2015-08-07 20:59:28

by Dmitry Torokhov

Subject: [PATCH] thermal: rockchip: fix handling of invalid readings

We attempted to signal invalid code by returning -EAGAIN from
rk_tsadcv2_code_to_temp(), unfortunately the return value was stuffed
directly into the temperature pointer, potentially confusing upper
layers with temperature of -EINVAL.

Let's split temperature from error/success indicator to avoid such
confusion.

Also change the way we scan the temperature table to start with the 2nd
element so that we do not need to worry that we may reference out of
bounds element while doing binary search and keep checking that we end
up with 'mid' equal to 0 (since we are looking for the temperature that
would fall into interval between the 'mid' and 'mid - 1') .

Signed-off-by: Dmitry Torokhov <[email protected]>
---
drivers/thermal/rockchip_thermal.c | 28 +++++++++++++---------------
1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c
index c89ffb2..93ee307 100644
--- a/drivers/thermal/rockchip_thermal.c
+++ b/drivers/thermal/rockchip_thermal.c
@@ -124,7 +124,7 @@ struct rockchip_thermal_data {
#define TSADCV2_AUTO_PERIOD_HT_TIME 50 /* msec */

struct tsadc_table {
- unsigned long code;
+ u32 code;
long temp;
};

@@ -164,7 +164,6 @@ static const struct tsadc_table v2_code_table[] = {
{3452, 115000},
{3437, 120000},
{3421, 125000},
- {0, 125000},
};

static u32 rk_tsadcv2_temp_to_code(long temp)
@@ -191,19 +190,21 @@ static u32 rk_tsadcv2_temp_to_code(long temp)
return 0;
}

-static int rk_tsadcv2_code_to_temp(u32 code)
+static int rk_tsadcv2_code_to_temp(u32 code, int *temp)
{
- unsigned int low = 0;
+ unsigned int low = 1;
unsigned int high = ARRAY_SIZE(v2_code_table) - 1;
unsigned int mid = (low + high) / 2;
unsigned int num;
unsigned long denom;

- /* Invalid code, return -EAGAIN */
- if (code > TSADCV2_DATA_MASK)
- return -EAGAIN;
+ BUILD_BUG_ON(ARRAY_SIZE(v2_code_table) < 2);

- while (low <= high && mid) {
+ code &= TSADCV2_DATA_MASK;
+ if (code < v2_code_table[high].code)
+ return -EAGAIN; /* Incorrect reading */
+
+ while (low <= high) {
if (code >= v2_code_table[mid].code &&
code < v2_code_table[mid - 1].code)
break;
@@ -223,7 +224,9 @@ static int rk_tsadcv2_code_to_temp(u32 code)
num = v2_code_table[mid].temp - v2_code_table[mid - 1].temp;
num *= v2_code_table[mid - 1].code - code;
denom = v2_code_table[mid - 1].code - v2_code_table[mid].code;
- return v2_code_table[mid - 1].temp + (num / denom);
+ *temp = v2_code_table[mid - 1].temp + (num / denom);
+
+ return 0;
}

/**
@@ -281,14 +284,9 @@ static int rk_tsadcv2_get_temp(int chn, void __iomem *regs, int *temp)
{
u32 val;

- /* the A/D value of the channel last conversion need some time */
val = readl_relaxed(regs + TSADCV2_DATA(chn));
- if (val == 0)
- return -EAGAIN;
-
- *temp = rk_tsadcv2_code_to_temp(val);

- return 0;
+ return rk_tsadcv2_code_to_temp(val, temp);
}

static void rk_tsadcv2_tshut_temp(int chn, void __iomem *regs, long temp)
--
2.5.0.rc2.392.g76e840b


--
Dmitry

2015-08-10 06:31:50

by Caesar Wang

Subject: Re: [PATCH] thermal: rockchip: fix handling of invalid readings

Dear Dmitry,

Thanks your patch.

The code looks like fine,but I don't think the TS-ADC will work on
rk3288 SoC.

