Simplify using the devm_regulator_get_enable_optional(). Also drop the
seemingly unused struct member 'hdmi_supply'.
Signed-off-by: Matti Vaittinen <[email protected]>
---
v3 => v4:
- split meson part to own patch
RFCv1 => v2:
- Change also sii902x to use devm_regulator_bulk_get_enable()
Please note - this is only compile-tested due to the lack of HW. Careful
review and testing is _highly_ appreciated.
---
drivers/gpu/drm/meson/meson_dw_hdmi.c | 23 +++--------------------
1 file changed, 3 insertions(+), 20 deletions(-)
diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
index 5cd2b2ebbbd3..7642f740272b 100644
--- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
+++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
@@ -140,7 +140,6 @@ struct meson_dw_hdmi {
struct reset_control *hdmitx_apb;
struct reset_control *hdmitx_ctrl;
struct reset_control *hdmitx_phy;
- struct regulator *hdmi_supply;
u32 irq_stat;
struct dw_hdmi *hdmi;
struct drm_bridge *bridge;
@@ -665,11 +664,6 @@ static void meson_dw_hdmi_init(struct meson_dw_hdmi *meson_dw_hdmi)
}
-static void meson_disable_regulator(void *data)
-{
- regulator_disable(data);
-}
-
static void meson_disable_clk(void *data)
{
clk_disable_unprepare(data);
@@ -723,20 +717,9 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
meson_dw_hdmi->data = match;
dw_plat_data = &meson_dw_hdmi->dw_plat_data;
- meson_dw_hdmi->hdmi_supply = devm_regulator_get_optional(dev, "hdmi");
- if (IS_ERR(meson_dw_hdmi->hdmi_supply)) {
- if (PTR_ERR(meson_dw_hdmi->hdmi_supply) == -EPROBE_DEFER)
- return -EPROBE_DEFER;
- meson_dw_hdmi->hdmi_supply = NULL;
- } else {
- ret = regulator_enable(meson_dw_hdmi->hdmi_supply);
- if (ret)
- return ret;
- ret = devm_add_action_or_reset(dev, meson_disable_regulator,
- meson_dw_hdmi->hdmi_supply);
- if (ret)
- return ret;
- }
+ ret = devm_regulator_get_enable_optional(dev, "hdmi");
+ if (ret != -ENODEV)
+ return ret;
meson_dw_hdmi->hdmitx_apb = devm_reset_control_get_exclusive(dev,
"hdmitx_apb");
--
2.37.3
--
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND
~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =]
On 21/10/2022 15:18, Matti Vaittinen wrote:
> Simplify using the devm_regulator_get_enable_optional(). Also drop the
> seemingly unused struct member 'hdmi_supply'.
>
> Signed-off-by: Matti Vaittinen <[email protected]>
>
> ---
> v3 => v4:
> - split meson part to own patch
>
> RFCv1 => v2:
> - Change also sii902x to use devm_regulator_bulk_get_enable()
>
> Please note - this is only compile-tested due to the lack of HW. Careful
> review and testing is _highly_ appreciated.
> ---
> drivers/gpu/drm/meson/meson_dw_hdmi.c | 23 +++--------------------
> 1 file changed, 3 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> index 5cd2b2ebbbd3..7642f740272b 100644
> --- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
> +++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> @@ -140,7 +140,6 @@ struct meson_dw_hdmi {
> struct reset_control *hdmitx_apb;
> struct reset_control *hdmitx_ctrl;
> struct reset_control *hdmitx_phy;
> - struct regulator *hdmi_supply;
> u32 irq_stat;
> struct dw_hdmi *hdmi;
> struct drm_bridge *bridge;
> @@ -665,11 +664,6 @@ static void meson_dw_hdmi_init(struct meson_dw_hdmi *meson_dw_hdmi)
>
> }
>
> -static void meson_disable_regulator(void *data)
> -{
> - regulator_disable(data);
> -}
> -
> static void meson_disable_clk(void *data)
> {
> clk_disable_unprepare(data);
> @@ -723,20 +717,9 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
> meson_dw_hdmi->data = match;
> dw_plat_data = &meson_dw_hdmi->dw_plat_data;
>
> - meson_dw_hdmi->hdmi_supply = devm_regulator_get_optional(dev, "hdmi");
> - if (IS_ERR(meson_dw_hdmi->hdmi_supply)) {
> - if (PTR_ERR(meson_dw_hdmi->hdmi_supply) == -EPROBE_DEFER)
> - return -EPROBE_DEFER;
> - meson_dw_hdmi->hdmi_supply = NULL;
> - } else {
> - ret = regulator_enable(meson_dw_hdmi->hdmi_supply);
> - if (ret)
> - return ret;
> - ret = devm_add_action_or_reset(dev, meson_disable_regulator,
> - meson_dw_hdmi->hdmi_supply);
> - if (ret)
> - return ret;
> - }
> + ret = devm_regulator_get_enable_optional(dev, "hdmi");
> + if (ret != -ENODEV)
> + return ret;
>
> meson_dw_hdmi->hdmitx_apb = devm_reset_control_get_exclusive(dev,
> "hdmitx_apb");
Reviewed-by: Neil Armstrong <[email protected]>
Hi Matti,
On Fri, Oct 21, 2022 at 04:18:01PM +0300, Matti Vaittinen wrote:
> Simplify using the devm_regulator_get_enable_optional(). Also drop the
> seemingly unused struct member 'hdmi_supply'.
