Hello Mr. Torokhov,

Could you kindly help to update about this patch?

Thank you,
Aniroop Mathur


On Fri, Mar 11, 2016 at 12:26 AM, Aniroop Mathur
[off-list ref] wrote:

Hi Henrik,

On Thu, Mar 10, 2016 at 7:15 PM, Henrik Rydberg [off-list ref] wrote:

quoted

Hi Dmitry,

quoted

quoted

diff --git a/drivers/input/input.c b/drivers/input/input.c
index 8806059..262ef77 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c

@@ -401,8 +401,7 @@ static void input_handle_event(struct input_dev *dev,
                if (dev->num_vals >= 2)
                        input_pass_values(dev, dev->vals, dev->num_vals);
                dev->num_vals = 0;
-       } else if (dev->num_vals >= dev->max_vals - 2) {
-               dev->vals[dev->num_vals++] = input_value_sync;
+       } else if (dev->num_vals >= dev->max_vals - 1) {
                input_pass_values(dev, dev->vals, dev->num_vals);
                dev->num_vals = 0;
        }

This makes sense to me. Henrik?

I went through the commits that made these changes, and I cannot see any strong
reason to keep it. However, this code path only triggers if no SYN events are
seen, as in a driver that fails to emit them and consequently fills up the
buffer. In other words, this change would only affect a device that is already,
to some degree, broken.

So, the question to Aniroop is: do you see this problem in practise, and in that
case, for what driver?

Nope. So far I have not dealt with any such driver.
I made this change because it is breaking protocol of SYN_REPORT event code.

Further from the code, I could deduce that max_vals is just an estimation of
packet_size and it does not guarantee that packet_size is same as max_vals.
So real packet_size can be more than max_vals value and hence we could not
insert SYN_REPORT until packet ends really.
Further, if we consider that there exists a driver or will exist in future
which sets capability of x event code according to which max_value comes out to
y and the real packet size is z i.e. driver wants to send same event codes
again in the same packet, so input event reader would be expecting SYN_REPORT
after z events but due to current code SYN_REPORT will get inserted
automatically after y events, which is a wrong behaviour.

Thanks,
Aniroop Mathur

quoted

Henrik