在 2015年08月08日 04:59, Dmitry Torokhov 写道:
> We attempted to signal invalid code by returning -EAGAIN from
> rk_tsadcv2_code_to_temp(), unfortunately the return value was stuffed
> directly into the temperature pointer, potentially confusing upper
> layers with temperature of -EINVAL.
>
> Let's split temperature from error/success indicator to avoid such
> confusion.
>
> Also change the way we scan the temperature table to start with the 2nd
> element so that we do not need to worry that we may reference out of
> bounds element while doing binary search and keep checking that we end
> up with 'mid' equal to 0 (since we are looking for the temperature that
> would fall into interval between the 'mid' and 'mid - 1') .
>
> Signed-off-by: Dmitry Torokhov <[email protected]>
> ---
> drivers/thermal/rockchip_thermal.c | 28 +++++++++++++---------------
> 1 file changed, 13 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c
> index c89ffb2..93ee307 100644
> --- a/drivers/thermal/rockchip_thermal.c
> +++ b/drivers/thermal/rockchip_thermal.c
> @@ -124,7 +124,7 @@ struct rockchip_thermal_data {
> #define TSADCV2_AUTO_PERIOD_HT_TIME 50 /* msec */
>
> struct tsadc_table {
> - unsigned long code;
> + u32 code;
> long temp;
> };
>
> @@ -164,7 +164,6 @@ static const struct tsadc_table v2_code_table[] = {
> {3452, 115000},
> {3437, 120000},
> {3421, 125000},
> - {0, 125000},
> };
>
> static u32 rk_tsadcv2_temp_to_code(long temp)
> @@ -191,19 +190,21 @@ static u32 rk_tsadcv2_temp_to_code(long temp)
> return 0;
> }
>
> -static int rk_tsadcv2_code_to_temp(u32 code)
> +static int rk_tsadcv2_code_to_temp(u32 code, int *temp)
> {
> - unsigned int low = 0;
> + unsigned int low = 1;
> unsigned int high = ARRAY_SIZE(v2_code_table) - 1;
> unsigned int mid = (low + high) / 2;
> unsigned int num;
> unsigned long denom;
>
> - /* Invalid code, return -EAGAIN */
> - if (code > TSADCV2_DATA_MASK)
> - return -EAGAIN;
> + BUILD_BUG_ON(ARRAY_SIZE(v2_code_table) < 2);
>
> - while (low <= high && mid) {
> + code &= TSADCV2_DATA_MASK;
> + if (code < v2_code_table[high].code)
> + return -EAGAIN; /* Incorrect reading */
> +
> + while (low <= high) {
> if (code >= v2_code_table[mid].code &&
> code < v2_code_table[mid - 1].code)
> break;
> @@ -223,7 +224,9 @@ static int rk_tsadcv2_code_to_temp(u32 code)
> num = v2_code_table[mid].temp - v2_code_table[mid - 1].temp;
> num *= v2_code_table[mid - 1].code - code;
> denom = v2_code_table[mid - 1].code - v2_code_table[mid].code;
> - return v2_code_table[mid - 1].temp + (num / denom);
> + *temp = v2_code_table[mid - 1].temp + (num / denom);
> +
> + return 0;
> }
>
> /**
> @@ -281,14 +284,9 @@ static int rk_tsadcv2_get_temp(int chn, void __iomem *regs, int *temp)
> {
> u32 val;
>
> - /* the A/D value of the channel last conversion need some time */
> val = readl_relaxed(regs + TSADCV2_DATA(chn));
> - if (val == 0)
> - return -EAGAIN;
> -

if we reserve the above code, that will get the ADC value.

> - *temp = rk_tsadcv2_code_to_temp(val);
>
> - return 0;
> + return rk_tsadcv2_code_to_temp(val, temp);
> }
>
> static void rk_tsadcv2_tshut_temp(int chn, void __iomem *regs, long temp)

2015-08-10 07:59:11

by Dmitry Torokhov

Subject: Re: [PATCH] thermal: rockchip: fix handling of invalid readings

Hi Caesar,

On Sun, Aug 9, 2015 at 11:30 PM, Caesar Wang <[email protected]> wrote:
> Dear Dmitry,
>
> Thanks your patch.
>
> The code looks like fine,but I don't think the TS-ADC will work on rk3288
> SoC.

What do you mean? It seems to work when I ran it...