>
> Signed-off-by: Matti Vaittinen <[email protected]>
>
> ---
> v3 => v4:
> - split meson part to own patch
>
> RFCv1 => v2:
> - Change also sii902x to use devm_regulator_bulk_get_enable()
>
> Please note - this is only compile-tested due to the lack of HW. Careful
> review and testing is _highly_ appreciated.
> ---
> drivers/gpu/drm/meson/meson_dw_hdmi.c | 23 +++--------------------
> 1 file changed, 3 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> index 5cd2b2ebbbd3..7642f740272b 100644
> --- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
> +++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> @@ -140,7 +140,6 @@ struct meson_dw_hdmi {
> struct reset_control *hdmitx_apb;
> struct reset_control *hdmitx_ctrl;
> struct reset_control *hdmitx_phy;
> - struct regulator *hdmi_supply;
> u32 irq_stat;
> struct dw_hdmi *hdmi;
> struct drm_bridge *bridge;
> @@ -665,11 +664,6 @@ static void meson_dw_hdmi_init(struct meson_dw_hdmi *meson_dw_hdmi)
>
> }
>
> -static void meson_disable_regulator(void *data)
> -{
> - regulator_disable(data);
> -}
> -
> static void meson_disable_clk(void *data)
> {
> clk_disable_unprepare(data);
> @@ -723,20 +717,9 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
> meson_dw_hdmi->data = match;
> dw_plat_data = &meson_dw_hdmi->dw_plat_data;
>
> - meson_dw_hdmi->hdmi_supply = devm_regulator_get_optional(dev, "hdmi");
> - if (IS_ERR(meson_dw_hdmi->hdmi_supply)) {
> - if (PTR_ERR(meson_dw_hdmi->hdmi_supply) == -EPROBE_DEFER)
> - return -EPROBE_DEFER;
> - meson_dw_hdmi->hdmi_supply = NULL;
> - } else {
> - ret = regulator_enable(meson_dw_hdmi->hdmi_supply);
> - if (ret)
> - return ret;
> - ret = devm_add_action_or_reset(dev, meson_disable_regulator,
> - meson_dw_hdmi->hdmi_supply);
> - if (ret)
> - return ret;
> - }
> + ret = devm_regulator_get_enable_optional(dev, "hdmi");
> + if (ret != -ENODEV)
> + return ret;
As noted in the review of the series that introduced
devm_regulator_get_enable_optional(), the right thing to do is to
implement runtime PM in this driver to avoid wasting power.
>
> meson_dw_hdmi->hdmitx_apb = devm_reset_control_get_exclusive(dev,
> "hdmitx_apb");
--
Regards,
Laurent Pinchart
Hi,
On 21/10/2022 17:02, Laurent Pinchart wrote:
> Hi Matti,
>
> On Fri, Oct 21, 2022 at 04:18:01PM +0300, Matti Vaittinen wrote:
>> Simplify using the devm_regulator_get_enable_optional(). Also drop the
>> seemingly unused struct member 'hdmi_supply'.
