[03/10] drm/msm/dsi: Zero-terminate msm_dsi_config::io_start

Message ID 20230211115110.1462920-4-konrad.dybcio@linaro.org
State New
Headers
Series [01/10] dt-bindings: display/msm: dsi-controller-main: Fix deprecated QCM2290 compatible |

Commit Message

Konrad Dybcio Feb. 11, 2023, 11:51 a.m. UTC
  In preparation for supporting multiple sets of possible base registers,
Zero-terminate the array that contains them to remove the need of
specifying num_dsi for each set.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
---
 drivers/gpu/drm/msm/dsi/dsi_cfg.c  | 39 ++++++++++--------------------
 drivers/gpu/drm/msm/dsi/dsi_cfg.h  |  4 +--
 drivers/gpu/drm/msm/dsi/dsi_host.c |  2 +-
 3 files changed, 16 insertions(+), 29 deletions(-)
  

Comments

Dmitry Baryshkov Feb. 11, 2023, 1:19 p.m. UTC | #1
On 11/02/2023 13:51, Konrad Dybcio wrote:
> In preparation for supporting multiple sets of possible base registers,
> Zero-terminate the array that contains them to remove the need of
> specifying num_dsi for each set.
> 
> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> ---
>   drivers/gpu/drm/msm/dsi/dsi_cfg.c  | 39 ++++++++++--------------------
>   drivers/gpu/drm/msm/dsi/dsi_cfg.h  |  4 +--
>   drivers/gpu/drm/msm/dsi/dsi_host.c |  2 +-
>   3 files changed, 16 insertions(+), 29 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_cfg.c b/drivers/gpu/drm/msm/dsi/dsi_cfg.c
> index 068d45b3a8f0..5f62c563bd1c 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_cfg.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_cfg.c
> @@ -22,9 +22,8 @@ static const struct msm_dsi_config apq8064_dsi_cfg = {
>   	.bus_clk_names = dsi_v2_bus_clk_names,
>   	.num_bus_clks = ARRAY_SIZE(dsi_v2_bus_clk_names),
>   	.io_start = {
> -		{ 0x4700000, 0x5800000 },
> +		{ 0x4700000, 0x5800000, 0 },
>   	},
> -	.num_dsi = 2,
>   };
>   
>   static const char * const dsi_6g_bus_clk_names[] = {
> @@ -44,9 +43,8 @@ static const struct msm_dsi_config msm8974_apq8084_dsi_cfg = {
>   	.bus_clk_names = dsi_6g_bus_clk_names,
>   	.num_bus_clks = ARRAY_SIZE(dsi_6g_bus_clk_names),
>   	.io_start = {
> -		{ 0xfd922800, 0xfd922b00 },
> +		{ 0xfd922800, 0xfd922b00, 0 },
>   	},
> -	.num_dsi = 2,
>   };
>   
>   static const char * const dsi_8916_bus_clk_names[] = {
> @@ -65,9 +63,8 @@ static const struct msm_dsi_config msm8916_dsi_cfg = {
>   	.bus_clk_names = dsi_8916_bus_clk_names,
>   	.num_bus_clks = ARRAY_SIZE(dsi_8916_bus_clk_names),
>   	.io_start = {
> -		{ 0x1a98000 },
> +		{ 0x1a98000, 0 },
>   	},
> -	.num_dsi = 1,
>   };
>   
>   static const char * const dsi_8976_bus_clk_names[] = {
> @@ -86,9 +83,8 @@ static const struct msm_dsi_config msm8976_dsi_cfg = {
>   	.bus_clk_names = dsi_8976_bus_clk_names,
>   	.num_bus_clks = ARRAY_SIZE(dsi_8976_bus_clk_names),
>   	.io_start = {
> -		{ 0x1a94000, 0x1a96000 },
> +		{ 0x1a94000, 0x1a96000, 0 },
>   	},
> -	.num_dsi = 2,
>   };
>   
>   static const struct regulator_bulk_data msm8994_dsi_regulators[] = {
> @@ -107,9 +103,8 @@ static const struct msm_dsi_config msm8994_dsi_cfg = {
>   	.bus_clk_names = dsi_6g_bus_clk_names,
>   	.num_bus_clks = ARRAY_SIZE(dsi_6g_bus_clk_names),
>   	.io_start = {
> -		{ 0xfd998000, 0xfd9a0000 },
> +		{ 0xfd998000, 0xfd9a0000, 0 },
>   	},
> -	.num_dsi = 2,
>   };
>   
>   static const char * const dsi_8996_bus_clk_names[] = {
> @@ -129,9 +124,8 @@ static const struct msm_dsi_config msm8996_dsi_cfg = {
>   	.bus_clk_names = dsi_8996_bus_clk_names,
>   	.num_bus_clks = ARRAY_SIZE(dsi_8996_bus_clk_names),
>   	.io_start = {
> -		{ 0x994000, 0x996000 },
> +		{ 0x994000, 0x996000, 0 },
>   	},
> -	.num_dsi = 2,
>   };
>   
>   static const char * const dsi_msm8998_bus_clk_names[] = {
