diff mbox

[v3,1/3] ARM: da850: fix infinite loop in clk_set_rate()

Message ID 1480932549-30811-2-git-send-email-bgolaszewski@baylibre.com (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Bartosz Golaszewski Dec. 5, 2016, 10:09 a.m. UTC
The aemif clock is added twice to the lookup table in da850.c. This
breaks the children list of pll0_sysclk3 as we're using the same list
links in struct clk. When calling clk_set_rate(), we get stuck in
propagate_rate().

Create a separate clock for nand, inheriting the rate of the aemif
clock and retrieve it in the davinci_nand module.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/mach-davinci/da850.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Comments

Sekhar Nori Dec. 5, 2016, 10:15 a.m. UTC | #1
On Monday 05 December 2016 03:39 PM, Bartosz Golaszewski wrote:
> The aemif clock is added twice to the lookup table in da850.c. This
> breaks the children list of pll0_sysclk3 as we're using the same list
> links in struct clk. When calling clk_set_rate(), we get stuck in
> propagate_rate().
> 
> Create a separate clock for nand, inheriting the rate of the aemif
> clock and retrieve it in the davinci_nand module.
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---
>  arch/arm/mach-davinci/da850.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c
> index e770c97..c008e5e 100644
> --- a/arch/arm/mach-davinci/da850.c
> +++ b/arch/arm/mach-davinci/da850.c
> @@ -367,6 +367,11 @@ static struct clk aemif_clk = {
>  	.flags		= ALWAYS_ENABLED,
>  };
>  
> +static struct clk aemif_nand_clk = {
> +	.name		= "nand",
> +	.parent		= &aemif_clk,
> +};
> +
>  static struct clk usb11_clk = {
>  	.name		= "usb11",
>  	.parent		= &pll0_sysclk4,
> @@ -537,7 +542,7 @@ static struct clk_lookup da850_clks[] = {
>  	CLK("da830-mmc.0",	NULL,		&mmcsd0_clk),
>  	CLK("da830-mmc.1",	NULL,		&mmcsd1_clk),
>  	CLK("ti-aemif",		NULL,		&aemif_clk),
> -	CLK(NULL,		"aemif",	&aemif_clk),
> +	CLK(NULL,		"aemif",	&aemif_nand_clk),

Why use a NULL device name here? Same question was asked on v2
submission. Also, can you please make sure you are testing this in both
DT mode (da850-lcdk) and non-DT boot (da850-evm).

Thanks,
Sekhar
--
To unsubscribe from this list: send the line "unsubscribe linux-pm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Bartosz Golaszewski Dec. 5, 2016, 10:32 a.m. UTC | #2
2016-12-05 11:15 GMT+01:00 Sekhar Nori <nsekhar@ti.com>:
> On Monday 05 December 2016 03:39 PM, Bartosz Golaszewski wrote:
>> The aemif clock is added twice to the lookup table in da850.c. This
>> breaks the children list of pll0_sysclk3 as we're using the same list
>> links in struct clk. When calling clk_set_rate(), we get stuck in
>> propagate_rate().
>>
>> Create a separate clock for nand, inheriting the rate of the aemif
>> clock and retrieve it in the davinci_nand module.
>>
>> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>> ---
>>  arch/arm/mach-davinci/da850.c | 7 ++++++-
>>  1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c
>> index e770c97..c008e5e 100644
>> --- a/arch/arm/mach-davinci/da850.c
>> +++ b/arch/arm/mach-davinci/da850.c
>> @@ -367,6 +367,11 @@ static struct clk aemif_clk = {
>>       .flags          = ALWAYS_ENABLED,
>>  };
>>
>> +static struct clk aemif_nand_clk = {
>> +     .name           = "nand",
>> +     .parent         = &aemif_clk,
>> +};
>> +
>>  static struct clk usb11_clk = {
>>       .name           = "usb11",
>>       .parent         = &pll0_sysclk4,
>> @@ -537,7 +542,7 @@ static struct clk_lookup da850_clks[] = {
>>       CLK("da830-mmc.0",      NULL,           &mmcsd0_clk),
>>       CLK("da830-mmc.1",      NULL,           &mmcsd1_clk),
>>       CLK("ti-aemif",         NULL,           &aemif_clk),
>> -     CLK(NULL,               "aemif",        &aemif_clk),
>> +     CLK(NULL,               "aemif",        &aemif_nand_clk),
>
> Why use a NULL device name here? Same question was asked on v2

Eek, sorry, I missed that.

