Re: [PATCH 2/2] i2c: xgene-slimpro: Add ACPI support by using PCC mailbox

[Wolfram Sang]

> > I think it doesn't make sense to print a dev_err and return ENODEV which
> > is treated by the driver core as a non-error. It means "not present, but
> > OK". You probably want other error codes here.
> 
> How about -EINVAL for these -ENODEV error codes? Do you have any suggestion?

-EINVAL will do, I would go for -ENOENT, probably. But it doesn't matter
much.



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Re: [PATCH 2/2] i2c: xgene-slimpro: Add ACPI support by using PCC mailbox

[Wolfram Sang]

> > I think it doesn't make sense to print a dev_err and return ENODEV which
> > is treated by the driver core as a non-error. It means "not present, but
> > OK". You probably want other error codes here.
> 
> How about -EINVAL for these -ENODEV error codes? Do you have any suggestion?

-EINVAL will do, I would go for -ENOENT, probably. But it doesn't matter
much.



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Re: [PATCH 2/2] i2c: xgene-slimpro: Add ACPI support by using PCC mailbox

[Hoan Tran]

Hi Wolfram,

On Thu, Apr 20, 2017 at 1:05 AM, Wolfram Sang  wrote:
> Hi,
>
> have you tested these patches also without PCC? So, we can be sure there
> is no regression?

These patches are tested with/without PCC.

>
>> diff --git a/drivers/i2c/busses/i2c-xgene-slimpro.c 
>> b/drivers/i2c/busses/i2c-xgene-slimpro.c
>> index 96545aa..a5771c1 100644
>> --- a/drivers/i2c/busses/i2c-xgene-slimpro.c
>> +++ b/drivers/i2c/busses/i2c-xgene-slimpro.c
>> @@ -32,6 +32,8 @@
>>  #include 
>>  #include 
>>
>> +#include 
>> +
>
> Please keep it sorted alphabetically.
>
>> +#define PCC_CMD_GENERATE_DB_INT  BIT(15)
>> +#define PCC_STS_CMD_COMPLETE BIT(0)
>> +#define PCC_STS_SCI_DOORBELL BIT(1)
>> +#define PCC_STS_ERR  BIT(2)
>> +#define PCC_STS_PLAT_NOTIFY  BIT(3)
>
> Please keep it sorted by number.
>
>> + if (!acpi_disabled) {
>> + mutex_lock(>tx_mutex);
>> + init_completion(>rd_complete);
>
> reinit_completion?

OK,

>
>> + slimpro_i2c_pcc_tx_prepare(ctx, msg);
>> + }
>> +
>> + mutex_init(>tx_mutex);
>
> Why this mutex, by the way? The i2c-core serializes access to the
> adapter. Maybe I am missing something?

That's a good point, let me remove this mutex.

>
>> + cppc_ss = ctx->mbox_chan->con_priv;
>> + if (!cppc_ss) {
>> + dev_err(>dev, "PPC subspace not found\n");
>> + rc = -ENODEV;
>> + goto mbox_err;
>> + }
>> +
>> + if (!ctx->mbox_chan->mbox->txdone_irq) {
>> + dev_err(>dev, "PCC IRQ not supported\n");
>> + rc = -ENODEV;
>> + goto mbox_err;
>> + }
>>
>> + /*
>> +  * This is the shared communication region
>> +  * for the OS and Platform to communicate over.
>> +  */
>> + ctx->comm_base_addr = cppc_ss->base_address;
>> + if (ctx->comm_base_addr) {
>> + ctx->pcc_comm_addr = memremap(ctx->comm_base_addr,
>> +   cppc_ss->length,
>> +   MEMREMAP_WB);
>> + } else {
>> + dev_err(>dev, "Failed to get PCC comm region\n");
>> + rc = -ENODEV;
>> + goto mbox_err;
>> + }
>
> I think it doesn't make sense to print a dev_err and return ENODEV which
> is treated by the driver core as a non-error. It means "not present, but
> OK". You probably want other error codes here.

How about -EINVAL for these -ENODEV error codes? Do you have any suggestion?