> @@ -150,9 +144,8 @@ static const struct msm_dsi_config msm8998_dsi_cfg = {
>   	.bus_clk_names = dsi_msm8998_bus_clk_names,
>   	.num_bus_clks = ARRAY_SIZE(dsi_msm8998_bus_clk_names),
>   	.io_start = {
> -		{ 0xc994000, 0xc996000 },
> +		{ 0xc994000, 0xc996000, 0 },
>   	},
> -	.num_dsi = 2,
>   };
>   
>   static const char * const dsi_sdm660_bus_clk_names[] = {
> @@ -170,9 +163,8 @@ static const struct msm_dsi_config sdm660_dsi_cfg = {
>   	.bus_clk_names = dsi_sdm660_bus_clk_names,
>   	.num_bus_clks = ARRAY_SIZE(dsi_sdm660_bus_clk_names),
>   	.io_start = {
> -		{ 0xc994000, 0xc996000 },
> +		{ 0xc994000, 0xc996000, 0 },
>   	},
> -	.num_dsi = 2,
>   };
>   
>   static const char * const dsi_sdm845_bus_clk_names[] = {
> @@ -194,9 +186,8 @@ static const struct msm_dsi_config sdm845_dsi_cfg = {
>   	.bus_clk_names = dsi_sdm845_bus_clk_names,
>   	.num_bus_clks = ARRAY_SIZE(dsi_sdm845_bus_clk_names),
>   	.io_start = {
> -		{ 0xae94000, 0xae96000 },
> +		{ 0xae94000, 0xae96000, 0 },
>   	},
> -	.num_dsi = 2,
>   };
>   
>   static const struct regulator_bulk_data sm8550_dsi_regulators[] = {
> @@ -210,9 +201,8 @@ static const struct msm_dsi_config sm8550_dsi_cfg = {
>   	.bus_clk_names = dsi_sdm845_bus_clk_names,
>   	.num_bus_clks = ARRAY_SIZE(dsi_sdm845_bus_clk_names),
>   	.io_start = {
> -		{ 0xae94000, 0xae96000 },
> +		{ 0xae94000, 0xae96000, 0 },
>   	},
> -	.num_dsi = 2,
>   };
>   
>   static const struct regulator_bulk_data sc7180_dsi_regulators[] = {
> @@ -226,9 +216,8 @@ static const struct msm_dsi_config sc7180_dsi_cfg = {
>   	.bus_clk_names = dsi_sc7180_bus_clk_names,
>   	.num_bus_clks = ARRAY_SIZE(dsi_sc7180_bus_clk_names),
>   	.io_start = {
> -		{ 0xae94000 },
> +		{ 0xae94000, 0 },
>   	},
> -	.num_dsi = 1,
>   };
>   
>   static const char * const dsi_sc7280_bus_clk_names[] = {
> @@ -246,9 +235,8 @@ static const struct msm_dsi_config sc7280_dsi_cfg = {
>   	.bus_clk_names = dsi_sc7280_bus_clk_names,
>   	.num_bus_clks = ARRAY_SIZE(dsi_sc7280_bus_clk_names),
>   	.io_start = {
> -		{ 0xae94000, 0xae96000 },
> +		{ 0xae94000, 0xae96000, 0 },
>   	},
> -	.num_dsi = 2,
>   };
>   
>   static const char * const dsi_qcm2290_bus_clk_names[] = {
> @@ -266,9 +254,8 @@ static const struct msm_dsi_config qcm2290_dsi_cfg = {
>   	.bus_clk_names = dsi_qcm2290_bus_clk_names,
>   	.num_bus_clks = ARRAY_SIZE(dsi_qcm2290_bus_clk_names),
>   	.io_start = {
> -		{ 0x5e94000 },
> +		{ 0x5e94000, 0 },
>   	},
> -	.num_dsi = 1,
>   };
>   
>   static const struct msm_dsi_host_cfg_ops msm_dsi_v2_host_ops = {
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_cfg.h b/drivers/gpu/drm/msm/dsi/dsi_cfg.h
> index df9f09876ccb..03493cc6b772 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_cfg.h
> +++ b/drivers/gpu/drm/msm/dsi/dsi_cfg.h
> @@ -41,8 +41,8 @@ struct msm_dsi_config {
>   	int num_regulators;
>   	const char * const *bus_clk_names;
>   	const int num_bus_clks;
> -	const resource_size_t io_start[VARIANTS_MAX][DSI_MAX];
> -	const int num_dsi;
> +	/* Allow + 1 entry for the zero-terminator */
> +	const resource_size_t io_start[VARIANTS_MAX][DSI_MAX + 1];
>   };
>   
>   struct msm_dsi_host_cfg_ops {
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> index 22ba8726b0ea..f5092b4d0757 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> @@ -1868,7 +1868,7 @@ static int dsi_host_get_id(struct msm_dsi_host *msm_host)
>   	if (!res)
>   		return -EINVAL;
>   
> -	for (i = 0; i < cfg->num_dsi; i++) {
> +	for (i = 0; cfg->io_start[0][i]; i++) {
>   		if (cfg->io_start[0][i] == res->start)
>   			return i;
>   	}

I think we have the easier way to do this: always loop towards DSI_MAX. 
Empty cells will contain the value of 0 which can not match against 
valid starting address.