> submission. Also, can you please make sure you are testing this in both
> DT mode (da850-lcdk) and non-DT boot (da850-evm).

Will do.

Thanks,
Bartosz
--
To unsubscribe from this list: send the line "unsubscribe linux-pm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Sekhar Nori Dec. 5, 2016, 10:41 a.m. UTC | #3
On Monday 05 December 2016 04:02 PM, Bartosz Golaszewski wrote:
> 2016-12-05 11:15 GMT+01:00 Sekhar Nori <nsekhar@ti.com>:
>> On Monday 05 December 2016 03:39 PM, Bartosz Golaszewski wrote:
>>> The aemif clock is added twice to the lookup table in da850.c. This
>>> breaks the children list of pll0_sysclk3 as we're using the same list
>>> links in struct clk. When calling clk_set_rate(), we get stuck in
>>> propagate_rate().
>>>
>>> Create a separate clock for nand, inheriting the rate of the aemif
>>> clock and retrieve it in the davinci_nand module.
>>>
>>> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>>> ---
>>>  arch/arm/mach-davinci/da850.c | 7 ++++++-
>>>  1 file changed, 6 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c
>>> index e770c97..c008e5e 100644
>>> --- a/arch/arm/mach-davinci/da850.c
>>> +++ b/arch/arm/mach-davinci/da850.c
>>> @@ -367,6 +367,11 @@ static struct clk aemif_clk = {
>>>       .flags          = ALWAYS_ENABLED,
>>>  };
>>>
>>> +static struct clk aemif_nand_clk = {
>>> +     .name           = "nand",
>>> +     .parent         = &aemif_clk,
>>> +};
>>> +
>>>  static struct clk usb11_clk = {
>>>       .name           = "usb11",
>>>       .parent         = &pll0_sysclk4,
>>> @@ -537,7 +542,7 @@ static struct clk_lookup da850_clks[] = {
>>>       CLK("da830-mmc.0",      NULL,           &mmcsd0_clk),
>>>       CLK("da830-mmc.1",      NULL,           &mmcsd1_clk),
>>>       CLK("ti-aemif",         NULL,           &aemif_clk),
>>> -     CLK(NULL,               "aemif",        &aemif_clk),
>>> +     CLK(NULL,               "aemif",        &aemif_nand_clk),
>>
>> Why use a NULL device name here? Same question was asked on v2
> 
> Eek, sorry, I missed that.

For next version, can you also add a comment on top of 'struct clk
aemif_nand_clk' explaining why its needed?

Thanks,
Sekhar
--
To unsubscribe from this list: send the line "unsubscribe linux-pm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Bartosz Golaszewski Dec. 6, 2016, 11:58 a.m. UTC | #4
2016-12-05 11:15 GMT+01:00 Sekhar Nori <nsekhar@ti.com>:
> On Monday 05 December 2016 03:39 PM, Bartosz Golaszewski wrote:
>> The aemif clock is added twice to the lookup table in da850.c. This
>> breaks the children list of pll0_sysclk3 as we're using the same list
>> links in struct clk. When calling clk_set_rate(), we get stuck in
>> propagate_rate().
>>
>> Create a separate clock for nand, inheriting the rate of the aemif
>> clock and retrieve it in the davinci_nand module.
>>
>> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>> ---
>>  arch/arm/mach-davinci/da850.c | 7 ++++++-
>>  1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c
>> index e770c97..c008e5e 100644
>> --- a/arch/arm/mach-davinci/da850.c
>> +++ b/arch/arm/mach-davinci/da850.c
>> @@ -367,6 +367,11 @@ static struct clk aemif_clk = {
>>       .flags          = ALWAYS_ENABLED,
>>  };
>>
>> +static struct clk aemif_nand_clk = {
>> +     .name           = "nand",
>> +     .parent         = &aemif_clk,
>> +};
>> +
>>  static struct clk usb11_clk = {
>>       .name           = "usb11",
>>       .parent         = &pll0_sysclk4,
>> @@ -537,7 +542,7 @@ static struct clk_lookup da850_clks[] = {
>>       CLK("da830-mmc.0",      NULL,           &mmcsd0_clk),
>>       CLK("da830-mmc.1",      NULL,           &mmcsd1_clk),
>>       CLK("ti-aemif",         NULL,           &aemif_clk),
>> -     CLK(NULL,               "aemif",        &aemif_clk),
>> +     CLK(NULL,               "aemif",        &aemif_nand_clk),
>
> Why use a NULL device name here?

