Hi Dmitry!

First: THANKS for fixing my driver.
Second: sorry for slow answer :(

On Thu, Apr 23, 2020 at 4:05 AM Dmitry Torokhov
[off-list ref] wrote:

quoted

+config TOUCHSCREEN_CY8CTMA140
+     tristate "cy8ctma140 touchscreen"
+     depends on I2C
+     depends on GPIOLIB || COMPILE_TEST

Why do we need gpiolib here?

Not really. Dropped it.

quoted

+     ret = __i2c_transfer(ts->client->adapter, msg, ARRAY_SIZE(msg));

Why do we use "unlocked" __i2c_transfer()? Can't we use normal
i2c_transfer()? For __i2c_transfer() someone has to lock the segment...

Good point. Your patch works fine here.

Hmm, I think if we do use loop the code is actually _much_ simpler,
please see the patch below.

Indeed. Works like a charm after some fixes.

quoted

+     addr[0] = CY8CTMA140_GET_FW_INFO;
+     ret = i2c_master_send(ts->client, addr, 1);
+     if (ret < 0) {
+             dev_err(ts->dev, "error sending FW info message\n");
+             return ret;
+     }
+     ret = i2c_master_recv(ts->client, buf, 5);
+     if (ret < 0) {
+             dev_err(ts->dev, "error recieveing FW info message\n");
+             return ret;
+     }

Does it have to be 2 separate transactions? Can we use write/read
i2c_transfer() here?

I think it is necessary for the FW info test, this is not a standard
I2C transaction, notice that addr[0] does not contain the I2C
address of the device.

I tried to do it some other way but this was the
only way I could get it to work and detect the device properly.

Can you please try the patch below on top of yours?

Folded it in and will resend with my changes as v6.

This didn't work as i2c_master_send() returns the number of
bytes sent. I reverted this function back to using ret.

After that everything started to work!

Yours,
Linus Walleij