Re: USB transfers in device drivers

2019-05-03 Thread O'Connor, Daniel
> On 3 May 2019, at 02:31, Hans Petter Selasky wrote: > > On 2019-05-02 13:38, O'Connor, Daniel wrote: >>> On 2 May 2019, at 20:33, Hans Petter Selasky wrote: >>> >>> On 2019-05-02 12:44, O'Connor, Daniel wrote: > On 2 May 2019, at 20:02, Hans Petter Selasky wrote: > > On

Re: USB transfers in device drivers

2019-05-02 Thread Hans Petter Selasky
On 2019-05-02 13:38, O'Connor, Daniel wrote: On 2 May 2019, at 20:33, Hans Petter Selasky wrote: On 2019-05-02 12:44, O'Connor, Daniel wrote: On 2 May 2019, at 20:02, Hans Petter Selasky wrote: On 2019-05-02 11:18, O'Connor, Daniel wrote: OK, thanks. To be honest I would much prefer to

Re: USB transfers in device drivers

2019-05-02 Thread O'Connor, Daniel
> On 2 May 2019, at 20:33, Hans Petter Selasky wrote: > > On 2019-05-02 12:44, O'Connor, Daniel wrote: >>> On 2 May 2019, at 20:02, Hans Petter Selasky wrote: >>> >>> On 2019-05-02 11:18, O'Connor, Daniel wrote: OK, thanks. To be honest I would much prefer to work out why this

Re: USB transfers in device drivers

2019-05-02 Thread Hans Petter Selasky
On 2019-05-02 12:44, O'Connor, Daniel wrote: On 2 May 2019, at 20:02, Hans Petter Selasky wrote: On 2019-05-02 11:18, O'Connor, Daniel wrote: OK, thanks. To be honest I would much prefer to work out why this particular hardware & software seem to drop the ball for such a long time -

Re: USB transfers in device drivers

2019-05-02 Thread O'Connor, Daniel
> On 2 May 2019, at 20:02, Hans Petter Selasky wrote: > > On 2019-05-02 11:18, O'Connor, Daniel wrote: >> OK, thanks. >> To be honest I would much prefer to work out why this particular hardware & >> software seem to drop the ball for such a long time - 50msec without the >> kernel getting

Re: USB transfers in device drivers

2019-05-02 Thread Hans Petter Selasky
On 2019-05-02 11:18, O'Connor, Daniel wrote: OK, thanks. To be honest I would much prefer to work out why this particular hardware & software seem to drop the ball for such a long time - 50msec without the kernel getting to schedule something (on a basically idle system) is quite perplexing to

Re: USB transfers in device drivers

2019-05-02 Thread O'Connor, Daniel
> On 2 May 2019, at 18:06, Hans Petter Selasky wrote: > On 2019-05-02 10:22, O'Connor, Daniel wrote: >>> On 2 May 2019, at 06:15, Hans Petter Selasky wrote: >>> On 2019-05-01 10:34, O'Connor, Daniel wrote: I don't have a solid hypothesis for the failures as yes but one thing I'd

Re: USB transfers in device drivers

2019-05-02 Thread Hans Petter Selasky
On 2019-05-02 10:22, O'Connor, Daniel wrote: On 2 May 2019, at 06:15, Hans Petter Selasky wrote: On 2019-05-01 10:34, O'Connor, Daniel wrote: I don't have a solid hypothesis for the failures as yes but one thing I'd like to make sure is that the USB stack is keeping the USB hardware busy

Re: USB transfers in device drivers

2019-05-02 Thread O'Connor, Daniel
> On 2 May 2019, at 06:15, Hans Petter Selasky wrote: > On 2019-05-01 10:34, O'Connor, Daniel wrote: >> I don't have a solid hypothesis for the failures as yes but one thing I'd >> like to make sure is that the USB stack is keeping the USB hardware busy >> with pending requests - does anyone

Re: USB transfers in device drivers

2019-05-01 Thread Hans Petter Selasky
On 2019-05-01 10:34, O'Connor, Daniel wrote: I don't have a solid hypothesis for the failures as yes but one thing I'd like to make sure is that the USB stack is keeping the USB hardware busy with pending requests - does anyone know if the USB FIFO code does that automatically? Only the

USB transfers in device drivers

2019-05-01 Thread O'Connor, Daniel
Hi, I have a device driver for a USB device (a custom Cypress FX2 based board) that is relatively simple - it uses the USB FIFO code to create 3 FIFOs (one bidirectional slow serial interface, one device->PC fast parallel interface from a hardware FIFO) plus a bunch of ioctls for getting the