Hi Sekhar,

there's an issue with this bit. I added an of_dev_auxdata entry to
da8xx-dt.c for the nand node, but it didn't work (the nand driver
could not get the clock). When I dug deeper, it turned out, the nand
node is created from aemif_probe() instead of from
da850_init_machine() and the lookup table is not passed as argument to
of_platform_populate().

There are two solutions: one is using "620000000.nand" as dev_id in
the clock lookup table, but that's ugly. The second is leaving dev_id
as NULL - I verified that the nand driver works correctly having only
the connector id. Please let me know which one you prefer or if you
have other ideas.

Best regards,
Bartosz Golaszewski
--
To unsubscribe from this list: send the line "unsubscribe linux-pm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Sekhar Nori Dec. 6, 2016, 12:19 p.m. UTC | #5
On Tuesday 06 December 2016 05:28 PM, Bartosz Golaszewski wrote:
> 2016-12-05 11:15 GMT+01:00 Sekhar Nori <nsekhar@ti.com>:
>> On Monday 05 December 2016 03:39 PM, Bartosz Golaszewski wrote:
>>> The aemif clock is added twice to the lookup table in da850.c. This
>>> breaks the children list of pll0_sysclk3 as we're using the same list
>>> links in struct clk. When calling clk_set_rate(), we get stuck in
>>> propagate_rate().
>>>
>>> Create a separate clock for nand, inheriting the rate of the aemif
>>> clock and retrieve it in the davinci_nand module.
>>>
>>> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>>> ---
>>>  arch/arm/mach-davinci/da850.c | 7 ++++++-
>>>  1 file changed, 6 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c
>>> index e770c97..c008e5e 100644
>>> --- a/arch/arm/mach-davinci/da850.c
>>> +++ b/arch/arm/mach-davinci/da850.c
>>> @@ -367,6 +367,11 @@ static struct clk aemif_clk = {
>>>       .flags          = ALWAYS_ENABLED,
>>>  };
>>>
>>> +static struct clk aemif_nand_clk = {
>>> +     .name           = "nand",
>>> +     .parent         = &aemif_clk,
>>> +};
>>> +
>>>  static struct clk usb11_clk = {
>>>       .name           = "usb11",
>>>       .parent         = &pll0_sysclk4,
>>> @@ -537,7 +542,7 @@ static struct clk_lookup da850_clks[] = {
>>>       CLK("da830-mmc.0",      NULL,           &mmcsd0_clk),
>>>       CLK("da830-mmc.1",      NULL,           &mmcsd1_clk),
>>>       CLK("ti-aemif",         NULL,           &aemif_clk),
>>> -     CLK(NULL,               "aemif",        &aemif_clk),
>>> +     CLK(NULL,               "aemif",        &aemif_nand_clk),
>>
>> Why use a NULL device name here?
> 
> Hi Sekhar,
> 
> there's an issue with this bit. I added an of_dev_auxdata entry to
> da8xx-dt.c for the nand node, but it didn't work (the nand driver
> could not get the clock). When I dug deeper, it turned out, the nand
> node is created from aemif_probe() instead of from
> da850_init_machine() and the lookup table is not passed as argument to
> of_platform_populate().
> 
> There are two solutions: one is using "620000000.nand" as dev_id in
> the clock lookup table, but that's ugly. The second is leaving dev_id
> as NULL - I verified that the nand driver works correctly having only
> the connector id. Please let me know which one you prefer or if you
> have other ideas.