>
>
> 在 2015年08月08日 04:59, Dmitry Torokhov 写道:
>>
>> We attempted to signal invalid code by returning -EAGAIN from
>> rk_tsadcv2_code_to_temp(), unfortunately the return value was stuffed
>> directly into the temperature pointer, potentially confusing upper
>> layers with temperature of -EINVAL.
>>
>> Let's split temperature from error/success indicator to avoid such
>> confusion.
>>
>> Also change the way we scan the temperature table to start with the 2nd
>> element so that we do not need to worry that we may reference out of
>> bounds element while doing binary search and keep checking that we end
>> up with 'mid' equal to 0 (since we are looking for the temperature that
>> would fall into interval between the 'mid' and 'mid - 1') .
>>
>> Signed-off-by: Dmitry Torokhov <[email protected]>
>> ---
>> drivers/thermal/rockchip_thermal.c | 28 +++++++++++++---------------
>> 1 file changed, 13 insertions(+), 15 deletions(-)
>>
>> diff --git a/drivers/thermal/rockchip_thermal.c
>> b/drivers/thermal/rockchip_thermal.c
>> index c89ffb2..93ee307 100644
>> --- a/drivers/thermal/rockchip_thermal.c
>> +++ b/drivers/thermal/rockchip_thermal.c
>> @@ -124,7 +124,7 @@ struct rockchip_thermal_data {
>> #define TSADCV2_AUTO_PERIOD_HT_TIME 50 /* msec */
>> struct tsadc_table {
>> - unsigned long code;
>> + u32 code;
>> long temp;
>> };
>> @@ -164,7 +164,6 @@ static const struct tsadc_table v2_code_table[] = {
>> {3452, 115000},
>> {3437, 120000},
>> {3421, 125000},
>> - {0, 125000},
>> };
>> static u32 rk_tsadcv2_temp_to_code(long temp)
>> @@ -191,19 +190,21 @@ static u32 rk_tsadcv2_temp_to_code(long temp)
>> return 0;
>> }
>> -static int rk_tsadcv2_code_to_temp(u32 code)
>> +static int rk_tsadcv2_code_to_temp(u32 code, int *temp)
>> {
>> - unsigned int low = 0;
>> + unsigned int low = 1;
>> unsigned int high = ARRAY_SIZE(v2_code_table) - 1;
>> unsigned int mid = (low + high) / 2;
>> unsigned int num;
>> unsigned long denom;
>> - /* Invalid code, return -EAGAIN */
>> - if (code > TSADCV2_DATA_MASK)
>> - return -EAGAIN;
>> + BUILD_BUG_ON(ARRAY_SIZE(v2_code_table) < 2);
>> - while (low <= high && mid) {
>> + code &= TSADCV2_DATA_MASK;
>> + if (code < v2_code_table[high].code)
>> + return -EAGAIN; /* Incorrect reading */
>> +
>> + while (low <= high) {
>> if (code >= v2_code_table[mid].code &&
>> code < v2_code_table[mid - 1].code)
>> break;
>> @@ -223,7 +224,9 @@ static int rk_tsadcv2_code_to_temp(u32 code)
>> num = v2_code_table[mid].temp - v2_code_table[mid - 1].temp;
>> num *= v2_code_table[mid - 1].code - code;
>> denom = v2_code_table[mid - 1].code - v2_code_table[mid].code;
>> - return v2_code_table[mid - 1].temp + (num / denom);
>> + *temp = v2_code_table[mid - 1].temp + (num / denom);
>> +
>> + return 0;
>> }
>> /**
>> @@ -281,14 +284,9 @@ static int rk_tsadcv2_get_temp(int chn, void __iomem
>> *regs, int *temp)
>> {
>> u32 val;
>> - /* the A/D value of the channel last conversion need some time */
>> val = readl_relaxed(regs + TSADCV2_DATA(chn));
>> - if (val == 0)
>> - return -EAGAIN;
>> -
>
>
> if we reserve the above code, that will get the ADC value.

But if we pass 0 into rk_tsadcv2_code_to_temp() it will trigger:

>> + if (code < v2_code_table[high].code)
>> + return -EAGAIN; /* Incorrect reading */

and still return -EAGAIN, as it was. There is no behavior change as
far as I can see.

>
>
>> - *temp = rk_tsadcv2_code_to_temp(val);
>> - return 0;
>> + return rk_tsadcv2_code_to_temp(val, temp);
>> }
>> static void rk_tsadcv2_tshut_temp(int chn, void __iomem *regs, long
>> temp)
>
>

Thanks,
Dmitry

2015-08-10 10:22:59

by Caesar Wang

Subject: Re: [PATCH] thermal: rockchip: fix handling of invalid readings

在 2015年08月10日 15:59, Dmitry Torokhov 写道:
> Hi Caesar,
>
> On Sun, Aug 9, 2015 at 11:30 PM, Caesar Wang <[email protected]> wrote:
>> Dear Dmitry,
>>
>> Thanks your patch.
>>
>> The code looks like fine,but I don't think the TS-ADC will work on rk3288
>> SoC.
> What do you mean? It seems to work when I ran it...