>>
>> Signed-off-by: Matti Vaittinen <[email protected]>
>>
>> ---
>> v3 => v4:
>> - split meson part to own patch
>>
>> RFCv1 => v2:
>> - Change also sii902x to use devm_regulator_bulk_get_enable()
>>
>> Please note - this is only compile-tested due to the lack of HW. Careful
>> review and testing is _highly_ appreciated.
>> ---
>> drivers/gpu/drm/meson/meson_dw_hdmi.c | 23 +++--------------------
>> 1 file changed, 3 insertions(+), 20 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
>> index 5cd2b2ebbbd3..7642f740272b 100644
>> --- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
>> +++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
>> @@ -140,7 +140,6 @@ struct meson_dw_hdmi {
>> struct reset_control *hdmitx_apb;
>> struct reset_control *hdmitx_ctrl;
>> struct reset_control *hdmitx_phy;
>> - struct regulator *hdmi_supply;
>> u32 irq_stat;
>> struct dw_hdmi *hdmi;
>> struct drm_bridge *bridge;
>> @@ -665,11 +664,6 @@ static void meson_dw_hdmi_init(struct meson_dw_hdmi *meson_dw_hdmi)
>>
>> }
>>
>> -static void meson_disable_regulator(void *data)
>> -{
>> - regulator_disable(data);
>> -}
>> -
>> static void meson_disable_clk(void *data)
>> {
>> clk_disable_unprepare(data);
>> @@ -723,20 +717,9 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
>> meson_dw_hdmi->data = match;
>> dw_plat_data = &meson_dw_hdmi->dw_plat_data;
>>
>> - meson_dw_hdmi->hdmi_supply = devm_regulator_get_optional(dev, "hdmi");
>> - if (IS_ERR(meson_dw_hdmi->hdmi_supply)) {
>> - if (PTR_ERR(meson_dw_hdmi->hdmi_supply) == -EPROBE_DEFER)
>> - return -EPROBE_DEFER;
>> - meson_dw_hdmi->hdmi_supply = NULL;
>> - } else {
>> - ret = regulator_enable(meson_dw_hdmi->hdmi_supply);
>> - if (ret)
>> - return ret;
>> - ret = devm_add_action_or_reset(dev, meson_disable_regulator,
>> - meson_dw_hdmi->hdmi_supply);
>> - if (ret)
>> - return ret;
>> - }
>> + ret = devm_regulator_get_enable_optional(dev, "hdmi");
>> + if (ret != -ENODEV)
>> + return ret;
>
> As noted in the review of the series that introduced
> devm_regulator_get_enable_optional(), the right thing to do is to
> implement runtime PM in this driver to avoid wasting power.
While I agree, it's not really the same level of effort as this patch
should be functionally equivalent.
>
>>
>> meson_dw_hdmi->hdmitx_apb = devm_reset_control_get_exclusive(dev,
>> "hdmitx_apb");
>
Neil
On 10/21/22 18:29, Neil Armstrong wrote:
> Hi,
>
> On 21/10/2022 17:02, Laurent Pinchart wrote:
>> Hi Matti,
>>
>> On Fri, Oct 21, 2022 at 04:18:01PM +0300, Matti Vaittinen wrote:
>>> Simplify using the devm_regulator_get_enable_optional(). Also drop the
>>> seemingly unused struct member 'hdmi_supply'.
>>>
>>> Signed-off-by: Matti Vaittinen <[email protected]>
>>>
>>> ---
>>> v3 => v4:
>>> - split meson part to own patch
>>>
>>> RFCv1 => v2:
>>> - Change also sii902x to use devm_regulator_bulk_get_enable()
>>>
>>> Please note - this is only compile-tested due to the lack of HW. Careful
>>> review and testing is _highly_ appreciated.
>>> ---
//Snip
>>
>> As noted in the review of the series that introduced
>> devm_regulator_get_enable_optional(), the right thing to do is to
>> implement runtime PM in this driver to avoid wasting power.
>
> While I agree, it's not really the same level of effort as this patch
> should be functionally equivalent.
>
Exactly. As I wrote, I do not have the HW to test this change. This
intends to bring no functional changes. It is just a minor
simplification while also making it harder to create a bug with the
regulator control. (Registering the devm_action and leaving the handle
to the regulator is more fragile than using this new API which does not
give user the handle).
I am in no way against someone further improving the functionality here
(by adding runtime PM) but this someone is not me. Yet, I don't see how
this patch prevents runtime PM being implemented? The first thing that
needs to be done is removing the devm-action assuming someone did
implement power-saving by disabling the regulator(s) at runtime. After
this patch is applied, the action removal is automatically a necessity
in order to get the handle for regulator control.