Thank for your comments!
Hoan


>
> Regards,
>
>Wolfram
>

Re: [PATCH 2/2] i2c: xgene-slimpro: Add ACPI support by using PCC mailbox

[Hoan Tran]

Hi Wolfram,

On Thu, Apr 20, 2017 at 1:05 AM, Wolfram Sang  wrote:
> Hi,
>
> have you tested these patches also without PCC? So, we can be sure there
> is no regression?

These patches are tested with/without PCC.

>
>> diff --git a/drivers/i2c/busses/i2c-xgene-slimpro.c 
>> b/drivers/i2c/busses/i2c-xgene-slimpro.c
>> index 96545aa..a5771c1 100644
>> --- a/drivers/i2c/busses/i2c-xgene-slimpro.c
>> +++ b/drivers/i2c/busses/i2c-xgene-slimpro.c
>> @@ -32,6 +32,8 @@
>>  #include 
>>  #include 
>>
>> +#include 
>> +
>
> Please keep it sorted alphabetically.
>
>> +#define PCC_CMD_GENERATE_DB_INT  BIT(15)
>> +#define PCC_STS_CMD_COMPLETE BIT(0)
>> +#define PCC_STS_SCI_DOORBELL BIT(1)
>> +#define PCC_STS_ERR  BIT(2)
>> +#define PCC_STS_PLAT_NOTIFY  BIT(3)
>
> Please keep it sorted by number.
>
>> + if (!acpi_disabled) {
>> + mutex_lock(>tx_mutex);
>> + init_completion(>rd_complete);
>
> reinit_completion?

OK,

>
>> + slimpro_i2c_pcc_tx_prepare(ctx, msg);
>> + }
>> +
>> + mutex_init(>tx_mutex);
>
> Why this mutex, by the way? The i2c-core serializes access to the
> adapter. Maybe I am missing something?

That's a good point, let me remove this mutex.

>
>> + cppc_ss = ctx->mbox_chan->con_priv;
>> + if (!cppc_ss) {
>> + dev_err(>dev, "PPC subspace not found\n");
>> + rc = -ENODEV;
>> + goto mbox_err;
>> + }
>> +
>> + if (!ctx->mbox_chan->mbox->txdone_irq) {
>> + dev_err(>dev, "PCC IRQ not supported\n");
>> + rc = -ENODEV;
>> + goto mbox_err;
>> + }
>>
>> + /*
>> +  * This is the shared communication region
>> +  * for the OS and Platform to communicate over.
>> +  */
>> + ctx->comm_base_addr = cppc_ss->base_address;
>> + if (ctx->comm_base_addr) {
>> + ctx->pcc_comm_addr = memremap(ctx->comm_base_addr,
>> +   cppc_ss->length,
>> +   MEMREMAP_WB);
>> + } else {
>> + dev_err(>dev, "Failed to get PCC comm region\n");
>> + rc = -ENODEV;
>> + goto mbox_err;
>> + }
>
> I think it doesn't make sense to print a dev_err and return ENODEV which
> is treated by the driver core as a non-error. It means "not present, but
> OK". You probably want other error codes here.

How about -EINVAL for these -ENODEV error codes? Do you have any suggestion?

Thank for your comments!
Hoan


>
> Regards,
>
>Wolfram
>

Re: [PATCH 2/2] i2c: xgene-slimpro: Add ACPI support by using PCC mailbox

[Wolfram Sang]

Hi,

have you tested these patches also without PCC? So, we can be sure there
is no regression?

> diff --git a/drivers/i2c/busses/i2c-xgene-slimpro.c 
> b/drivers/i2c/busses/i2c-xgene-slimpro.c
> index 96545aa..a5771c1 100644
> --- a/drivers/i2c/busses/i2c-xgene-slimpro.c
> +++ b/drivers/i2c/busses/i2c-xgene-slimpro.c
> @@ -32,6 +32,8 @@
>  #include 
>  #include 
>  
> +#include 
> +

Please keep it sorted alphabetically.

> +#define PCC_CMD_GENERATE_DB_INT  BIT(15)
> +#define PCC_STS_CMD_COMPLETE BIT(0)
> +#define PCC_STS_SCI_DOORBELL BIT(1)
> +#define PCC_STS_ERR  BIT(2)
> +#define PCC_STS_PLAT_NOTIFY  BIT(3)

Please keep it sorted by number.

