't warn for PLL defaults unnecessarily")

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
---
 drivers/clk/tegra/clk-tegra210.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/clk/tegra/clk-tegra210.c b/drivers/clk/tegra/clk-tegra210.c
index 9897dc55676b..b56a104328fa 100644
--- a/drivers/clk/tegra/clk-tegra210.c
+++ b/drivers/clk/tegra/clk-tegra210.c
@@ -555,12 +555,12 @@ static void tegra210_pllcx_set_defaults(const char *name,
 {
 	pllcx->params->defaults_set = true;
 
-	if (readl_relaxed(clk_base + pllcx->params->base_reg) &
-			PLL_ENABLE && !pllcx->params->defaults_set) {
+	if (readl_relaxed(clk_base + pllcx->params->base_reg) & PLL_ENABLE) {
 		/* PLL is ON: only check if defaults already set */
 		pllcx_check_defaults(pllcx->params);
-		pr_warn("%s already enabled. Postponing set full defaults\n",
-			name);
+		if (!pllcx->params->defaults_set)
+			pr_warn("%s already enabled. Postponing set full defaults\n",
+				name);
 		return;
 	}
 
-- 
2.7.4

Re: [PATCH] clk: tegra: Don't reset PLL-CX if it is already enabled

[Peter De Schrijver]

Acked-By: Peter De Schrijver <pdeschrijver@nvidia.com>

On Mon, Mar 27, 2017 at 12:01:05PM +0100, Jon Hunter wrote:
> Commit 8dce89a1c2cf ("clk: tegra: Don't warn for PLL defaults unnecessarily")
> changed the tegra210_pllcx_set_defaults() function causing the PLL to
> always be reset regardless of whether it is in-use. This function was
> changed so that resetting of the PLL will only be skipped if the PLL
> is enabled AND 'pllcx->params->defaults_set' is not true. However, the
> 'pllcx->params->defaults_set' is always true and hence, the PLL is now
> always reset. This causes the boot to fail on the Tegra210 Smaug where
> the PLL is already enabled and in-use. Fix this by only resetting the
> PLL if not in-use and only printing the warning that the defaults are
> not set after we have checked the default settings.
> 
> Fixes: 8dce89a1c2cf ("clk: tegra: Don't warn for PLL defaults unnecessarily")
> 
> Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
> ---
>  drivers/clk/tegra/clk-tegra210.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/clk/tegra/clk-tegra210.c b/drivers/clk/tegra/clk-tegra210.c
> index 9897dc55676b..b56a104328fa 100644
> --- a/drivers/clk/tegra/clk-tegra210.c
> +++ b/drivers/clk/tegra/clk-tegra210.c
> @@ -555,12 +555,12 @@ static void tegra210_pllcx_set_defaults(const char *name,
>  {
>  	pllcx->params->defaults_set = true;
>  
> -	if (readl_relaxed(clk_base + pllcx->params->base_reg) &
> -			PLL_ENABLE && !pllcx->params->defaults_set) {
> +	if (readl_relaxed(clk_base + pllcx->params->base_reg) & PLL_ENABLE) {
>  		/* PLL is ON: only check if defaults already set */
>  		pllcx_check_defaults(pllcx->params);
> -		pr_warn("%s already enabled. Postponing set full defaults\n",
> -			name);
> +		if (!pllcx->params->defaults_set)
> +			pr_warn("%s already enabled. Postponing set full defaults\n",
> +				name);
>  		return;
>  	}
>  
> -- 
> 2.7.4
> 

Re: [PATCH] clk: tegra: Don't reset PLL-CX if it is already enabled

[Thierry Reding]

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On Mon, Mar 27, 2017 at 12:01:05PM +0100, Jon Hunter wrote:
> Commit 8dce89a1c2cf ("clk: tegra: Don't warn for PLL defaults unnecessarily")
> changed the tegra210_pllcx_set_defaults() function causing the PLL to
> always be reset regardless of whether it is in-use. This function was
> changed so that resetting of the PLL will only be skipped if the PLL
> is enabled AND 'pllcx->params->defaults_set' is not true. However, the
> 'pllcx->params->defaults_set' is always true and hence, the PLL is now
> always reset. This causes the boot to fail on the Tegra210 Smaug where
> the PLL is already enabled and in-use. Fix this by only resetting the
> PLL if not in-use and only printing the warning that the defaults are
> not set after we have checked the default settings.
> 
> Fixes: 8dce89a1c2cf ("clk: tegra: Don't warn for PLL defaults unnecessarily")
> 
> Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
> ---
>  drivers/clk/tegra/clk-tegra210.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)

Applied to for-4.12/clk, thanks.

Thierry

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