diff mbox

drm/rockchip: vop: Correct enabled clocks during setup

Message ID 1443518893-28142-1-git-send-email-sjoerd.simons@collabora.co.uk (mailing list archive)
State New, archived
Headers show

Commit Message

Sjoerd Simons Sept. 29, 2015, 9:28 a.m. UTC
When doing the initial setup both the hclk and the aclk need to be
enabled otherwise the board will simply hang. This only occurs when
building the vop driver as a module, when its built-in the initial setup
happens to run before the clock framework shuts of unused clocks
(including the aclk).

While there also switch to doing prepare and enable in one step rather
then separate steps to reduce the amount of code required.

Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>

---

 drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 36 +++++++++++------------------
 1 file changed, 14 insertions(+), 22 deletions(-)

Comments

Yakir Yang Sept. 29, 2015, 10:58 a.m. UTC | #1
On 09/29/2015 05:55 PM, Yakir Yang wrote:
>
>
> On 09/29/2015 05:28 PM, Sjoerd Simons wrote:
>> When doing the initial setup both the hclk and the aclk need to be
>> enabled otherwise the board will simply hang. This only occurs when
>> building the vop driver as a module, when its built-in the initial setup

Hmm... My previous test was built-in the vop driver, and just notice that
you say problem only occurred when building the vop driver as module.
That's to say my test was wrong, so I try to do the right things.

But I found that vop driver module and rockchipdrm driver module in
dependency cycles, here are the build message:
     depmod: ERROR: Found 2 modules in dependency cycles!
     depmod: ERROR: Cycle detected: rockchip_drm_vop -> rockchipdrm -> 
rockchip_drm_vop
     Makefile:1054: recipe for target '_modinst_post' failed

And past my Makefile:
vop-y := rockchip_drm_drv.o rockchip_drm_fb.o rockchip_drm_fbdev.o 
rockchip_drm_gem.o
obj-m = rockchip_drm_vop.o vop.o

Very like to know how you handle this dependency cycles :)

