On 03/05/2016 06:34 AM, Daniel Vetter wrote:
> On Mon, Feb 29, 2016 at 03:02:09PM +0000, Chris Wilson wrote:
>> On Mon, Feb 29, 2016 at 03:54:19PM +0100, Daniel Vetter wrote:
>>> On Thu, Feb 25, 2016 at 06:01:22PM +0000, Chris Wilson wrote:
>>>> On Thu, Feb 11, 2016 at 08:04:51PM -0200, Tiago Vignatti wrote:
>>>>> +static long dma_buf_ioctl(struct file *file,
>>>>> + unsigned int cmd, unsigned long arg)
>>>>> +{
>>>>> + struct dma_buf *dmabuf;
>>>>> + struct dma_buf_sync sync;
>>>>> + enum dma_data_direction direction;
>>>>> +
>>>>> + dmabuf = file->private_data;
>>>>> +
>>>>> + switch (cmd) {
>>>>> + case DMA_BUF_IOCTL_SYNC:
>>>>> + if (copy_from_user(&sync, (void __user *) arg, sizeof(sync)))
>>>>> + return -EFAULT;
>>>>> +
>>>>> + if (sync.flags & ~DMA_BUF_SYNC_VALID_FLAGS_MASK)
>>>>> + return -EINVAL;
>>>>> +
>>>>> + switch (sync.flags & DMA_BUF_SYNC_RW) {
>>>>> + case DMA_BUF_SYNC_READ:
>>>>> + direction = DMA_FROM_DEVICE;
>>>>> + break;
>>>>> + case DMA_BUF_SYNC_WRITE:
>>>>> + direction = DMA_TO_DEVICE;
>>>>> + break;
>>>>> + case DMA_BUF_SYNC_RW:
>>>>> + direction = DMA_BIDIRECTIONAL;
>>>>> + break;
>>>>> + default:
>>>>> + return -EINVAL;
>>>>> + }
>>>>> +
>>>>> + if (sync.flags & DMA_BUF_SYNC_END)
>>>>> + dma_buf_end_cpu_access(dmabuf, direction);
>>>>> + else
>>>>> + dma_buf_begin_cpu_access(dmabuf, direction);
>>>>
>>>> We forgot to report the error back to userspace. Might as well fixup the
>>>> callchain to propagate error from end-cpu-access as well. Found after
>>>> updating igt/gem_concurrent_blit to exercise dmabuf mmaps vs the GPU.
>>>
>>> EINTR? Do we need to make this ABI - I guess so? Tiago, do you have
>>> patches? See drmIoctl() in libdrm for what's needed on the userspace side
>>> if my guess is right.
>>
>> EINTR is the easiest, but conceivably we could also get EIO and
>> currently EAGAIN.
>>
>> I am also seeing some strange timing dependent (i.e. valgrind doesn't
>> show up anything client side and the tests then pass) failures (SIGSEGV,
>> SIGBUS) with !llc.
>
> Tiago, ping. Also probably a gap in igt coverage besides the kernel side.
> -Daniel
Hey guys! I'm back from vacation now. I'll take a look on it in the next
days and then come back to you.
Tiago