I know this helper is not preferred by all but it is still safer than
the current code which registers the action while allowing the regulator
control.
Yours
-- Matti
--
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland
~~ When things go utterly wrong vim users can always type :help! ~~
Hi dee Ho Laurent & All,
On 10/21/22 18:29, Neil Armstrong wrote:
> Hi,
>
> On 21/10/2022 17:02, Laurent Pinchart wrote:
>> Hi Matti,
>>
>> On Fri, Oct 21, 2022 at 04:18:01PM +0300, Matti Vaittinen wrote:
>>> Simplify using the devm_regulator_get_enable_optional(). Also drop the
>>> seemingly unused struct member 'hdmi_supply'.
>>>
>>> Signed-off-by: Matti Vaittinen <[email protected]>
>>>
>>> ---
>>> v3 => v4:
>>> - split meson part to own patch
>>>
>>> RFCv1 => v2:
>>> - Change also sii902x to use devm_regulator_bulk_get_enable()
>>>
>>> Please note - this is only compile-tested due to the lack of HW. Careful
>>> review and testing is _highly_ appreciated.
>>> ---
>>> drivers/gpu/drm/meson/meson_dw_hdmi.c | 23 +++--------------------
>>> 1 file changed, 3 insertions(+), 20 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c
>>> b/drivers/gpu/drm/meson/meson_dw_hdmi.c
>>> index 5cd2b2ebbbd3..7642f740272b 100644
>>> --- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
>>> +++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
>>> @@ -140,7 +140,6 @@ struct meson_dw_hdmi {
>>> struct reset_control *hdmitx_apb;
>>> struct reset_control *hdmitx_ctrl;
>>> struct reset_control *hdmitx_phy;
>>> - struct regulator *hdmi_supply;
>>> u32 irq_stat;
>>> struct dw_hdmi *hdmi;
>>> struct drm_bridge *bridge;
>>> @@ -665,11 +664,6 @@ static void meson_dw_hdmi_init(struct
>>> meson_dw_hdmi *meson_dw_hdmi)
>>> }
>>> -static void meson_disable_regulator(void *data)
>>> -{
>>> - regulator_disable(data);
>>> -}
>>> -
>>> static void meson_disable_clk(void *data)
>>> {
>>> clk_disable_unprepare(data);
>>> @@ -723,20 +717,9 @@ static int meson_dw_hdmi_bind(struct device
>>> *dev, struct device *master,
>>> meson_dw_hdmi->data = match;
>>> dw_plat_data = &meson_dw_hdmi->dw_plat_data;
>>> - meson_dw_hdmi->hdmi_supply = devm_regulator_get_optional(dev,
>>> "hdmi");
>>> - if (IS_ERR(meson_dw_hdmi->hdmi_supply)) {
>>> - if (PTR_ERR(meson_dw_hdmi->hdmi_supply) == -EPROBE_DEFER)
>>> - return -EPROBE_DEFER;
>>> - meson_dw_hdmi->hdmi_supply = NULL;
>>> - } else {
>>> - ret = regulator_enable(meson_dw_hdmi->hdmi_supply);
>>> - if (ret)
>>> - return ret;
>>> - ret = devm_add_action_or_reset(dev, meson_disable_regulator,
>>> - meson_dw_hdmi->hdmi_supply);
>>> - if (ret)
>>> - return ret;
>>> - }
>>> + ret = devm_regulator_get_enable_optional(dev, "hdmi");
>>> + if (ret != -ENODEV)
>>> + return ret;
>>
>> As noted in the review of the series that introduced
>> devm_regulator_get_enable_optional(), the right thing to do is to
>> implement runtime PM in this driver to avoid wasting power.
>
> While I agree, it's not really the same level of effort as this patch
> should be functionally equivalent.
While we all agree that power savings gained by runtime PM would be
great - I don't think we should stop minor improvements while waiting
for that to magically happen ;)
I like the saying I first heard from Jonathan Cameron - "Don't let the
perfect be an enemy of good".
After that being said, should I re-spin this or just drop it? (I am
cleaning up my local git from old stuff, and these are about to vanish
from my books).