Also please shift this patch to the first place, it will be logical to 
add VARIANT_MAX after removing num_dsi.
  
Konrad Dybcio Feb. 13, 2023, 9:18 a.m. UTC | #2
On 11.02.2023 14:19, Dmitry Baryshkov wrote:
> On 11/02/2023 13:51, Konrad Dybcio wrote:
>> In preparation for supporting multiple sets of possible base registers,
>> Zero-terminate the array that contains them to remove the need of
>> specifying num_dsi for each set.
>>
>> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
>> ---
>>   drivers/gpu/drm/msm/dsi/dsi_cfg.c  | 39 ++++++++++--------------------
>>   drivers/gpu/drm/msm/dsi/dsi_cfg.h  |  4 +--
>>   drivers/gpu/drm/msm/dsi/dsi_host.c |  2 +-
>>   3 files changed, 16 insertions(+), 29 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/dsi/dsi_cfg.c b/drivers/gpu/drm/msm/dsi/dsi_cfg.c
>> index 068d45b3a8f0..5f62c563bd1c 100644
>> --- a/drivers/gpu/drm/msm/dsi/dsi_cfg.c
>> +++ b/drivers/gpu/drm/msm/dsi/dsi_cfg.c
>> @@ -22,9 +22,8 @@ static const struct msm_dsi_config apq8064_dsi_cfg = {
>>       .bus_clk_names = dsi_v2_bus_clk_names,
>>       .num_bus_clks = ARRAY_SIZE(dsi_v2_bus_clk_names),
>>       .io_start = {
>> -        { 0x4700000, 0x5800000 },
>> +        { 0x4700000, 0x5800000, 0 },
>>       },
>> -    .num_dsi = 2,
>>   };
>>     static const char * const dsi_6g_bus_clk_names[] = {
>> @@ -44,9 +43,8 @@ static const struct msm_dsi_config msm8974_apq8084_dsi_cfg = {
>>       .bus_clk_names = dsi_6g_bus_clk_names,
>>       .num_bus_clks = ARRAY_SIZE(dsi_6g_bus_clk_names),
>>       .io_start = {
>> -        { 0xfd922800, 0xfd922b00 },
>> +        { 0xfd922800, 0xfd922b00, 0 },
>>       },
>> -    .num_dsi = 2,
>>   };
>>     static const char * const dsi_8916_bus_clk_names[] = {
>> @@ -65,9 +63,8 @@ static const struct msm_dsi_config msm8916_dsi_cfg = {
>>       .bus_clk_names = dsi_8916_bus_clk_names,
>>       .num_bus_clks = ARRAY_SIZE(dsi_8916_bus_clk_names),
>>       .io_start = {
>> -        { 0x1a98000 },
>> +        { 0x1a98000, 0 },
>>       },
>> -    .num_dsi = 1,
>>   };
>>     static const char * const dsi_8976_bus_clk_names[] = {
>> @@ -86,9 +83,8 @@ static const struct msm_dsi_config msm8976_dsi_cfg = {
>>       .bus_clk_names = dsi_8976_bus_clk_names,
>>       .num_bus_clks = ARRAY_SIZE(dsi_8976_bus_clk_names),
>>       .io_start = {
>> -        { 0x1a94000, 0x1a96000 },
>> +        { 0x1a94000, 0x1a96000, 0 },
>>       },
>> -    .num_dsi = 2,
>>   };
>>     static const struct regulator_bulk_data msm8994_dsi_regulators[] = {
>> @@ -107,9 +103,8 @@ static const struct msm_dsi_config msm8994_dsi_cfg = {
>>       .bus_clk_names = dsi_6g_bus_clk_names,
>>       .num_bus_clks = ARRAY_SIZE(dsi_6g_bus_clk_names),
>>       .io_start = {
>> -        { 0xfd998000, 0xfd9a0000 },
>> +        { 0xfd998000, 0xfd9a0000, 0 },
>>       },
>> -    .num_dsi = 2,
>>   };
>>     static const char * const dsi_8996_bus_clk_names[] = {
>> @@ -129,9 +124,8 @@ static const struct msm_dsi_config msm8996_dsi_cfg = {
>>       .bus_clk_names = dsi_8996_bus_clk_names,
>>       .num_bus_clks = ARRAY_SIZE(dsi_8996_bus_clk_names),
>>       .io_start = {
>> -        { 0x994000, 0x996000 },
>> +        { 0x994000, 0x996000, 0 },
>>       },
>> -    .num_dsi = 2,
>>   };
>>     static const char * const dsi_msm8998_bus_clk_names[] = {
>> @@ -150,9 +144,8 @@ static const struct msm_dsi_config msm8998_dsi_cfg = {
>>       .bus_clk_names = dsi_msm8998_bus_clk_names,
>>       .num_bus_clks = ARRAY_SIZE(dsi_msm8998_bus_clk_names),
>>       .io_start = {
>> -        { 0xc994000, 0xc996000 },
>> +        { 0xc994000, 0xc996000, 0 },
>>       },
>> -    .num_dsi = 2,
>>   };
>>     static const char * const dsi_sdm660_bus_clk_names[] = {
