[PATCH 1/4] drm/dp: add flags field to drm_dp_aux_msg struct

[Alex Deucher]

On Fri, Apr 4, 2014 at 2:09 AM, Jani Nikula  
wrote:
> On Sat, 22 Mar 2014, Alex Deucher  wrote:
>> This adds a flags field and a new flag, BARE_ADDRESS,
>> which drivers can use for special handling when they
>> want to set just the aux address.  This is needed
>> to properly reset the connection between i2c transactions.
>
> Sorry it took me so long to get to this.
>
> The changes in patches 1-3 look sensible in general, but I think I'd
> prefer you dropped the flags field and used size == 0 to mean bare
> address. It feels silly to have to set size = 1 and have a dummy one
> byte buffer that doesn't get transfered. Without the payload I think it
> feels natural only the address is transfered.

Thanks.  I'll resend with size = 0.  Note that it doesn't look like
the current intel dp code handles zero sized transfers so that will
need to be fixed up.

Alex


>
> BR,
> Jani.
>
>
>>
>> Signed-off-by: Alex Deucher 
>> ---
>>  include/drm/drm_dp_helper.h | 3 +++
>>  1 file changed, 3 insertions(+)
>>
>> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
>> index b7488c9..a006e96 100644
>> --- a/include/drm/drm_dp_helper.h
>> +++ b/include/drm/drm_dp_helper.h
>> @@ -403,6 +403,8 @@ drm_dp_enhanced_frame_cap(const u8 
>> dpcd[DP_RECEIVER_CAP_SIZE])
>>   * DisplayPort AUX channel
>>   */
>>
>> +#define DRM_DP_AUX_MSG_FLAGS_BARE_ADDRESS (1 << 0)
>> +
>>  /**
>>   * struct drm_dp_aux_msg - DisplayPort AUX channel transaction
>>   * @address: address of the (first) register to access
>> @@ -417,6 +419,7 @@ struct drm_dp_aux_msg {
>>   u8 reply;
>>   void *buffer;
>>   size_t size;
>> + u32 flags;
>>  };
>>
>>  /**
>> --
>> 1.8.3.1
>>
>> ___
>> dri-devel mailing list
>> dri-devel at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/dri-devel
>
> --
> Jani Nikula, Intel Open Source Technology Center

[PATCH 1/4] drm/dp: add flags field to drm_dp_aux_msg struct

[Jani Nikula]

On Sat, 22 Mar 2014, Alex Deucher  wrote:
> This adds a flags field and a new flag, BARE_ADDRESS,
> which drivers can use for special handling when they
> want to set just the aux address.  This is needed
> to properly reset the connection between i2c transactions.

Sorry it took me so long to get to this.

The changes in patches 1-3 look sensible in general, but I think I'd
prefer you dropped the flags field and used size == 0 to mean bare
address. It feels silly to have to set size = 1 and have a dummy one
byte buffer that doesn't get transfered. Without the payload I think it
feels natural only the address is transfered.

BR,
Jani.


>
> Signed-off-by: Alex Deucher 
> ---
>  include/drm/drm_dp_helper.h | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
> index b7488c9..a006e96 100644
> --- a/include/drm/drm_dp_helper.h
> +++ b/include/drm/drm_dp_helper.h
> @@ -403,6 +403,8 @@ drm_dp_enhanced_frame_cap(const u8 
> dpcd[DP_RECEIVER_CAP_SIZE])
>   * DisplayPort AUX channel
>   */
>  
> +#define DRM_DP_AUX_MSG_FLAGS_BARE_ADDRESS (1 << 0)
> +
>  /**
>   * struct drm_dp_aux_msg - DisplayPort AUX channel transaction
>   * @address: address of the (first) register to access
> @@ -417,6 +419,7 @@ struct drm_dp_aux_msg {
>   u8 reply;
>   void *buffer;
>   size_t size;
> + u32 flags;
>  };
>  
>  /**
> -- 
> 1.8.3.1
>
> ___
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Jani Nikula, Intel Open Source Technology Center

[PATCH 1/4] drm/dp: add flags field to drm_dp_aux_msg struct

[Alex Deucher]

This adds a flags field and a new flag, BARE_ADDRESS,
which drivers can use for special handling when they
want to set just the aux address.  This is needed
to properly reset the connection between i2c transactions.

Signed-off-by: Alex Deucher 
---
 include/drm/drm_dp_helper.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index b7488c9..a006e96 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -403,6 +403,8 @@ drm_dp_enhanced_frame_cap(const u8 
dpcd[DP_RECEIVER_CAP_SIZE])
  * DisplayPort AUX channel
  */

+#define DRM_DP_AUX_MSG_FLAGS_BARE_ADDRESS (1 << 0)
+
 /**
  * struct drm_dp_aux_msg - DisplayPort AUX channel transaction
  * @address: address of the (first) register to access
@@ -417,6 +419,7 @@ struct drm_dp_aux_msg {
u8 reply;
void *buffer;
size_t size;
+   u32 flags;
 };

 /**
-- 
1.8.3.1