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Commit 1a43e709 authored by Tatenda Chipeperekwa's avatar Tatenda Chipeperekwa Committed by Gerrit - the friendly Code Review server
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drm/msm/dp: fix EDID read for non-compliant sinks 



Fix EDID read for non-compliant sinks that do not
handle the i2c middle-of-transaction flag correctly.

CRs-Fixed: 2105346
Change-Id: I6f3fb67d81e082ff212188d933d42ac82825f764
Signed-off-by: default avatarTatenda Chipeperekwa <tatendac@codeaurora.org>
parent 504e2895

drivers/gpu/drm/msm/dp/dp_aux.c

+93 −4
Original line number Diff line number Diff line
@@ -40,6 +40,8 @@ struct dp_aux_private { 
	bool read;

	bool no_send_addr;

	bool no_send_stop;

	u32 offset;

	u32 segment;



	struct drm_dp_aux drm_aux;

};
@@ -104,6 +106,8 @@ static u32 dp_aux_write(struct dp_aux_private *aux, 
		aux->catalog->write_data(aux->catalog);

	}



	aux->catalog->clear_trans(aux->catalog, false);



	reg = 0; /* Transaction number == 1 */

	if (!aux->native) { /* i2c */

		reg |= BIT(8);
@@ -162,6 +166,8 @@ static void dp_aux_cmd_fifo_rx(struct dp_aux_private *aux, 
	u32 i, actual_i;

	u32 len = msg->size;



	aux->catalog->clear_trans(aux->catalog, true);



	data = 0;

	data |= DP_AUX_DATA_INDEX_WRITE; /* INDEX_WRITE */

	data |= BIT(0);  /* read */
@@ -264,6 +270,87 @@ static void dp_aux_reconfig(struct dp_aux *dp_aux) 
	aux->catalog->reset(aux->catalog);

}



static void dp_aux_update_offset_and_segment(struct dp_aux_private *aux,

		struct drm_dp_aux_msg *input_msg)

{

	u32 const edid_address = 0x50;

	u32 const segment_address = 0x30;

	bool i2c_read = input_msg->request &

		(DP_AUX_I2C_READ & DP_AUX_NATIVE_READ);

	u8 *data = NULL;



	if (aux->native || i2c_read || ((input_msg->address != edid_address) &&

		(input_msg->address != segment_address)))

		return;





	data = input_msg->buffer;

	if (input_msg->address == segment_address)

		aux->segment = *data;

	else

		aux->offset = *data;

}



/**

 * dp_aux_transfer_helper() - helper function for EDID read transactions

 *

 * @aux: DP AUX private structure

 * @input_msg: input message from DRM upstream APIs

 *

 * return: void

 *

 * This helper function is used to fix EDID reads for non-compliant

 * sinks that do not handle the i2c middle-of-transaction flag correctly.

 */

static void dp_aux_transfer_helper(struct dp_aux_private *aux,

		struct drm_dp_aux_msg *input_msg)

{

	struct drm_dp_aux_msg helper_msg;

	u32 const message_size = 0x10;

	u32 const segment_address = 0x30;

	bool i2c_mot = input_msg->request & DP_AUX_I2C_MOT;

	bool i2c_read = input_msg->request &

		(DP_AUX_I2C_READ & DP_AUX_NATIVE_READ);



	if (!i2c_mot || !i2c_read || (input_msg->size == 0))

		return;



	aux->read = false;

	aux->cmd_busy = true;

	aux->no_send_addr = true;

	aux->no_send_stop = true;



	/*

	 * Send the segment address for every i2c read in which the

	 * middle-of-tranaction flag is set. This is required to support EDID

	 * reads of more than 2 blocks as the segment address is reset to 0

	 * since we are overriding the middle-of-transaction flag for read

	 * transactions.

	 */

	memset(&helper_msg, 0, sizeof(helper_msg));

	helper_msg.address = segment_address;

	helper_msg.buffer = &aux->segment;

	helper_msg.size = 1;

	dp_aux_cmd_fifo_tx(aux, &helper_msg);



	/*

	 * Send the offset address for every i2c read in which the

	 * middle-of-transaction flag is set. This will ensure that the sink

	 * will update its read pointer and return the correct portion of the

	 * EDID buffer in the subsequent i2c read trasntion triggered in the

	 * native AUX transfer function.