> + if (!acpi_disabled) {
> + mutex_lock(>tx_mutex);
> + init_completion(>rd_complete);

reinit_completion?

> + slimpro_i2c_pcc_tx_prepare(ctx, msg);
> + }
> +
> + mutex_init(>tx_mutex);

Why this mutex, by the way? The i2c-core serializes access to the
adapter. Maybe I am missing something?

> + cppc_ss = ctx->mbox_chan->con_priv;
> + if (!cppc_ss) {
> + dev_err(>dev, "PPC subspace not found\n");
> + rc = -ENODEV;
> + goto mbox_err;
> + }
> +
> + if (!ctx->mbox_chan->mbox->txdone_irq) {
> + dev_err(>dev, "PCC IRQ not supported\n");
> + rc = -ENODEV;
> + goto mbox_err;
> + }
>  
> + /*
> +  * This is the shared communication region
> +  * for the OS and Platform to communicate over.
> +  */
> + ctx->comm_base_addr = cppc_ss->base_address;
> + if (ctx->comm_base_addr) {
> + ctx->pcc_comm_addr = memremap(ctx->comm_base_addr,
> +   cppc_ss->length,
> +   MEMREMAP_WB);
> + } else {
> + dev_err(>dev, "Failed to get PCC comm region\n");
> + rc = -ENODEV;
> + goto mbox_err;
> + }

I think it doesn't make sense to print a dev_err and return ENODEV which
is treated by the driver core as a non-error. It means "not present, but
OK". You probably want other error codes here.

Regards,

   Wolfram



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Re: [PATCH 2/2] i2c: xgene-slimpro: Add ACPI support by using PCC mailbox

[Wolfram Sang]

Hi,

have you tested these patches also without PCC? So, we can be sure there
is no regression?

> diff --git a/drivers/i2c/busses/i2c-xgene-slimpro.c 
> b/drivers/i2c/busses/i2c-xgene-slimpro.c
> index 96545aa..a5771c1 100644
> --- a/drivers/i2c/busses/i2c-xgene-slimpro.c
> +++ b/drivers/i2c/busses/i2c-xgene-slimpro.c
> @@ -32,6 +32,8 @@
>  #include 
>  #include 
>  
> +#include 
> +

Please keep it sorted alphabetically.

> +#define PCC_CMD_GENERATE_DB_INT  BIT(15)
> +#define PCC_STS_CMD_COMPLETE BIT(0)
> +#define PCC_STS_SCI_DOORBELL BIT(1)
> +#define PCC_STS_ERR  BIT(2)
> +#define PCC_STS_PLAT_NOTIFY  BIT(3)

Please keep it sorted by number.

> + if (!acpi_disabled) {
> + mutex_lock(>tx_mutex);
> + init_completion(>rd_complete);

reinit_completion?

> + slimpro_i2c_pcc_tx_prepare(ctx, msg);
> + }
> +
> + mutex_init(>tx_mutex);

Why this mutex, by the way? The i2c-core serializes access to the
adapter. Maybe I am missing something?

> + cppc_ss = ctx->mbox_chan->con_priv;
> + if (!cppc_ss) {
> + dev_err(>dev, "PPC subspace not found\n");
> + rc = -ENODEV;
> + goto mbox_err;
> + }
> +
> + if (!ctx->mbox_chan->mbox->txdone_irq) {
> + dev_err(>dev, "PCC IRQ not supported\n");
> + rc = -ENODEV;
> + goto mbox_err;
> + }
>  
> + /*
> +  * This is the shared communication region
> +  * for the OS and Platform to communicate over.
> +  */
> + ctx->comm_base_addr = cppc_ss->base_address;
> + if (ctx->comm_base_addr) {
> + ctx->pcc_comm_addr = memremap(ctx->comm_base_addr,
> +   cppc_ss->length,
> +   MEMREMAP_WB);
> + } else {
> + dev_err(>dev, "Failed to get PCC comm region\n");
> + rc = -ENODEV;
> + goto mbox_err;
> + }

I think it doesn't make sense to print a dev_err and return ENODEV which
is treated by the driver core as a non-error. It means "not present, but
OK". You probably want other error codes here.

Regards,

   Wolfram



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