2015-12-18 13:45:37

by Jon Hunter

Subject: [PATCH] clk: tegra: Fix clock sources for tegra210 EMC

The EMC clock sources for tegra210 currently incorrectly include pll_c2
and pll_c3. However, both of these should have been pll_mb as shown in
the TRM. If tegra210 happens to be configured such that the pll_mb is the
default clock for the EMC, as configured by the bootloader, then this will
cause a system hang on boot. This is because the kernel will disable the
pll_mb when disabling unused clock as it appears to be unused when it is
not.

Also add the additional pll_p clock source for the EMC.

Signed-off-by: Jon Hunter <[email protected]>
---
drivers/clk/tegra/clk-tegra210.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/tegra/clk-tegra210.c b/drivers/clk/tegra/clk-tegra210.c
index 58514c44ea83..849be30b52bf 100644
--- a/drivers/clk/tegra/clk-tegra210.c
+++ b/drivers/clk/tegra/clk-tegra210.c
@@ -243,7 +243,8 @@ static unsigned long tegra210_input_freq[] = {
};

static const char *mux_pllmcp_clkm[] = {
- "pll_m", "pll_c", "pll_p", "clk_m", "pll_m_ud", "pll_c2", "pll_c3",
+ "pll_m", "pll_c", "pll_p", "clk_m", "pll_m_ud", "pll_mb", "pll_mb",
+ "pll_p",
};
#define mux_pllmcp_clkm_idx NULL

--
2.1.4

2015-12-18 16:49:16

by Rhyland Klein

Subject: Re: [PATCH] clk: tegra: Fix clock sources for tegra210 EMC

On 12/18/2015 8:45 AM, Jon Hunter wrote:
> The EMC clock sources for tegra210 currently incorrectly include pll_c2
> and pll_c3. However, both of these should have been pll_mb as shown in
> the TRM. If tegra210 happens to be configured such that the pll_mb is the
> default clock for the EMC, as configured by the bootloader, then this will
> cause a system hang on boot. This is because the kernel will disable the
> pll_mb when disabling unused clock as it appears to be unused when it is
> not.
>
> Also add the additional pll_p clock source for the EMC.
>
> Signed-off-by: Jon Hunter <[email protected]>
> ---
> drivers/clk/tegra/clk-tegra210.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/tegra/clk-tegra210.c b/drivers/clk/tegra/clk-tegra210.c
> index 58514c44ea83..849be30b52bf 100644
> --- a/drivers/clk/tegra/clk-tegra210.c
> +++ b/drivers/clk/tegra/clk-tegra210.c
> @@ -243,7 +243,8 @@ static unsigned long tegra210_input_freq[] = {
> };
>
> static const char *mux_pllmcp_clkm[] = {
> - "pll_m", "pll_c", "pll_p", "clk_m", "pll_m_ud", "pll_c2", "pll_c3",
> + "pll_m", "pll_c", "pll_p", "clk_m", "pll_m_ud", "pll_mb", "pll_mb",
> + "pll_p",
> };
> #define mux_pllmcp_clkm_idx NULL
>
>

Acked-by: Rhyland Klein <[email protected]>

-rhyland

--
nvpublic