HD4400 clEnqueueCopyBufferRect issue?

[Vladimir_D_Intel1]

Hello,

we've detected suspicious behaviour of clEnqueueWriteBufferRect/clEnqueueCopyBufferRect functions which is demonstrated with simple test case attached. The test case depends on OpenCL API only. This work correctly on AMD Tahiti but not on Intel HD4400, HD4600.

The problem is in copying rectangle of interest with some specific parameters from whole image, which is kept in cl buffer.

The short description of test case:

1. create opencl buffer for whole image (not initialized)

2. copy to this buffer data a from aligned host memory rectangle with some specific parameters (using clEnqueueWriteBufferRect)

3. create opencl buffer for size of rectangle used on previous step (not initialized)

4. copy gpu data for the rectangle from whole image cl buffer to this rectangle-only cl buffer (using clEnqueueCopyBufferRect)

5. map rectangle-only cl buffer to host memory

6. compare content of original host data for rectangle with content of this mapped memory. It is expected to be exactly the same but it is not on our environment (HD4400).

Below is sample output

on AMD system:

C:\project\vdudnik\iocl-bug\build\Debug>iocl-bug.exe

AMD Accelerated Parallel Processing

OpenCL 1.2 AMD-APP (1445.5)

Advanced Micro Devices, Inc.

Tahiti

no mismatch found, test PASSED

on Intel system:

C:\dev\iocl-bug\build\Debug>iocl-bug.exe

Intel(R) OpenCL

OpenCL 1.2

Intel(R) Corporation

Intel(R) HD Graphics 4400

detetcted mismatch: [ 0 X 1 ], expected = 4, actual = 55

detetcted mismatch: [ 1 X 1 ], expected = 4, actual = 55

detetcted mismatch: [ 2 X 1 ], expected = 4, actual = 55

detetcted mismatch: [ 3 X 1 ], expected = 4, actual = 55

detetcted mismatch: [ 4 X 1 ], expected = 4, actual = 55

detetcted mismatch: [ 0 X 2 ], expected = 4, actual = 55

detetcted mismatch: [ 1 X 2 ], expected = 4, actual = 55

detetcted mismatch: [ 2 X 2 ], expected = 4, actual = 55

detetcted mismatch: [ 3 X 2 ], expected = 4, actual = 55

detetcted mismatch: [ 4 X 2 ], expected = 4, actual = 55

detetcted mismatch: [ 5 X 2 ], expected = 4, actual = 55

detetcted mismatch: [ 6 X 2 ], expected = 4, actual = 0

detetcted mismatch: [ 7 X 2 ], expected = 4, actual = 0

show only few first mismatches.., test FAILED

To build this test case CMake 3.1+ is required.

Regards,
  Vladimir

[Robert_I_Intel]

Hi Vladimir,

Before I attempt to reproduce this, couple of questions:

1. What OS version are you using?

2. What version of the graphics driver are you using?

[Vladimir_D_Intel1]

Hi Robert,

We've used Windows 7 Service Pack 1, x64

Video driver version is 10.18.14.4139 WHQL Win7 64

Regards,
  Vladimir
 

[Robert_I_Intel]

Hi Vladimir,

I just reproduced your problem on a newer driver and OS. I will take a closer look at the code and file a bug if there is an issue on our side. Thank you for reporting this problem!

[Vladimir_D_Intel1]

Ok, thanks.