>> @@ -170,9 +163,8 @@ static const struct msm_dsi_config sdm660_dsi_cfg = {
>>       .bus_clk_names = dsi_sdm660_bus_clk_names,
>>       .num_bus_clks = ARRAY_SIZE(dsi_sdm660_bus_clk_names),
>>       .io_start = {
>> -        { 0xc994000, 0xc996000 },
>> +        { 0xc994000, 0xc996000, 0 },
>>       },
>> -    .num_dsi = 2,
>>   };
>>     static const char * const dsi_sdm845_bus_clk_names[] = {
>> @@ -194,9 +186,8 @@ static const struct msm_dsi_config sdm845_dsi_cfg = {
>>       .bus_clk_names = dsi_sdm845_bus_clk_names,
>>       .num_bus_clks = ARRAY_SIZE(dsi_sdm845_bus_clk_names),
>>       .io_start = {
>> -        { 0xae94000, 0xae96000 },
>> +        { 0xae94000, 0xae96000, 0 },
>>       },
>> -    .num_dsi = 2,
>>   };
>>     static const struct regulator_bulk_data sm8550_dsi_regulators[] = {
>> @@ -210,9 +201,8 @@ static const struct msm_dsi_config sm8550_dsi_cfg = {
>>       .bus_clk_names = dsi_sdm845_bus_clk_names,
>>       .num_bus_clks = ARRAY_SIZE(dsi_sdm845_bus_clk_names),
>>       .io_start = {
>> -        { 0xae94000, 0xae96000 },
>> +        { 0xae94000, 0xae96000, 0 },
>>       },
>> -    .num_dsi = 2,
>>   };
>>     static const struct regulator_bulk_data sc7180_dsi_regulators[] = {
>> @@ -226,9 +216,8 @@ static const struct msm_dsi_config sc7180_dsi_cfg = {
>>       .bus_clk_names = dsi_sc7180_bus_clk_names,
>>       .num_bus_clks = ARRAY_SIZE(dsi_sc7180_bus_clk_names),
>>       .io_start = {
>> -        { 0xae94000 },
>> +        { 0xae94000, 0 },
>>       },
>> -    .num_dsi = 1,
>>   };
>>     static const char * const dsi_sc7280_bus_clk_names[] = {
>> @@ -246,9 +235,8 @@ static const struct msm_dsi_config sc7280_dsi_cfg = {
>>       .bus_clk_names = dsi_sc7280_bus_clk_names,
>>       .num_bus_clks = ARRAY_SIZE(dsi_sc7280_bus_clk_names),
>>       .io_start = {
>> -        { 0xae94000, 0xae96000 },
>> +        { 0xae94000, 0xae96000, 0 },
>>       },
>> -    .num_dsi = 2,
>>   };
>>     static const char * const dsi_qcm2290_bus_clk_names[] = {
>> @@ -266,9 +254,8 @@ static const struct msm_dsi_config qcm2290_dsi_cfg = {
>>       .bus_clk_names = dsi_qcm2290_bus_clk_names,
>>       .num_bus_clks = ARRAY_SIZE(dsi_qcm2290_bus_clk_names),
>>       .io_start = {
>> -        { 0x5e94000 },
>> +        { 0x5e94000, 0 },
>>       },
>> -    .num_dsi = 1,
>>   };
>>     static const struct msm_dsi_host_cfg_ops msm_dsi_v2_host_ops = {
>> diff --git a/drivers/gpu/drm/msm/dsi/dsi_cfg.h b/drivers/gpu/drm/msm/dsi/dsi_cfg.h
>> index df9f09876ccb..03493cc6b772 100644
>> --- a/drivers/gpu/drm/msm/dsi/dsi_cfg.h
>> +++ b/drivers/gpu/drm/msm/dsi/dsi_cfg.h
>> @@ -41,8 +41,8 @@ struct msm_dsi_config {
>>       int num_regulators;
>>       const char * const *bus_clk_names;
>>       const int num_bus_clks;
>> -    const resource_size_t io_start[VARIANTS_MAX][DSI_MAX];
>> -    const int num_dsi;
>> +    /* Allow + 1 entry for the zero-terminator */
>> +    const resource_size_t io_start[VARIANTS_MAX][DSI_MAX + 1];
>>   };
>>     struct msm_dsi_host_cfg_ops {
>> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
>> index 22ba8726b0ea..f5092b4d0757 100644
>> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
>> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
>> @@ -1868,7 +1868,7 @@ static int dsi_host_get_id(struct msm_dsi_host *msm_host)
>>       if (!res)
>>           return -EINVAL;
>>   -    for (i = 0; i < cfg->num_dsi; i++) {
>> +    for (i = 0; cfg->io_start[0][i]; i++) {
>>           if (cfg->io_start[0][i] == res->start)
>>               return i;
>>       }
> 
> I think we have the easier way to do this: always loop towards DSI_MAX. Empty cells will contain the value of 0 which can not match against valid starting address.
Yep, your approach will save us NUM_ENTRIES*sizeof(u64) memory!