Alright, I will take a look at whats going on here. This series will
have to wait for v4.11 anyway.

Thanks,
Sekhar
--
To unsubscribe from this list: send the line "unsubscribe linux-pm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
David Lechner Dec. 7, 2016, 1:54 a.m. UTC | #6
On 12/05/2016 04:09 AM, Bartosz Golaszewski wrote:
> The aemif clock is added twice to the lookup table in da850.c. This
> breaks the children list of pll0_sysclk3 as we're using the same list
> links in struct clk. When calling clk_set_rate(), we get stuck in
> propagate_rate().

&emac_clk is used twice in this list as well. Shouldn't we fix it too? I 
would expect that it causes the same problem.

>
> Create a separate clock for nand, inheriting the rate of the aemif
> clock and retrieve it in the davinci_nand module.
>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---
>  arch/arm/mach-davinci/da850.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c
> index e770c97..c008e5e 100644
> --- a/arch/arm/mach-davinci/da850.c
> +++ b/arch/arm/mach-davinci/da850.c
> @@ -367,6 +367,11 @@ static struct clk aemif_clk = {
>  	.flags		= ALWAYS_ENABLED,
>  };
>
> +static struct clk aemif_nand_clk = {
> +	.name		= "nand",
> +	.parent		= &aemif_clk,
> +};
> +
>  static struct clk usb11_clk = {
>  	.name		= "usb11",
>  	.parent		= &pll0_sysclk4,
> @@ -537,7 +542,7 @@ static struct clk_lookup da850_clks[] = {
>  	CLK("da830-mmc.0",	NULL,		&mmcsd0_clk),
>  	CLK("da830-mmc.1",	NULL,		&mmcsd1_clk),
>  	CLK("ti-aemif",		NULL,		&aemif_clk),
> -	CLK(NULL,		"aemif",	&aemif_clk),
> +	CLK(NULL,		"aemif",	&aemif_nand_clk),
>  	CLK("ohci-da8xx",	"usb11",	&usb11_clk),
>  	CLK("musb-da8xx",	"usb20",	&usb20_clk),
>  	CLK("spi_davinci.0",	NULL,		&spi0_clk),
>

--
To unsubscribe from this list: send the line "unsubscribe linux-pm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Sekhar Nori Dec. 7, 2016, 6:30 a.m. UTC | #7
On Wednesday 07 December 2016 07:24 AM, David Lechner wrote:
> On 12/05/2016 04:09 AM, Bartosz Golaszewski wrote:
>> The aemif clock is added twice to the lookup table in da850.c. This
>> breaks the children list of pll0_sysclk3 as we're using the same list
>> links in struct clk. When calling clk_set_rate(), we get stuck in
>> propagate_rate().
> 
> &emac_clk is used twice in this list as well. Shouldn't we fix it too? I
> would expect that it causes the same problem.

Yes, indeed.

Thanks,
Sekhar
--
To unsubscribe from this list: send the line "unsubscribe linux-pm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c
index e770c97..c008e5e 100644
--- a/arch/arm/mach-davinci/da850.c
+++ b/arch/arm/mach-davinci/da850.c
@@ -367,6 +367,11 @@  static struct clk aemif_clk = {
 	.flags		= ALWAYS_ENABLED,
 };
 
+static struct clk aemif_nand_clk = {
+	.name		= "nand",
+	.parent		= &aemif_clk,
+};
+
 static struct clk usb11_clk = {
 	.name		= "usb11",
 	.parent		= &pll0_sysclk4,
@@ -537,7 +542,7 @@  static struct clk_lookup da850_clks[] = {
 	CLK("da830-mmc.0",	NULL,		&mmcsd0_clk),
 	CLK("da830-mmc.1",	NULL,		&mmcsd1_clk),
 	CLK("ti-aemif",		NULL,		&aemif_clk),
-	CLK(NULL,		"aemif",	&aemif_clk),
+	CLK(NULL,		"aemif",	&aemif_nand_clk),
 	CLK("ohci-da8xx",	"usb11",	&usb11_clk),
 	CLK("musb-da8xx",	"usb20",	&usb20_clk),
 	CLK("spi_davinci.0",	NULL,		&spi0_clk),