Re: [PATCH v2 10/42] misc/mei/hdcp: Initiate Wired HDCP2.2 Tx Session

[Ramalingam C <ramalingam.c@intel.com>]

On Monday 12 March 2018 05:02 PM, Winkler, Tomas wrote:
>>
>>
>> On Thursday 08 March 2018 06:47 PM, Winkler, Tomas wrote:
>>>> Request ME FW to start the HDCP2.2 session for a intel port.
>>>> Prepares payloads for command WIRED_INITIATE_HDCP2_SESSION and
>> sent
>>>> to ME FW.
>>>>
>>>> On Success, ME FW will start a HDCP2.2 session for the port and
>>>> provides the content for HDCP2.2 AKE_Init message.
>>>>
>>>> v2:
>>>>     Rebased.
>>>>
>>>> Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
>>>> ---
>>>>    drivers/misc/mei/hdcp/mei_hdcp.c | 73
>>>> ++++++++++++++++++++++++++++++++++++++++
>>>>    include/linux/mei_hdcp.h         | 11 ++++++
>>>>    2 files changed, 84 insertions(+)
>>>>
>>>> diff --git a/drivers/misc/mei/hdcp/mei_hdcp.c
>>>> b/drivers/misc/mei/hdcp/mei_hdcp.c
>>>> index 63f77800a6f7..516ad6a40616 100644
>>>> --- a/drivers/misc/mei/hdcp/mei_hdcp.c
>>>> +++ b/drivers/misc/mei/hdcp/mei_hdcp.c
>>>> @@ -29,6 +29,7 @@
>>>>    #include <linux/module.h>
>>>>    #include <linux/slab.h>
>>>>    #include <linux/uuid.h>
>>>> +#include <drm/drm_connector.h>
>>>>
>>>>    #include "mei_hdcp.h"
>>>>
>>>> @@ -46,6 +47,78 @@ static inline bool
>>>> mei_cldev_active_and_enabled(struct mei_cl_device *cldev)
>>>>    	return mei_cldev_enabled(cldev);
>>>>    }
>>>>
>>>> +/**
>>>> + * mei_initiate_hdcp2_session:
>>>> + *	Function to start a Wired HDCP2.2 Tx Session with ME FW
>>>> + *
>>>> + * @data		: Intel HW specific Data
>>>> + * @ake_data		: ptr to store AKE_Init
>>>> + *
>>>> + * Returns 0 on Success, <0 on Failure.
>>>> + */
>>>> +int mei_initiate_hdcp2_session(struct mei_hdcp_data *data,
>>>> +			       struct hdcp2_ake_init *ake_data) {
>>> You should use cldev as a first argument for all those functions
>> data has it as a member. Should it be explicit?
>
> I believe, you should.
> cldev is the object this function operates on so it should be explicitly and data provides the input paramterss
Sure. I will follow that.
>
> Thanks
> Tomas
>
>>>> +	/* check for the mei_device enabled or not */
>>>> +	if (!mei_cldev_active_and_enabled(data->cldev))
>>>> +		return -ENODEV;
>>> No reason cldev will be NULL here.
>> Ok. But device could be disabled right? we might want to check the enabled
>> state of the device?
> The device might go under reset any time during operations.
> so it is useless to test at this point (unless you know some other flow to take)
> as the underlying service already checks that for you and will return  appropriate error (ENODEV).
> Thanks
> Tomas

Thanks for the explanation. I will drop the check here.