> 
> Also please shift this patch to the first place, it will be logical to add VARIANT_MAX after removing num_dsi.
Ack.

Konrad
>
  
Dmitry Baryshkov Feb. 13, 2023, 11:41 a.m. UTC | #3
On 13/02/2023 11:18, Konrad Dybcio wrote:
> 
> 
> On 11.02.2023 14:19, Dmitry Baryshkov wrote:
>> On 11/02/2023 13:51, Konrad Dybcio wrote:
>>> In preparation for supporting multiple sets of possible base registers,
>>> Zero-terminate the array that contains them to remove the need of
>>> specifying num_dsi for each set.
>>>
>>> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
>>> ---
>>>    drivers/gpu/drm/msm/dsi/dsi_cfg.c  | 39 ++++++++++--------------------
>>>    drivers/gpu/drm/msm/dsi/dsi_cfg.h  |  4 +--
>>>    drivers/gpu/drm/msm/dsi/dsi_host.c |  2 +-
>>>    3 files changed, 16 insertions(+), 29 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/msm/dsi/dsi_cfg.c b/drivers/gpu/drm/msm/dsi/dsi_cfg.c
>>> index 068d45b3a8f0..5f62c563bd1c 100644
>>> --- a/drivers/gpu/drm/msm/dsi/dsi_cfg.c
>>> +++ b/drivers/gpu/drm/msm/dsi/dsi_cfg.c
>>> @@ -22,9 +22,8 @@ static const struct msm_dsi_config apq8064_dsi_cfg = {
>>>        .bus_clk_names = dsi_v2_bus_clk_names,
>>>        .num_bus_clks = ARRAY_SIZE(dsi_v2_bus_clk_names),
>>>        .io_start = {
>>> -        { 0x4700000, 0x5800000 },
>>> +        { 0x4700000, 0x5800000, 0 },
>>>        },
>>> -    .num_dsi = 2,
>>>    };
>>>      static const char * const dsi_6g_bus_clk_names[] = {
>>> @@ -44,9 +43,8 @@ static const struct msm_dsi_config msm8974_apq8084_dsi_cfg = {
>>>        .bus_clk_names = dsi_6g_bus_clk_names,
>>>        .num_bus_clks = ARRAY_SIZE(dsi_6g_bus_clk_names),
>>>        .io_start = {
>>> -        { 0xfd922800, 0xfd922b00 },
>>> +        { 0xfd922800, 0xfd922b00, 0 },
>>>        },
>>> -    .num_dsi = 2,
>>>    };
>>>      static const char * const dsi_8916_bus_clk_names[] = {
>>> @@ -65,9 +63,8 @@ static const struct msm_dsi_config msm8916_dsi_cfg = {
>>>        .bus_clk_names = dsi_8916_bus_clk_names,
>>>        .num_bus_clks = ARRAY_SIZE(dsi_8916_bus_clk_names),
>>>        .io_start = {
>>> -        { 0x1a98000 },
>>> +        { 0x1a98000, 0 },
>>>        },
>>> -    .num_dsi = 1,
>>>    };
>>>      static const char * const dsi_8976_bus_clk_names[] = {
>>> @@ -86,9 +83,8 @@ static const struct msm_dsi_config msm8976_dsi_cfg = {
>>>        .bus_clk_names = dsi_8976_bus_clk_names,
>>>        .num_bus_clks = ARRAY_SIZE(dsi_8976_bus_clk_names),
>>>        .io_start = {
>>> -        { 0x1a94000, 0x1a96000 },
>>> +        { 0x1a94000, 0x1a96000, 0 },
>>>        },
>>> -    .num_dsi = 2,
>>>    };
>>>      static const struct regulator_bulk_data msm8994_dsi_regulators[] = {
>>> @@ -107,9 +103,8 @@ static const struct msm_dsi_config msm8994_dsi_cfg = {
>>>        .bus_clk_names = dsi_6g_bus_clk_names,
>>>        .num_bus_clks = ARRAY_SIZE(dsi_6g_bus_clk_names),
>>>        .io_start = {
>>> -        { 0xfd998000, 0xfd9a0000 },
>>> +        { 0xfd998000, 0xfd9a0000, 0 },
>>>        },
>>> -    .num_dsi = 2,
>>>    };
>>>      static const char * const dsi_8996_bus_clk_names[] = {
>>> @@ -129,9 +124,8 @@ static const struct msm_dsi_config msm8996_dsi_cfg = {
>>>        .bus_clk_names = dsi_8996_bus_clk_names,
>>>        .num_bus_clks = ARRAY_SIZE(dsi_8996_bus_clk_names),
>>>        .io_start = {
>>> -        { 0x994000, 0x996000 },
>>> +        { 0x994000, 0x996000, 0 },
>>>        },
>>> -    .num_dsi = 2,
>>>    };
>>>      static const char * const dsi_msm8998_bus_clk_names[] = {
>>> @@ -150,9 +144,8 @@ static const struct msm_dsi_config msm8998_dsi_cfg = {
>>>        .bus_clk_names = dsi_msm8998_bus_clk_names,
>>>        .num_bus_clks = ARRAY_SIZE(dsi_msm8998_bus_clk_names),
>>>        .io_start = {
>>> -        { 0xc994000, 0xc996000 },
>>> +        { 0xc994000, 0xc996000, 0 },
>>>        },
>>> -    .num_dsi = 2,
>>>    };
>>>      static const char * const dsi_sdm660_bus_clk_names[] = {