Yours,
-- Matti
--
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland
~~ When things go utterly wrong vim users can always type :help! ~~
On 16/11/2022 13:02, Vaittinen, Matti wrote:
> Hi dee Ho Laurent & All,
>
> On 10/21/22 18:29, Neil Armstrong wrote:
>> Hi,
>>
>> On 21/10/2022 17:02, Laurent Pinchart wrote:
>>> Hi Matti,
>>>
>>> On Fri, Oct 21, 2022 at 04:18:01PM +0300, Matti Vaittinen wrote:
>>>> Simplify using the devm_regulator_get_enable_optional(). Also drop the
>>>> seemingly unused struct member 'hdmi_supply'.
>>>>
>>>> Signed-off-by: Matti Vaittinen <[email protected]>
>>>>
>>>> ---
>>>> v3 => v4:
>>>> - split meson part to own patch
>>>>
>>>> RFCv1 => v2:
>>>> - Change also sii902x to use devm_regulator_bulk_get_enable()
>>>>
>>>> Please note - this is only compile-tested due to the lack of HW. Careful
>>>> review and testing is _highly_ appreciated.
>>>> ---
>>>> drivers/gpu/drm/meson/meson_dw_hdmi.c | 23 +++--------------------
>>>> 1 file changed, 3 insertions(+), 20 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c
>>>> b/drivers/gpu/drm/meson/meson_dw_hdmi.c
>>>> index 5cd2b2ebbbd3..7642f740272b 100644
>>>> --- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
>>>> +++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
>>>> @@ -140,7 +140,6 @@ struct meson_dw_hdmi {
>>>> struct reset_control *hdmitx_apb;
>>>> struct reset_control *hdmitx_ctrl;
>>>> struct reset_control *hdmitx_phy;
>>>> - struct regulator *hdmi_supply;
>>>> u32 irq_stat;
>>>> struct dw_hdmi *hdmi;
>>>> struct drm_bridge *bridge;
>>>> @@ -665,11 +664,6 @@ static void meson_dw_hdmi_init(struct
>>>> meson_dw_hdmi *meson_dw_hdmi)
>>>> }
>>>> -static void meson_disable_regulator(void *data)
>>>> -{
>>>> - regulator_disable(data);
>>>> -}
>>>> -
>>>> static void meson_disable_clk(void *data)
>>>> {
>>>> clk_disable_unprepare(data);
>>>> @@ -723,20 +717,9 @@ static int meson_dw_hdmi_bind(struct device
>>>> *dev, struct device *master,
>>>> meson_dw_hdmi->data = match;
>>>> dw_plat_data = &meson_dw_hdmi->dw_plat_data;
>>>> - meson_dw_hdmi->hdmi_supply = devm_regulator_get_optional(dev,
>>>> "hdmi");
>>>> - if (IS_ERR(meson_dw_hdmi->hdmi_supply)) {
>>>> - if (PTR_ERR(meson_dw_hdmi->hdmi_supply) == -EPROBE_DEFER)
>>>> - return -EPROBE_DEFER;
>>>> - meson_dw_hdmi->hdmi_supply = NULL;
>>>> - } else {
>>>> - ret = regulator_enable(meson_dw_hdmi->hdmi_supply);
>>>> - if (ret)
>>>> - return ret;
>>>> - ret = devm_add_action_or_reset(dev, meson_disable_regulator,
>>>> - meson_dw_hdmi->hdmi_supply);
>>>> - if (ret)
>>>> - return ret;
>>>> - }
>>>> + ret = devm_regulator_get_enable_optional(dev, "hdmi");
>>>> + if (ret != -ENODEV)
>>>> + return ret;
>>>
>>> As noted in the review of the series that introduced
>>> devm_regulator_get_enable_optional(), the right thing to do is to
>>> implement runtime PM in this driver to avoid wasting power.
>>
>> While I agree, it's not really the same level of effort as this patch
>> should be functionally equivalent.
>
> While we all agree that power savings gained by runtime PM would be
> great - I don't think we should stop minor improvements while waiting
> for that to magically happen ;)
>
> I like the saying I first heard from Jonathan Cameron - "Don't let the
> perfect be an enemy of good".
>
> After that being said, should I re-spin this or just drop it? (I am
> cleaning up my local git from old stuff, and these are about to vanish
> from my books).
I'm ok with you, please re-spin it.
Neil
>
> Yours,
> -- Matti
>