--Ram
>
>>>> +	dev = &data->cldev->dev;
>>>> +
>>>> +	/* Fill header details */
>>> Those types of comments are redundant.
>>>> +	session_init_in.header.api_version = HDCP_API_VERSION;
>>>> +	session_init_in.header.command_id =
>>>> WIRED_INITIATE_HDCP2_SESSION;
>>>> +	session_init_in.header.status = ME_HDCP_STATUS_SUCCESS;
>>>> +	session_init_in.header.buffer_len =
>>>> +
>>>> 	WIRED_CMD_BUF_LEN_INITIATE_HDCP2_SESSION_IN;
>>>> +
>>>> +	/* Fill in the In Data */
>>> Those types of comments are redundant.
>>>> +	session_init_in.port.integrated_port_type = data->port_type;
>>>> +	session_init_in.port.physical_port = data->port;
>>>> +	session_init_in.protocol = (uint8_t)data->protocol;
>>>> +
>>>> +	/* Request to ME */
>>>> +	byte = mei_cldev_send(data->cldev, (u8 *)&session_init_in,
>>>> +			      sizeof(session_init_in));
>>>> +	if (byte < 0) {
>>>> +		dev_err(dev, "mei_cldev_send failed. %d\n", (int)byte);
>>>> +		return byte;
>>>> +	}
>>>> +
>>>> +	/* Response from ME */
>>>> +	byte = mei_cldev_recv(data->cldev, (u8 *)&session_init_out,
>>>> +			      sizeof(session_init_out));
>>>> +	if (byte < 0) {
>>>> +		dev_err(dev, "mei_cldev_recv failed. %d\n", (int)byte);
>>>> +		return byte;
>>>> +	}
>>>> +
>>>> +	status = (enum me_hdcp_status)session_init_out.header.status;
>>> Useless cast
>> Oops. Will remove it.
>>
>> --Ram
>>>> +	if (status != ME_HDCP_STATUS_SUCCESS) {
>>>> +		dev_err(dev, "ME cmd 0x%08X Failed. Status: 0x%X\n",
>>>> +			WIRED_INITIATE_HDCP2_SESSION, status);
>>>> +		return -1;
>>>> +	}
>>>> +
>>>> +	ake_data->msg_id = HDCP_2_2_AKE_INIT;
>>>> +	ake_data->tx_caps = session_init_out.tx_caps;
>>>> +	memcpy(ake_data->r_tx, session_init_out.r_tx,
>>>> +	       sizeof(session_init_out.r_tx));
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +EXPORT_SYMBOL(mei_initiate_hdcp2_session);
>>>> +
>>>>    static int mei_hdcp_probe(struct mei_cl_device *cldev,
>>>>    			  const struct mei_cl_device_id *id)  { diff --git
>>>> a/include/linux/mei_hdcp.h b/include/linux/mei_hdcp.h index
>>>> 9a869d1cbd5d..c333528b9c1e 100644
>>>> --- a/include/linux/mei_hdcp.h
>>>> +++ b/include/linux/mei_hdcp.h
>>>> @@ -24,6 +24,7 @@
>>>>    #define _LINUX_MEI_HDCP_H
>>>>
>>>>    #include <linux/mei_cl_bus.h>
>>>> +#include <drm/drm_hdcp.h>
>>>>
>>>>    /*
>>>>     * Enumeration of the physical DDI available on the platform @@
>>>> -101,6
>>>> +102,9 @@ int mei_hdcp_cldev_get_reference(void *client_data,
>>>>    						       struct mei_cl_device
>>>>    						       *cldev));
>>>>    void mei_hdcp_cldev_put_reference(struct mei_cl_device *cldev);
>>>> +
>>>> +int mei_initiate_hdcp2_session(struct mei_hdcp_data *data,
>>>> +			       struct hdcp2_ake_init *ake_data);
>>>>    #else
>>>>    static inline
>>>>    int mei_hdcp_cldev_get_reference(void *client_data, @@ -114,5
>>>> +118,12 @@ int mei_hdcp_cldev_get_reference(void *client_data,
>>>> static inline  void mei_hdcp_cldev_put_reference(struct mei_cl_device
>>>> *cldev)  {}
>>>> +
>>>> +static inline
>>>> +int mei_initiate_hdcp2_session(struct mei_hdcp_data *data,
>>>> +			       struct hdcp2_ake_init *ake_data) {
>>>> +	return -ENODEV;
>>>> +}
>>>>    #endif /* defined (CONFIG_INTEL_MEI_HDCP) */  #endif /* defined
>>>> (_LINUX_MEI_HDCP_H) */
>>>> --
>>>> 2.7.4

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