	 */

	memset(&helper_msg, 0, sizeof(helper_msg));

	helper_msg.address = input_msg->address;

	helper_msg.buffer = &aux->offset;

	helper_msg.size = 1;

	dp_aux_cmd_fifo_tx(aux, &helper_msg);

	aux->offset += message_size;



	if (aux->offset == 0x80 || aux->offset == 0x100)

		aux->segment = 0x0; /* reset segment at end of block */

}



/*

 * This function does the real job to process an AUX transaction.

 * It will call aux_reset() function to reset the AUX channel,
@@ -282,8 +369,6 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux *drm_aux, 
	mutex_lock(&aux->mutex);



	aux->native = msg->request & (DP_AUX_NATIVE_WRITE & DP_AUX_NATIVE_READ);

	aux->read = msg->request & (DP_AUX_I2C_READ & DP_AUX_NATIVE_READ);

	aux->cmd_busy = true;



	/* Ignore address only message */

	if ((msg->size == 0) || (msg->buffer == NULL)) {
@@ -302,6 +387,12 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux *drm_aux, 
		goto unlock_exit;

	}



	dp_aux_update_offset_and_segment(aux, msg);

	dp_aux_transfer_helper(aux, msg);



	aux->read = msg->request & (DP_AUX_I2C_READ & DP_AUX_NATIVE_READ);

	aux->cmd_busy = true;



	if (aux->read) {

		aux->no_send_addr = true;

		aux->no_send_stop = false;
@@ -322,8 +413,6 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux *drm_aux, 
		goto unlock_exit;

	}



	aux->catalog->clear_trans(aux->catalog);



	if (aux->aux_error_num == DP_AUX_ERR_NONE) {

		if (aux->read)

			dp_aux_cmd_fifo_rx(aux, msg);

drivers/gpu/drm/msm/dp/dp_catalog.c

+9 −8
Original line number Diff line number Diff line
@@ -131,10 +131,10 @@ static int dp_catalog_aux_write_trans(struct dp_catalog_aux *aux) 
	return rc;

}



static int dp_catalog_aux_clear_trans(struct dp_catalog_aux *aux)

static int dp_catalog_aux_clear_trans(struct dp_catalog_aux *aux, bool read)

{

	int rc = 0;

	u32 data;

	u32 data = 0;

	struct dp_catalog_private *catalog;

	void __iomem *base;
@@ -147,9 +147,13 @@ static int dp_catalog_aux_clear_trans(struct dp_catalog_aux *aux) 
	dp_catalog_get_priv(aux);

	base = catalog->io->ctrl_io.base;



	if (read) {

		data = dp_read(base + DP_AUX_TRANS_CTRL);

		data &= ~BIT(9);

		dp_write(base + DP_AUX_TRANS_CTRL, data);

	} else {

		dp_write(base + DP_AUX_TRANS_CTRL, 0);

	}

end:

	return rc;

}
@@ -275,9 +279,6 @@ static void dp_catalog_aux_get_irq(struct dp_catalog_aux *aux, bool cmd_busy) 
	dp_catalog_get_priv(aux);

	base = catalog->io->ctrl_io.base;



	if (cmd_busy)

		dp_write(base + DP_AUX_TRANS_CTRL, 0x0);



	aux->isr = dp_read(base + DP_INTR_STATUS);

	aux->isr &= ~DP_INTR_MASK1;

	ack = aux->isr & DP_INTERRUPT_STATUS1;

drivers/gpu/drm/msm/dp/dp_catalog.h

+1 −1
Original line number Diff line number Diff line
@@ -67,7 +67,7 @@ struct dp_catalog_aux { 
	u32 (*read_data)(struct dp_catalog_aux *aux);

	int (*write_data)(struct dp_catalog_aux *aux);

	int (*write_trans)(struct dp_catalog_aux *aux);

	int (*clear_trans)(struct dp_catalog_aux *aux);

	int (*clear_trans)(struct dp_catalog_aux *aux, bool read);

	void (*reset)(struct dp_catalog_aux *aux);

	void (*enable)(struct dp_catalog_aux *aux, bool enable);

	void (*update_aux_cfg)(struct dp_catalog_aux *aux,