>>> @@ -170,9 +163,8 @@ static const struct msm_dsi_config sdm660_dsi_cfg = {
>>>        .bus_clk_names = dsi_sdm660_bus_clk_names,
>>>        .num_bus_clks = ARRAY_SIZE(dsi_sdm660_bus_clk_names),
>>>        .io_start = {
>>> -        { 0xc994000, 0xc996000 },
>>> +        { 0xc994000, 0xc996000, 0 },
>>>        },
>>> -    .num_dsi = 2,
>>>    };
>>>      static const char * const dsi_sdm845_bus_clk_names[] = {
>>> @@ -194,9 +186,8 @@ static const struct msm_dsi_config sdm845_dsi_cfg = {
>>>        .bus_clk_names = dsi_sdm845_bus_clk_names,
>>>        .num_bus_clks = ARRAY_SIZE(dsi_sdm845_bus_clk_names),
>>>        .io_start = {
>>> -        { 0xae94000, 0xae96000 },
>>> +        { 0xae94000, 0xae96000, 0 },
>>>        },
>>> -    .num_dsi = 2,
>>>    };
>>>      static const struct regulator_bulk_data sm8550_dsi_regulators[] = {
>>> @@ -210,9 +201,8 @@ static const struct msm_dsi_config sm8550_dsi_cfg = {
>>>        .bus_clk_names = dsi_sdm845_bus_clk_names,
>>>        .num_bus_clks = ARRAY_SIZE(dsi_sdm845_bus_clk_names),
>>>        .io_start = {
>>> -        { 0xae94000, 0xae96000 },
>>> +        { 0xae94000, 0xae96000, 0 },
>>>        },
>>> -    .num_dsi = 2,
>>>    };
>>>      static const struct regulator_bulk_data sc7180_dsi_regulators[] = {
>>> @@ -226,9 +216,8 @@ static const struct msm_dsi_config sc7180_dsi_cfg = {
>>>        .bus_clk_names = dsi_sc7180_bus_clk_names,
>>>        .num_bus_clks = ARRAY_SIZE(dsi_sc7180_bus_clk_names),
>>>        .io_start = {
>>> -        { 0xae94000 },
>>> +        { 0xae94000, 0 },
>>>        },
>>> -    .num_dsi = 1,
>>>    };
>>>      static const char * const dsi_sc7280_bus_clk_names[] = {
>>> @@ -246,9 +235,8 @@ static const struct msm_dsi_config sc7280_dsi_cfg = {
>>>        .bus_clk_names = dsi_sc7280_bus_clk_names,
>>>        .num_bus_clks = ARRAY_SIZE(dsi_sc7280_bus_clk_names),
>>>        .io_start = {
>>> -        { 0xae94000, 0xae96000 },
>>> +        { 0xae94000, 0xae96000, 0 },
>>>        },
>>> -    .num_dsi = 2,
>>>    };
>>>      static const char * const dsi_qcm2290_bus_clk_names[] = {
>>> @@ -266,9 +254,8 @@ static const struct msm_dsi_config qcm2290_dsi_cfg = {
>>>        .bus_clk_names = dsi_qcm2290_bus_clk_names,
>>>        .num_bus_clks = ARRAY_SIZE(dsi_qcm2290_bus_clk_names),
>>>        .io_start = {
>>> -        { 0x5e94000 },
>>> +        { 0x5e94000, 0 },
>>>        },
>>> -    .num_dsi = 1,
>>>    };
>>>      static const struct msm_dsi_host_cfg_ops msm_dsi_v2_host_ops = {
>>> diff --git a/drivers/gpu/drm/msm/dsi/dsi_cfg.h b/drivers/gpu/drm/msm/dsi/dsi_cfg.h
>>> index df9f09876ccb..03493cc6b772 100644
>>> --- a/drivers/gpu/drm/msm/dsi/dsi_cfg.h
>>> +++ b/drivers/gpu/drm/msm/dsi/dsi_cfg.h
>>> @@ -41,8 +41,8 @@ struct msm_dsi_config {
>>>        int num_regulators;
>>>        const char * const *bus_clk_names;
>>>        const int num_bus_clks;
>>> -    const resource_size_t io_start[VARIANTS_MAX][DSI_MAX];
>>> -    const int num_dsi;
>>> +    /* Allow + 1 entry for the zero-terminator */
>>> +    const resource_size_t io_start[VARIANTS_MAX][DSI_MAX + 1];
>>>    };
>>>      struct msm_dsi_host_cfg_ops {
>>> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
>>> index 22ba8726b0ea..f5092b4d0757 100644
>>> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
>>> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
>>> @@ -1868,7 +1868,7 @@ static int dsi_host_get_id(struct msm_dsi_host *msm_host)
>>>        if (!res)
>>>            return -EINVAL;
>>>    -    for (i = 0; i < cfg->num_dsi; i++) {
>>> +    for (i = 0; cfg->io_start[0][i]; i++) {
>>>            if (cfg->io_start[0][i] == res->start)
>>>                return i;
>>>        }
>>
>> I think we have the easier way to do this: always loop towards DSI_MAX. Empty cells will contain the value of 0 which can not match against valid starting address.
> Yep, your approach will save us NUM_ENTRIES*sizeof(u64) memory!