Thanks,
- Yakir

>> happens to run before the clock framework shuts of unused clocks
>> (including the aclk).
>>
>> While there also switch to doing prepare and enable in one step rather
>> then separate steps to reduce the amount of code required.
>>
>> Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
>
> Looks good and test on chromeos-3.14 tree, no problem, so
>
> Tested-by: Yakir Yang <ykk@rock-chips.com>
>
>> ---
>>
>>   drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 36 
>> +++++++++++------------------
>>   1 file changed, 14 insertions(+), 22 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c 
>> b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
>> index 5d8ae5e..48719df 100644
>> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
>> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
>> @@ -1575,32 +1575,25 @@ static int vop_initial(struct vop *vop)
>>           return PTR_ERR(vop->dclk);
>>       }
>>   -    ret = clk_prepare(vop->hclk);
>> -    if (ret < 0) {
>> -        dev_err(vop->dev, "failed to prepare hclk\n");
>> -        return ret;
>> -    }
>> -
>>       ret = clk_prepare(vop->dclk);
>>       if (ret < 0) {
>>           dev_err(vop->dev, "failed to prepare dclk\n");
>> -        goto err_unprepare_hclk;
>> +        return ret;
>>       }
>>   -    ret = clk_prepare(vop->aclk);
>> +    /* Enable both the hclk and aclk to setup the vop */
>> +    ret = clk_prepare_enable(vop->hclk);
>>       if (ret < 0) {
>> -        dev_err(vop->dev, "failed to prepare aclk\n");
>> +        dev_err(vop->dev, "failed to prepare/enable hclk\n");
>>           goto err_unprepare_dclk;
>>       }
>>   -    /*
>> -     * enable hclk, so that we can config vop register.
>> -     */
>> -    ret = clk_enable(vop->hclk);
>> +    ret = clk_prepare_enable(vop->aclk);
>>       if (ret < 0) {
>> -        dev_err(vop->dev, "failed to prepare aclk\n");
>> -        goto err_unprepare_aclk;
>> +        dev_err(vop->dev, "failed to prepare/enable aclk\n");
>> +        goto err_disable_hclk;
>>       }
>> +
>>       /*
>>        * do hclk_reset, reset all vop registers.
>>        */
>> @@ -1608,7 +1601,7 @@ static int vop_initial(struct vop *vop)
>>       if (IS_ERR(ahb_rst)) {
>>           dev_err(vop->dev, "failed to get ahb reset\n");
>>           ret = PTR_ERR(ahb_rst);
>> -        goto err_disable_hclk;
>> +        goto err_disable_aclk;
>>       }
>>       reset_control_assert(ahb_rst);
>>       usleep_range(10, 20);
>> @@ -1634,26 +1627,25 @@ static int vop_initial(struct vop *vop)
>>       if (IS_ERR(vop->dclk_rst)) {
>>           dev_err(vop->dev, "failed to get dclk reset\n");
>>           ret = PTR_ERR(vop->dclk_rst);
>> -        goto err_unprepare_aclk;
>> +        goto err_disable_aclk;
>>       }
>>       reset_control_assert(vop->dclk_rst);
>>       usleep_range(10, 20);
>>       reset_control_deassert(vop->dclk_rst);
>>         clk_disable(vop->hclk);
>> +    clk_disable(vop->aclk);
>>         vop->is_enabled = false;
>>         return 0;
>>   +err_disable_aclk:
>> +    clk_disable_unprepare(vop->aclk);
>>   err_disable_hclk:
>> -    clk_disable(vop->hclk);
>> -err_unprepare_aclk:
>> -    clk_unprepare(vop->aclk);
>> +    clk_disable_unprepare(vop->hclk);
>>   err_unprepare_dclk:
>>       clk_unprepare(vop->dclk);
>> -err_unprepare_hclk:
>> -    clk_unprepare(vop->hclk);
>>       return ret;
>>   }
>
Sjoerd Simons Sept. 29, 2015, 11:58 a.m. UTC | #2
On Tue, 2015-09-29 at 18:58 +0800, Yakir Yang wrote:
> 
> On 09/29/2015 05:55 PM, Yakir Yang wrote:
> > 
> > 
> > On 09/29/2015 05:28 PM, Sjoerd Simons wrote:
> > > When doing the initial setup both the hclk and the aclk need to
> > > be
> > > enabled otherwise the board will simply hang. This only occurs
> > > when
> > > building the vop driver as a module, when its built-in the
> > > initial setup
> 
> Hmm... My previous test was built-in the vop driver, and just notice
> that
> you say problem only occurred when building the vop driver as module.
> That's to say my test was wrong, so I try to do the right things.
> 
> But I found that vop driver module and rockchipdrm driver module in
> dependency cycles, here are the build message:
>      depmod: ERROR: Found 2 modules in dependency cycles!


I've only tested with mainline which doesn't seem to have that issue?
So can't easily help you there unfortunately.


