Commit 4fd99f67 authored by Lewis Huang's avatar Lewis Huang Committed by Alex Deucher
Browse files

drm/amd/display: refine i2c over aux 



[Why]
When user mode use i2c over aux through ADL or DDI, the function
dal_ddc_service_query_ddc_data will be called. There are two issues.

1. When read/write length > 16byte, current always return false because
the DEFAULT_AUX_MAX_DATA_SIZE != length.
2. When usermode only need to read data through i2c, driver will write
mot = true at the same address and cause i2c sink confused. Therefore
the following read command will get garbage.

[How]
1. Add function dal_dcc_submit_aux_command to handle length > 16 byte.
2. Check read size and write size when query ddc data.

Signed-off-by: default avatarLewis Huang <Lewis.Huang@amd.com>
Reviewed-by: default avatarCharlene Liu <Charlene.Liu@amd.com>
Acked-by: default avatarBhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 8ac64f0a

drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c

+60 −27
Original line number Diff line number Diff line
@@ -496,7 +496,7 @@ bool dal_ddc_service_query_ddc_data( 
	uint8_t *read_buf,

	uint32_t read_size)

{

	bool ret;

	bool ret = false;

	uint32_t payload_size =

		dal_ddc_service_is_in_aux_transaction_mode(ddc) ?

			DEFAULT_AUX_MAX_DATA_SIZE : EDID_SEGMENT_SIZE;
@@ -515,34 +515,32 @@ bool dal_ddc_service_query_ddc_data( 
	/*TODO: len of payload data for i2c and aux is uint8!!!!,

	 *  but we want to read 256 over i2c!!!!*/

	if (dal_ddc_service_is_in_aux_transaction_mode(ddc)) {

		struct aux_payload write_payload = {

			.i2c_over_aux = true,

			.write = true,

			.mot = true,

			.address = address,

			.length = write_size,

			.data = write_buf,

			.reply = NULL,

			.defer_delay = get_defer_delay(ddc),

		};

		struct aux_payload payload;

		bool read_available = true;



		struct aux_payload read_payload = {

			.i2c_over_aux = true,

			.write = false,

			.mot = false,

			.address = address,

			.length = read_size,

			.data = read_buf,

			.reply = NULL,

			.defer_delay = get_defer_delay(ddc),

		};

		payload.i2c_over_aux = true;

		payload.address = address;

		payload.reply = NULL;

		payload.defer_delay = get_defer_delay(ddc);



		ret = dc_link_aux_transfer_with_retries(ddc, &write_payload);

		if (write_size != 0) {

			payload.write = true;

			payload.mot = true;

			payload.length = write_size;

			payload.data = write_buf;



		if (!ret)

			return false;

			ret = dal_ddc_submit_aux_command(ddc, &payload);

			read_available = ret;

		}



		if (read_size != 0 && read_available) {

			payload.write = false;

			payload.mot = false;

			payload.length = read_size;

			payload.data = read_buf;



		ret = dc_link_aux_transfer_with_retries(ddc, &read_payload);

			ret = dal_ddc_submit_aux_command(ddc, &payload);

		}

	} else {

		struct i2c_payloads *payloads =

			dal_ddc_i2c_payloads_create(ddc->ctx, payloads_num);
@@ -573,6 +571,41 @@ bool dal_ddc_service_query_ddc_data( 
	return ret;

}



bool dal_ddc_submit_aux_command(struct ddc_service *ddc,

		struct aux_payload *payload)

{

	uint8_t retrieved = 0;

	bool ret = 0;



	if (!ddc)

		return false;



	if (!payload)

		return false;



	do {

		struct aux_payload current_payload;

		bool is_end_of_payload = (retrieved + DEFAULT_AUX_MAX_DATA_SIZE) >

			payload->length ? true : false;



		current_payload.address = payload->address;

		current_payload.data = &payload->data[retrieved];

		current_payload.defer_delay = payload->defer_delay;

		current_payload.i2c_over_aux = payload->i2c_over_aux;

		current_payload.length = is_end_of_payload ?

			payload->length - retrieved : DEFAULT_AUX_MAX_DATA_SIZE;

		current_payload.mot = payload->mot ? payload->mot : !is_end_of_payload;

		current_payload.reply = payload->reply;

		current_payload.write = payload->write;



		ret = dc_link_aux_transfer_with_retries(ddc, &current_payload);



		retrieved += current_payload.length;

	} while (retrieved < payload->length && ret == true);



	return ret;

}



/* dc_link_aux_transfer_raw() - Attempt to transfer

 * the given aux payload.  This function does not perform

 * retries or handle error states.  The reply is returned

drivers/gpu/drm/amd/display/dc/inc/dc_link_ddc.h

+3 −0
Original line number Diff line number Diff line
@@ -95,6 +95,9 @@ bool dal_ddc_service_query_ddc_data( 
		uint8_t *read_buf,

		uint32_t read_size);



bool dal_ddc_submit_aux_command(struct ddc_service *ddc,

		struct aux_payload *payload);



int dc_link_aux_transfer_raw(struct ddc_service *ddc,

		struct aux_payload *payload,

		enum aux_channel_operation_result *operation_result);

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