* [PATCH] drm/radeon: warn users when hw_i2c is enabled
@ 2014-01-07 15:14 Alex Deucher
2014-01-07 15:16 ` Christian König
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Alex Deucher @ 2014-01-07 15:14 UTC (permalink / raw)
To: dri-devel; +Cc: Alex Deucher, stable
The hw i2c engines are disabled by default as the
current implementation is still experimental. Print
a warning when users enable it so that it's obvious
when the option is enabled.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
---
drivers/gpu/drm/radeon/radeon_i2c.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/radeon/radeon_i2c.c b/drivers/gpu/drm/radeon/radeon_i2c.c
index fc60b74..74bfbf8 100644
--- a/drivers/gpu/drm/radeon/radeon_i2c.c
+++ b/drivers/gpu/drm/radeon/radeon_i2c.c
@@ -1020,6 +1020,9 @@ void radeon_i2c_destroy(struct radeon_i2c_chan *i2c)
/* Add the default buses */
void radeon_i2c_init(struct radeon_device *rdev)
{
+ if (radeon_hw_i2c == 1)
+ DRM_INFO("hw_i2c forced on, you may experience display detection problems!\n");
+
if (rdev->is_atom_bios)
radeon_atombios_i2c_init(rdev);
else
--
1.8.3.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] drm/radeon: warn users when hw_i2c is enabled
2014-01-07 15:14 [PATCH] drm/radeon: warn users when hw_i2c is enabled Alex Deucher
@ 2014-01-07 15:16 ` Christian König
2014-01-07 15:58 ` Grigori Goronzy
2014-01-07 16:16 ` Rafał Miłecki
2 siblings, 0 replies; 6+ messages in thread
From: Christian König @ 2014-01-07 15:16 UTC (permalink / raw)
To: Alex Deucher, dri-devel; +Cc: Alex Deucher, stable
Am 07.01.2014 16:14, schrieb Alex Deucher:
> The hw i2c engines are disabled by default as the
> current implementation is still experimental. Print
> a warning when users enable it so that it's obvious
> when the option is enabled.
>
> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
> Cc: stable@vger.kernel.org
Reviewed-by: Christian König <christian.koenig@amd.com>
> ---
> drivers/gpu/drm/radeon/radeon_i2c.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_i2c.c b/drivers/gpu/drm/radeon/radeon_i2c.c
> index fc60b74..74bfbf8 100644
> --- a/drivers/gpu/drm/radeon/radeon_i2c.c
> +++ b/drivers/gpu/drm/radeon/radeon_i2c.c
> @@ -1020,6 +1020,9 @@ void radeon_i2c_destroy(struct radeon_i2c_chan *i2c)
> /* Add the default buses */
> void radeon_i2c_init(struct radeon_device *rdev)
> {
> + if (radeon_hw_i2c == 1)
> + DRM_INFO("hw_i2c forced on, you may experience display detection problems!\n");
> +
> if (rdev->is_atom_bios)
> radeon_atombios_i2c_init(rdev);
> else
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] drm/radeon: warn users when hw_i2c is enabled
2014-01-07 15:14 [PATCH] drm/radeon: warn users when hw_i2c is enabled Alex Deucher
2014-01-07 15:16 ` Christian König
@ 2014-01-07 15:58 ` Grigori Goronzy
2014-01-07 16:02 ` Alex Deucher
2014-01-07 16:16 ` Rafał Miłecki
2 siblings, 1 reply; 6+ messages in thread
From: Grigori Goronzy @ 2014-01-07 15:58 UTC (permalink / raw)
To: Alex Deucher, dri-devel; +Cc: Alex Deucher, stable
On 07.01.2014 16:14, Alex Deucher wrote:
> The hw i2c engines are disabled by default as the
> current implementation is still experimental. Print
> a warning when users enable it so that it's obvious
> when the option is enabled.
>
Does hardware I2C actually have any advantage in the DDC use case?
AFAICT it's only transferring small amounts of data and mostly on
display connect events, so not very often.
Best regards
Grigori
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] drm/radeon: warn users when hw_i2c is enabled
2014-01-07 15:58 ` Grigori Goronzy
@ 2014-01-07 16:02 ` Alex Deucher
0 siblings, 0 replies; 6+ messages in thread
From: Alex Deucher @ 2014-01-07 16:02 UTC (permalink / raw)
To: Grigori Goronzy; +Cc: Maling list - DRI developers, Alex Deucher, for 3.8
On Tue, Jan 7, 2014 at 10:58 AM, Grigori Goronzy <greg@chown.ath.cx> wrote:
> On 07.01.2014 16:14, Alex Deucher wrote:
>>
>> The hw i2c engines are disabled by default as the
>> current implementation is still experimental. Print
>> a warning when users enable it so that it's obvious
>> when the option is enabled.
>>
>
> Does hardware I2C actually have any advantage in the DDC use case? AFAICT
> it's only transferring small amounts of data and mostly on display connect
> events, so not very often.
It's lower CPU usage compared to bit-banging and can generate
interrupts if you want to do something else while it fetches the EDID.
Alex
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] drm/radeon: warn users when hw_i2c is enabled
2014-01-07 15:14 [PATCH] drm/radeon: warn users when hw_i2c is enabled Alex Deucher
2014-01-07 15:16 ` Christian König
2014-01-07 15:58 ` Grigori Goronzy
@ 2014-01-07 16:16 ` Rafał Miłecki
2014-01-07 16:46 ` Alex Deucher
2 siblings, 1 reply; 6+ messages in thread
From: Rafał Miłecki @ 2014-01-07 16:16 UTC (permalink / raw)
To: Alex Deucher; +Cc: dri-devel, Alex Deucher, Stable
2014/1/7 Alex Deucher <alexdeucher@gmail.com>:
> + if (radeon_hw_i2c == 1)
> + DRM_INFO("hw_i2c forced on, you may experience display detection problems!\n");
What about simple
if (radeon_hw_i2c)
? Values 2, 3, ... also enable i2c.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] drm/radeon: warn users when hw_i2c is enabled
2014-01-07 16:16 ` Rafał Miłecki
@ 2014-01-07 16:46 ` Alex Deucher
0 siblings, 0 replies; 6+ messages in thread
From: Alex Deucher @ 2014-01-07 16:46 UTC (permalink / raw)
To: Rafał Miłecki; +Cc: dri-devel, Alex Deucher, Stable
On Tue, Jan 7, 2014 at 11:16 AM, Rafał Miłecki <zajec5@gmail.com> wrote:
> 2014/1/7 Alex Deucher <alexdeucher@gmail.com>:
>> + if (radeon_hw_i2c == 1)
>> + DRM_INFO("hw_i2c forced on, you may experience display detection problems!\n");
>
> What about simple
> if (radeon_hw_i2c)
> ? Values 2, 3, ... also enable i2c.
Updated patch sent. thanks!
Alex
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2014-01-07 16:46 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2014-01-07 15:14 [PATCH] drm/radeon: warn users when hw_i2c is enabled Alex Deucher
2014-01-07 15:16 ` Christian König
2014-01-07 15:58 ` Grigori Goronzy
2014-01-07 16:02 ` Alex Deucher
2014-01-07 16:16 ` Rafał Miłecki
2014-01-07 16:46 ` Alex Deucher
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