> Thanks,
> - Yakir
> 
> > > happens to run before the clock framework shuts of unused clocks
> > > (including the aclk).
> > > 
> > > While there also switch to doing prepare and enable in one step
> > > rather
> > > then separate steps to reduce the amount of code required.
> > > 
> > > Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
> > 
> > Looks good and test on chromeos-3.14 tree, no problem, so
> > 
> > Tested-by: Yakir Yang <ykk@rock-chips.com>
> > 
> > > ---
> > > 
> > >   drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 36 
> > > +++++++++++------------------
> > >   1 file changed, 14 insertions(+), 22 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c 
> > > b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> > > index 5d8ae5e..48719df 100644
> > > --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> > > +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> > > @@ -1575,32 +1575,25 @@ static int vop_initial(struct vop *vop)
> > >           return PTR_ERR(vop->dclk);
> > >       }
> > >   -    ret = clk_prepare(vop->hclk);
> > > -    if (ret < 0) {
> > > -        dev_err(vop->dev, "failed to prepare hclk\n");
> > > -        return ret;
> > > -    }
> > > -
> > >       ret = clk_prepare(vop->dclk);
> > >       if (ret < 0) {
> > >           dev_err(vop->dev, "failed to prepare dclk\n");
> > > -        goto err_unprepare_hclk;
> > > +        return ret;
> > >       }
> > >   -    ret = clk_prepare(vop->aclk);
> > > +    /* Enable both the hclk and aclk to setup the vop */
> > > +    ret = clk_prepare_enable(vop->hclk);
> > >       if (ret < 0) {
> > > -        dev_err(vop->dev, "failed to prepare aclk\n");
> > > +        dev_err(vop->dev, "failed to prepare/enable hclk\n");
> > >           goto err_unprepare_dclk;
> > >       }
> > >   -    /*
> > > -     * enable hclk, so that we can config vop register.
> > > -     */
> > > -    ret = clk_enable(vop->hclk);
> > > +    ret = clk_prepare_enable(vop->aclk);
> > >       if (ret < 0) {
> > > -        dev_err(vop->dev, "failed to prepare aclk\n");
> > > -        goto err_unprepare_aclk;
> > > +        dev_err(vop->dev, "failed to prepare/enable aclk\n");
> > > +        goto err_disable_hclk;
> > >       }
> > > +
> > >       /*
> > >        * do hclk_reset, reset all vop registers.
> > >        */
> > > @@ -1608,7 +1601,7 @@ static int vop_initial(struct vop *vop)
> > >       if (IS_ERR(ahb_rst)) {
> > >           dev_err(vop->dev, "failed to get ahb reset\n");
> > >           ret = PTR_ERR(ahb_rst);
> > > -        goto err_disable_hclk;
> > > +        goto err_disable_aclk;
> > >       }
> > >       reset_control_assert(ahb_rst);
> > >       usleep_range(10, 20);
> > > @@ -1634,26 +1627,25 @@ static int vop_initial(struct vop *vop)
> > >       if (IS_ERR(vop->dclk_rst)) {
> > >           dev_err(vop->dev, "failed to get dclk reset\n");
> > >           ret = PTR_ERR(vop->dclk_rst);
> > > -        goto err_unprepare_aclk;
> > > +        goto err_disable_aclk;
> > >       }
> > >       reset_control_assert(vop->dclk_rst);
> > >       usleep_range(10, 20);
> > >       reset_control_deassert(vop->dclk_rst);
> > >         clk_disable(vop->hclk);
> > > +    clk_disable(vop->aclk);
> > >         vop->is_enabled = false;
> > >         return 0;
> > >   +err_disable_aclk:
> > > +    clk_disable_unprepare(vop->aclk);
> > >   err_disable_hclk:
> > > -    clk_disable(vop->hclk);
> > > -err_unprepare_aclk:
> > > -    clk_unprepare(vop->aclk);
> > > +    clk_disable_unprepare(vop->hclk);
> > >   err_unprepare_dclk:
> > >       clk_unprepare(vop->dclk);
> > > -err_unprepare_hclk:
> > > -    clk_unprepare(vop->hclk);
> > >       return ret;
> > >   }
> > 
> 
>
Romain Perier Sept. 30, 2015, 9:51 a.m. UTC | #3
Hi all,

I had an issue with the drm driver, when I start the kernel via kexec,
the drm driver freezes the platform. it is caused by the function
vop_initial (when copying registers via ahb). This issue happens with
the chromeos kernel or with the mainline kernel. When I investigated a
bit, I found that it had something to do with the hclk clock.

This patch fixes the issue. Everything works like a charm now.