As for me it not about saving memory, but rather about the driver logic. 
Compare:
- We have two possible DSI hosts, one which is ocassionally absent thus 
the address is 0

vs

- We have a zero-terminated list of 2+1 entries for not more than two 
DSI hosts.

> 
>>
>> Also please shift this patch to the first place, it will be logical to add VARIANT_MAX after removing num_dsi.
> Ack.
> 
> Konrad
>>
  

Patch

diff --git a/drivers/gpu/drm/msm/dsi/dsi_cfg.c b/drivers/gpu/drm/msm/dsi/dsi_cfg.c
index 068d45b3a8f0..5f62c563bd1c 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_cfg.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_cfg.c
@@ -22,9 +22,8 @@  static const struct msm_dsi_config apq8064_dsi_cfg = {
 	.bus_clk_names = dsi_v2_bus_clk_names,
 	.num_bus_clks = ARRAY_SIZE(dsi_v2_bus_clk_names),
 	.io_start = {
-		{ 0x4700000, 0x5800000 },
+		{ 0x4700000, 0x5800000, 0 },
 	},
-	.num_dsi = 2,
 };
 
 static const char * const dsi_6g_bus_clk_names[] = {
@@ -44,9 +43,8 @@  static const struct msm_dsi_config msm8974_apq8084_dsi_cfg = {
 	.bus_clk_names = dsi_6g_bus_clk_names,
 	.num_bus_clks = ARRAY_SIZE(dsi_6g_bus_clk_names),
 	.io_start = {
-		{ 0xfd922800, 0xfd922b00 },
+		{ 0xfd922800, 0xfd922b00, 0 },
 	},
-	.num_dsi = 2,
 };
 
 static const char * const dsi_8916_bus_clk_names[] = {
@@ -65,9 +63,8 @@  static const struct msm_dsi_config msm8916_dsi_cfg = {
 	.bus_clk_names = dsi_8916_bus_clk_names,
 	.num_bus_clks = ARRAY_SIZE(dsi_8916_bus_clk_names),
 	.io_start = {
-		{ 0x1a98000 },
+		{ 0x1a98000, 0 },
 	},
-	.num_dsi = 1,
 };
 
 static const char * const dsi_8976_bus_clk_names[] = {
@@ -86,9 +83,8 @@  static const struct msm_dsi_config msm8976_dsi_cfg = {
 	.bus_clk_names = dsi_8976_bus_clk_names,
 	.num_bus_clks = ARRAY_SIZE(dsi_8976_bus_clk_names),
 	.io_start = {
-		{ 0x1a94000, 0x1a96000 },
+		{ 0x1a94000, 0x1a96000, 0 },
 	},
-	.num_dsi = 2,
 };
 
 static const struct regulator_bulk_data msm8994_dsi_regulators[] = {
@@ -107,9 +103,8 @@  static const struct msm_dsi_config msm8994_dsi_cfg = {
 	.bus_clk_names = dsi_6g_bus_clk_names,
 	.num_bus_clks = ARRAY_SIZE(dsi_6g_bus_clk_names),
 	.io_start = {
-		{ 0xfd998000, 0xfd9a0000 },
+		{ 0xfd998000, 0xfd9a0000, 0 },
 	},
-	.num_dsi = 2,
 };
 
 static const char * const dsi_8996_bus_clk_names[] = {
@@ -129,9 +124,8 @@  static const struct msm_dsi_config msm8996_dsi_cfg = {
 	.bus_clk_names = dsi_8996_bus_clk_names,
 	.num_bus_clks = ARRAY_SIZE(dsi_8996_bus_clk_names),
 	.io_start = {
-		{ 0x994000, 0x996000 },
+		{ 0x994000, 0x996000, 0 },
 	},
-	.num_dsi = 2,
 };
 
