Commit d0c97a51 authored by Hermes Wu's avatar Hermes Wu Committed by Dmitry Baryshkov
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drm/bridge: it6505: improve AUX operation for edid read 



The original AUX operation using data registers is limited to 4 bytes.
The AUX operation command CMD_AUX_I2C_EDID_READ uses AUX FIFO and
is capable of reading 16 bytes.
This improves the speed of EDID read.

Reviewed-by: default avatarDmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: default avatarHermes Wu <hermes.wu@ite.com.tw>
Reviewed-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: default avatarDmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20241230-v7-upstream-v7-2-e0fdd4844703@ite.corp-partner.google.com
parent c1487021

drivers/gpu/drm/bridge/ite-it6505.c

+7 −3
Original line number Diff line number Diff line
@@ -1076,10 +1076,13 @@ static ssize_t it6505_aux_do_transfer(struct it6505 *it6505, 
				      size_t size, enum aux_cmd_reply *reply)

{

	int i, ret_size, ret = 0, request_size;

	int fifo_max_size = (cmd == CMD_AUX_I2C_EDID_READ) ? AUX_FIFO_MAX_SIZE : 4;



	mutex_lock(&it6505->aux_lock);

	for (i = 0; i < size; i += 4) {

		request_size = min((int)size - i, 4);

	i = 0;

	do {

		request_size = min_t(int, (int)size - i, fifo_max_size);



		ret_size = it6505_aux_operation(it6505, cmd, address + i,

						buffer + i, request_size,

						reply);
@@ -1088,8 +1091,9 @@ static ssize_t it6505_aux_do_transfer(struct it6505 *it6505, 
			goto aux_op_err;

		}



		i += request_size;

		ret += ret_size;

	}

	} while (i < size);



aux_op_err:

	mutex_unlock(&it6505->aux_lock);