Tested-by: Romain Perier <romain.perier@gmail.com>

2015-09-29 13:58 GMT+02:00 Sjoerd Simons <sjoerd.simons@collabora.co.uk>:
> On Tue, 2015-09-29 at 18:58 +0800, Yakir Yang wrote:
>>
>> On 09/29/2015 05:55 PM, Yakir Yang wrote:
>> >
>> >
>> > On 09/29/2015 05:28 PM, Sjoerd Simons wrote:
>> > > When doing the initial setup both the hclk and the aclk need to
>> > > be
>> > > enabled otherwise the board will simply hang. This only occurs
>> > > when
>> > > building the vop driver as a module, when its built-in the
>> > > initial setup
>>
>> Hmm... My previous test was built-in the vop driver, and just notice
>> that
>> you say problem only occurred when building the vop driver as module.
>> That's to say my test was wrong, so I try to do the right things.
>>
>> But I found that vop driver module and rockchipdrm driver module in
>> dependency cycles, here are the build message:
>>      depmod: ERROR: Found 2 modules in dependency cycles!
>
>
> I've only tested with mainline which doesn't seem to have that issue?
> So can't easily help you there unfortunately.
>
>
>> Thanks,
>> - Yakir
>>
>> > > happens to run before the clock framework shuts of unused clocks
>> > > (including the aclk).
>> > >
>> > > While there also switch to doing prepare and enable in one step
>> > > rather
>> > > then separate steps to reduce the amount of code required.
>> > >
>> > > Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
>> >
>> > Looks good and test on chromeos-3.14 tree, no problem, so
>> >
>> > Tested-by: Yakir Yang <ykk@rock-chips.com>
>> >
>> > > ---
>> > >
>> > >   drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 36
>> > > +++++++++++------------------
>> > >   1 file changed, 14 insertions(+), 22 deletions(-)
>> > >
>> > > diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
>> > > b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
>> > > index 5d8ae5e..48719df 100644
>> > > --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
>> > > +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
>> > > @@ -1575,32 +1575,25 @@ static int vop_initial(struct vop *vop)
>> > >           return PTR_ERR(vop->dclk);
>> > >       }
>> > >   -    ret = clk_prepare(vop->hclk);
>> > > -    if (ret < 0) {
>> > > -        dev_err(vop->dev, "failed to prepare hclk\n");
>> > > -        return ret;
>> > > -    }
>> > > -
>> > >       ret = clk_prepare(vop->dclk);
>> > >       if (ret < 0) {
>> > >           dev_err(vop->dev, "failed to prepare dclk\n");
>> > > -        goto err_unprepare_hclk;
>> > > +        return ret;
>> > >       }
>> > >   -    ret = clk_prepare(vop->aclk);
>> > > +    /* Enable both the hclk and aclk to setup the vop */
>> > > +    ret = clk_prepare_enable(vop->hclk);
>> > >       if (ret < 0) {
>> > > -        dev_err(vop->dev, "failed to prepare aclk\n");
>> > > +        dev_err(vop->dev, "failed to prepare/enable hclk\n");
>> > >           goto err_unprepare_dclk;
>> > >       }
>> > >   -    /*
>> > > -     * enable hclk, so that we can config vop register.
>> > > -     */
>> > > -    ret = clk_enable(vop->hclk);
>> > > +    ret = clk_prepare_enable(vop->aclk);
>> > >       if (ret < 0) {
>> > > -        dev_err(vop->dev, "failed to prepare aclk\n");
>> > > -        goto err_unprepare_aclk;
>> > > +        dev_err(vop->dev, "failed to prepare/enable aclk\n");
>> > > +        goto err_disable_hclk;
>> > >       }
>> > > +
>> > >       /*
>> > >        * do hclk_reset, reset all vop registers.
>> > >        */
>> > > @@ -1608,7 +1601,7 @@ static int vop_initial(struct vop *vop)
>> > >       if (IS_ERR(ahb_rst)) {
>> > >           dev_err(vop->dev, "failed to get ahb reset\n");
>> > >           ret = PTR_ERR(ahb_rst);
>> > > -        goto err_disable_hclk;
>> > > +        goto err_disable_aclk;
>> > >       }
>> > >       reset_control_assert(ahb_rst);
>> > >       usleep_range(10, 20);
>> > > @@ -1634,26 +1627,25 @@ static int vop_initial(struct vop *vop)
>> > >       if (IS_ERR(vop->dclk_rst)) {
>> > >           dev_err(vop->dev, "failed to get dclk reset\n");
>> > >           ret = PTR_ERR(vop->dclk_rst);
>> > > -        goto err_unprepare_aclk;
>> > > +        goto err_disable_aclk;
>> > >       }
>> > >       reset_control_assert(vop->dclk_rst);
>> > >       usleep_range(10, 20);
>> > >       reset_control_deassert(vop->dclk_rst);
>> > >         clk_disable(vop->hclk);
>> > > +    clk_disable(vop->aclk);
>> > >         vop->is_enabled = false;
>> > >         return 0;
>> > >   +err_disable_aclk:
>> > > +    clk_disable_unprepare(vop->aclk);
>> > >   err_disable_hclk:
>> > > -    clk_disable(vop->hclk);
>> > > -err_unprepare_aclk:
>> > > -    clk_unprepare(vop->aclk);
>> > > +    clk_disable_unprepare(vop->hclk);
>> > >   err_unprepare_dclk:
>> > >       clk_unprepare(vop->dclk);
>> > > -err_unprepare_hclk:
>> > > -    clk_unprepare(vop->hclk);
>> > >       return ret;
>> > >   }
>> >
>>
>>
>
> --
> Sjoerd Simons
> Collabora Ltd.
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff mbox

