[PATCH 1/3] drm/dp: WARN about invalid/unknown link rates and bw codes

[Jani Nikula]

On Mon, 09 Oct 2017, Thierry Reding <treding at nvidia.com> wrote:
> On Mon, Oct 09, 2017 at 12:29:57PM +0300, Jani Nikula wrote:
>> Falling back to the lowest value is likely the only thing we can do, but
>> doing it silently seems like a bad thing to do. Catch it early and make
>> loud noises.
>> 
>> Cc: Alex Deucher <alexander.deucher at amd.com>
>> Cc: Thierry Reding <treding at nvidia.com>
>> Cc: Rob Clark <robdclark at gmail.com>
>> Cc: Sean Paul <seanpaul at chromium.org>
>> Cc: Manasi Navare <manasi.d.navare at intel.com>
>> Cc: dri-devel at lists.freedesktop.org
>> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
>> ---
>>  drivers/gpu/drm/drm_dp_helper.c | 7 +++++--
>>  1 file changed, 5 insertions(+), 2 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
>> index 08af8d6b844b..dca21b5a03ec 100644
>> --- a/drivers/gpu/drm/drm_dp_helper.c
>> +++ b/drivers/gpu/drm/drm_dp_helper.c
>> @@ -137,8 +137,10 @@ EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay);
>>  u8 drm_dp_link_rate_to_bw_code(int link_rate)
>>  {
>>  	switch (link_rate) {
>> -	case 162000:
>>  	default:
>> +		WARN(1, "unknown DP link rate %d, using %x\n", link_rate,
>> +		     DP_LINK_BW_1_62);
>> +	case 162000:
>>  		return DP_LINK_BW_1_62;
>>  	case 270000:
>>  		return DP_LINK_BW_2_7;
>> @@ -151,8 +153,9 @@ EXPORT_SYMBOL(drm_dp_link_rate_to_bw_code);
>>  int drm_dp_bw_code_to_link_rate(u8 link_bw)
>>  {
>>  	switch (link_bw) {
>> -	case DP_LINK_BW_1_62:
>>  	default:
>> +		WARN(1, "unknown DP link bw code %x, using 162000\n", link_bw);
>
> Nit: "DP link BW" because it is an abbreviation. Otherwise looks good:

Thanks for the reviews everyone, pushed patch 1 with BW upcased to
drm-misc-next.

BR,
Jani.

>
> Reviewed-by: Thierry Reding <treding at nvidia.com>

-- 
Jani Nikula, Intel Open Source Technology Center