[PATCH RESEND v7 02/10] drm/bridge: it6505: improve AUX operation for edid read

[Hermes Wu via B4 Relay]

From: Hermes Wu <hermes...@ite.com.tw>

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: Dmitry Baryshkov <dmitry.barysh...@linaro.org>
Signed-off-by: Hermes Wu <hermes...@ite.com.tw>
---
 drivers/gpu/drm/bridge/ite-it6505.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c 
b/drivers/gpu/drm/bridge/ite-it6505.c
index 
3272ca6951f2585f9592834869de23ac50ce41a4..9747d7ccf435d536da55c6a3ff79e504b7c724f0
 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -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);

-- 
2.34.1