Making a mistake.:-(

>>
>> 在 2015年08月08日 04:59, Dmitry Torokhov 写道:
>>> We attempted to signal invalid code by returning -EAGAIN from
>>> rk_tsadcv2_code_to_temp(), unfortunately the return value was stuffed
>>> directly into the temperature pointer, potentially confusing upper
>>> layers with temperature of -EINVAL.
>>>
>>> Let's split temperature from error/success indicator to avoid such
>>> confusion.
>>>
>>> Also change the way we scan the temperature table to start with the 2nd
>>> element so that we do not need to worry that we may reference out of
>>> bounds element while doing binary search and keep checking that we end
>>> up with 'mid' equal to 0 (since we are looking for the temperature that
>>> would fall into interval between the 'mid' and 'mid - 1') .
>>>
>>> Signed-off-by: Dmitry Torokhov <[email protected]>
>>> ---
>>> drivers/thermal/rockchip_thermal.c | 28 +++++++++++++---------------
>>> 1 file changed, 13 insertions(+), 15 deletions(-)
>>>
>>> diff --git a/drivers/thermal/rockchip_thermal.c
>>> b/drivers/thermal/rockchip_thermal.c
>>> index c89ffb2..93ee307 100644
>>> --- a/drivers/thermal/rockchip_thermal.c
>>> +++ b/drivers/thermal/rockchip_thermal.c
>>> @@ -124,7 +124,7 @@ struct rockchip_thermal_data {
>>> #define TSADCV2_AUTO_PERIOD_HT_TIME 50 /* msec */
>>> struct tsadc_table {
>>> - unsigned long code;
>>> + u32 code;
>>> long temp;
>>> };
>>> @@ -164,7 +164,6 @@ static const struct tsadc_table v2_code_table[] = {
>>> {3452, 115000},
>>> {3437, 120000},
>>> {3421, 125000},
>>> - {0, 125000},
>>> };
>>> static u32 rk_tsadcv2_temp_to_code(long temp)
>>> @@ -191,19 +190,21 @@ static u32 rk_tsadcv2_temp_to_code(long temp)
>>> return 0;
>>> }
>>> -static int rk_tsadcv2_code_to_temp(u32 code)
>>> +static int rk_tsadcv2_code_to_temp(u32 code, int *temp)

It's wired that can't git-am this patch.

I search the Eduardo'branch[0] for rockchip-thermal.c driver. The
function is "static long rk_tsadcv2_code_to_temp(u32 code)"

Maybe i'm missing something, I verified this patch on my board but this
fixed.

So you can free add it:
Tested-by: Caesar Wang <[email protected]>

[0]:
url =
git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal.git



---
Thanks,
Caesar



>>> {
>>> - unsigned int low = 0;
>>> + unsigned int low = 1;
>>> unsigned int high = ARRAY_SIZE(v2_code_table) - 1;
>>> unsigned int mid = (low + high) / 2;
>>> unsigned int num;
>>> unsigned long denom;
>>> - /* Invalid code, return -EAGAIN */
>>> - if (code > TSADCV2_DATA_MASK)
>>> - return -EAGAIN;
>>> + BUILD_BUG_ON(ARRAY_SIZE(v2_code_table) < 2);
>>> - while (low <= high && mid) {
>>> + code &= TSADCV2_DATA_MASK;
>>> + if (code < v2_code_table[high].code)
>>> + return -EAGAIN; /* Incorrect reading */
>>> +
>>> + while (low <= high) {
>>> if (code >= v2_code_table[mid].code &&
>>> code < v2_code_table[mid - 1].code)
>>> break;
>>> @@ -223,7 +224,9 @@ static int rk_tsadcv2_code_to_temp(u32 code)
>>> num = v2_code_table[mid].temp - v2_code_table[mid - 1].temp;
>>> num *= v2_code_table[mid - 1].code - code;
>>> denom = v2_code_table[mid - 1].code - v2_code_table[mid].code;
>>> - return v2_code_table[mid - 1].temp + (num / denom);
>>> + *temp = v2_code_table[mid - 1].temp + (num / denom);
>>> +
>>> + return 0;
>>> }
>>> /**
>>> @@ -281,14 +284,9 @@ static int rk_tsadcv2_get_temp(int chn, void __iomem
>>> *regs, int *temp)
>>> {
>>> u32 val;
>>> - /* the A/D value of the channel last conversion need some time */
>>> val = readl_relaxed(regs + TSADCV2_DATA(chn));
>>> - if (val == 0)
>>> - return -EAGAIN;
>>> -
>>
>> if we reserve the above code, that will get the ADC value.
> But if we pass 0 into rk_tsadcv2_code_to_temp() it will trigger:
>
>>> + if (code < v2_code_table[high].code)
>>> + return -EAGAIN; /* Incorrect reading */
> and still return -EAGAIN, as it was. There is no behavior change as
> far as I can see.
Yup, that's ok for me.

>>
>>> - *temp = rk_tsadcv2_code_to_temp(val);
>>> - return 0;
>>> + return rk_tsadcv2_code_to_temp(val, temp);
>>> }
>>> static void rk_tsadcv2_tshut_temp(int chn, void __iomem *regs, long
>>> temp)
>>
> Thanks,
> Dmitry
>
>
>