 static const char * const dsi_msm8998_bus_clk_names[] = {
@@ -150,9 +144,8 @@  static const struct msm_dsi_config msm8998_dsi_cfg = {
 	.bus_clk_names = dsi_msm8998_bus_clk_names,
 	.num_bus_clks = ARRAY_SIZE(dsi_msm8998_bus_clk_names),
 	.io_start = {
-		{ 0xc994000, 0xc996000 },
+		{ 0xc994000, 0xc996000, 0 },
 	},
-	.num_dsi = 2,
 };
 
 static const char * const dsi_sdm660_bus_clk_names[] = {
@@ -170,9 +163,8 @@  static const struct msm_dsi_config sdm660_dsi_cfg = {
 	.bus_clk_names = dsi_sdm660_bus_clk_names,
 	.num_bus_clks = ARRAY_SIZE(dsi_sdm660_bus_clk_names),
 	.io_start = {
-		{ 0xc994000, 0xc996000 },
+		{ 0xc994000, 0xc996000, 0 },
 	},
-	.num_dsi = 2,
 };
 
 static const char * const dsi_sdm845_bus_clk_names[] = {
@@ -194,9 +186,8 @@  static const struct msm_dsi_config sdm845_dsi_cfg = {
 	.bus_clk_names = dsi_sdm845_bus_clk_names,
 	.num_bus_clks = ARRAY_SIZE(dsi_sdm845_bus_clk_names),
 	.io_start = {
-		{ 0xae94000, 0xae96000 },
+		{ 0xae94000, 0xae96000, 0 },
 	},
-	.num_dsi = 2,
 };
 
 static const struct regulator_bulk_data sm8550_dsi_regulators[] = {
@@ -210,9 +201,8 @@  static const struct msm_dsi_config sm8550_dsi_cfg = {
 	.bus_clk_names = dsi_sdm845_bus_clk_names,
 	.num_bus_clks = ARRAY_SIZE(dsi_sdm845_bus_clk_names),
 	.io_start = {
-		{ 0xae94000, 0xae96000 },
+		{ 0xae94000, 0xae96000, 0 },
 	},
-	.num_dsi = 2,
 };
 
 static const struct regulator_bulk_data sc7180_dsi_regulators[] = {
@@ -226,9 +216,8 @@  static const struct msm_dsi_config sc7180_dsi_cfg = {
 	.bus_clk_names = dsi_sc7180_bus_clk_names,
 	.num_bus_clks = ARRAY_SIZE(dsi_sc7180_bus_clk_names),
 	.io_start = {
-		{ 0xae94000 },
+		{ 0xae94000, 0 },
 	},
-	.num_dsi = 1,
 };
 
 static const char * const dsi_sc7280_bus_clk_names[] = {
@@ -246,9 +235,8 @@  static const struct msm_dsi_config sc7280_dsi_cfg = {
 	.bus_clk_names = dsi_sc7280_bus_clk_names,
 	.num_bus_clks = ARRAY_SIZE(dsi_sc7280_bus_clk_names),
 	.io_start = {
-		{ 0xae94000, 0xae96000 },
+		{ 0xae94000, 0xae96000, 0 },
 	},
-	.num_dsi = 2,
 };
 
 static const char * const dsi_qcm2290_bus_clk_names[] = {
@@ -266,9 +254,8 @@  static const struct msm_dsi_config qcm2290_dsi_cfg = {
 	.bus_clk_names = dsi_qcm2290_bus_clk_names,
 	.num_bus_clks = ARRAY_SIZE(dsi_qcm2290_bus_clk_names),
 	.io_start = {
-		{ 0x5e94000 },
+		{ 0x5e94000, 0 },
 	},
-	.num_dsi = 1,
 };
 
 static const struct msm_dsi_host_cfg_ops msm_dsi_v2_host_ops = {
diff --git a/drivers/gpu/drm/msm/dsi/dsi_cfg.h b/drivers/gpu/drm/msm/dsi/dsi_cfg.h
index df9f09876ccb..03493cc6b772 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_cfg.h
+++ b/drivers/gpu/drm/msm/dsi/dsi_cfg.h
@@ -41,8 +41,8 @@  struct msm_dsi_config {
 	int num_regulators;
 	const char * const *bus_clk_names;
 	const int num_bus_clks;
-	const resource_size_t io_start[VARIANTS_MAX][DSI_MAX];
-	const int num_dsi;
+	/* Allow + 1 entry for the zero-terminator */
+	const resource_size_t io_start[VARIANTS_MAX][DSI_MAX + 1];
 };
 
 struct msm_dsi_host_cfg_ops {
diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
index 22ba8726b0ea..f5092b4d0757 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -1868,7 +1868,7 @@  static int dsi_host_get_id(struct msm_dsi_host *msm_host)
 	if (!res)
 		return -EINVAL;
 
-	for (i = 0; i < cfg->num_dsi; i++) {
+	for (i = 0; cfg->io_start[0][i]; i++) {
 		if (cfg->io_start[0][i] == res->start)
 			return i;
 	}