Patch

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index 5d8ae5e..48719df 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -1575,32 +1575,25 @@  static int vop_initial(struct vop *vop)
 		return PTR_ERR(vop->dclk);
 	}
 
-	ret = clk_prepare(vop->hclk);
-	if (ret < 0) {
-		dev_err(vop->dev, "failed to prepare hclk\n");
-		return ret;
-	}
-
 	ret = clk_prepare(vop->dclk);
 	if (ret < 0) {
 		dev_err(vop->dev, "failed to prepare dclk\n");
-		goto err_unprepare_hclk;
+		return ret;
 	}
 
-	ret = clk_prepare(vop->aclk);
+	/* Enable both the hclk and aclk to setup the vop */
+	ret = clk_prepare_enable(vop->hclk);
 	if (ret < 0) {
-		dev_err(vop->dev, "failed to prepare aclk\n");
+		dev_err(vop->dev, "failed to prepare/enable hclk\n");
 		goto err_unprepare_dclk;
 	}
 
-	/*
-	 * enable hclk, so that we can config vop register.
-	 */
-	ret = clk_enable(vop->hclk);
+	ret = clk_prepare_enable(vop->aclk);
 	if (ret < 0) {
-		dev_err(vop->dev, "failed to prepare aclk\n");
-		goto err_unprepare_aclk;
+		dev_err(vop->dev, "failed to prepare/enable aclk\n");
+		goto err_disable_hclk;
 	}
+
 	/*
 	 * do hclk_reset, reset all vop registers.
 	 */
@@ -1608,7 +1601,7 @@  static int vop_initial(struct vop *vop)
 	if (IS_ERR(ahb_rst)) {
 		dev_err(vop->dev, "failed to get ahb reset\n");
 		ret = PTR_ERR(ahb_rst);
-		goto err_disable_hclk;
+		goto err_disable_aclk;
 	}
 	reset_control_assert(ahb_rst);
 	usleep_range(10, 20);
@@ -1634,26 +1627,25 @@  static int vop_initial(struct vop *vop)
 	if (IS_ERR(vop->dclk_rst)) {
 		dev_err(vop->dev, "failed to get dclk reset\n");
 		ret = PTR_ERR(vop->dclk_rst);
-		goto err_unprepare_aclk;
+		goto err_disable_aclk;
 	}
 	reset_control_assert(vop->dclk_rst);
 	usleep_range(10, 20);
 	reset_control_deassert(vop->dclk_rst);
 
 	clk_disable(vop->hclk);
+	clk_disable(vop->aclk);
 
 	vop->is_enabled = false;
 
 	return 0;
 
+err_disable_aclk:
+	clk_disable_unprepare(vop->aclk);
 err_disable_hclk:
-	clk_disable(vop->hclk);
-err_unprepare_aclk:
-	clk_unprepare(vop->aclk);
+	clk_disable_unprepare(vop->hclk);
 err_unprepare_dclk:
 	clk_unprepare(vop->dclk);
-err_unprepare_hclk:
-	clk_unprepare(vop->hclk);
 	return ret;
 }