Re: Large USB HID transfers

2013-11-07 Thread Cliff Brake
On Thu, Nov 7, 2013 at 12:47 PM, Alan Ott wrote: > On 11/05/2013 05:39 PM, Cliff Brake wrote: >> >> On Tue, Nov 5, 2013 at 9:57 AM, Alan Stern >> wrote: >>> >>> You might be better off writing a special-purpose userspace driver, using >>> libusb, instead of relying on the HID driver. That would a

Re: Large USB HID transfers

2013-11-07 Thread Alan Ott
On 11/05/2013 05:39 PM, Cliff Brake wrote: On Tue, Nov 5, 2013 at 9:57 AM, Alan Stern wrote: You might be better off writing a special-purpose userspace driver, using libusb, instead of relying on the HID driver. That would allow you to handle your data more efficiently, and with interrupts en

Re: Large USB HID transfers

2013-11-06 Thread Alan Stern
On Tue, 5 Nov 2013, Cliff Brake wrote: > On Tue, Nov 5, 2013 at 9:57 AM, Alan Stern wrote: > > On Mon, 4 Nov 2013, Cliff Brake wrote: > > > > >> > >> I assume interrupts are disabled during both ohci_irq() and ehci_irq(). > > > > Currently they are. This will change somewhat in the not-too-dist

Re: Large USB HID transfers

2013-11-05 Thread Cliff Brake
On Tue, Nov 5, 2013 at 9:57 AM, Alan Stern wrote: > On Mon, 4 Nov 2013, Cliff Brake wrote: > >> >> I assume interrupts are disabled during both ohci_irq() and ehci_irq(). > > Currently they are. This will change somewhat in the not-too-distant > future. Are there any patches available yet for t

Re: Large USB HID transfers

2013-11-05 Thread Alan Stern
On Mon, 4 Nov 2013, Cliff Brake wrote: > On Mon, Nov 4, 2013 at 11:51 AM, Alan Stern wrote: > > On Mon, 4 Nov 2013, Cliff Brake wrote: > > >> We have the same system running on a older PXA270 version of the > >> product (vs the current TI DM3730). It has an older OHCI 12Mbit USB > >> host contr

Re: Large USB HID transfers

2013-11-04 Thread Cliff Brake
On Mon, Nov 4, 2013 at 11:51 AM, Alan Stern wrote: > On Mon, 4 Nov 2013, Cliff Brake wrote: >> We have the same system running on a older PXA270 version of the >> product (vs the current TI DM3730). It has an older OHCI 12Mbit USB >> host controller (vs the current TI EHCI controller). We have

Re: Large USB HID transfers

2013-11-04 Thread Alan Stern
On Mon, 4 Nov 2013, Cliff Brake wrote: > > As far as I can tell, the big blockage occurs when the machine has to > > analyze an input report from which it extracts 767 fields and ends up > > calling hid_process_event about 2300 times. Since each call takes > > around 60-80 microseconds, you end u

Re: Large USB HID transfers

2013-11-04 Thread Cliff Brake
On Fri, Nov 1, 2013 at 5:04 PM, Alan Stern wrote: > On Fri, 1 Nov 2013, Cliff Brake wrote: > >> On Thu, Oct 31, 2013 at 2:25 PM, Alan Stern >> wrote: >> >> >> > What host controller driver are you using? >> >> >> >> Its the USB EHCI host in the TI DM3730, so it uses the >> >> drivers/usb/host/eh

Re: Large USB HID transfers

2013-11-01 Thread Alan Stern
On Fri, 1 Nov 2013, Cliff Brake wrote: > On Thu, Oct 31, 2013 at 2:25 PM, Alan Stern wrote: > > >> > What host controller driver are you using? > >> > >> Its the USB EHCI host in the TI DM3730, so it uses the > >> drivers/usb/host/ehci-omap.c driver. > > > > You can find out exactly what part of

Re: Large USB HID transfers

2013-11-01 Thread Cliff Brake
On Thu, Oct 31, 2013 at 2:25 PM, Alan Stern wrote: >> > What host controller driver are you using? >> >> Its the USB EHCI host in the TI DM3730, so it uses the >> drivers/usb/host/ehci-omap.c driver. > > You can find out exactly what part of the kernel is responsible for > interrupt delays by usi

Re: Large USB HID transfers

2013-10-31 Thread Cliff Brake
On Thu, Oct 31, 2013 at 2:25 PM, Alan Stern wrote: > On Thu, 31 Oct 2013, Cliff Brake wrote: > >> On Thu, Oct 31, 2013 at 1:54 PM, Greg KH wrote: >> >> > Ick, that's not good. This sounds like a driver issue, if you can find >> > out where interrupts are being held for so long, hopefully a fix c

Re: Large USB HID transfers

2013-10-31 Thread Alan Stern
On Thu, 31 Oct 2013, Cliff Brake wrote: > On Thu, Oct 31, 2013 at 1:54 PM, Greg KH wrote: > > > Ick, that's not good. This sounds like a driver issue, if you can find > > out where interrupts are being held for so long, hopefully a fix can be > > found and resolved. It's good that 3.11 is bett

Re: Large USB HID transfers

2013-10-31 Thread Cliff Brake
On Thu, Oct 31, 2013 at 1:54 PM, Greg KH wrote: > Ick, that's not good. This sounds like a driver issue, if you can find > out where interrupts are being held for so long, hopefully a fix can be > found and resolved. It's good that 3.11 is better, but ideally a real > fix can be created. > > Wh

Re: Large USB HID transfers

2013-10-31 Thread Greg KH
On Thu, Oct 31, 2013 at 12:09:54PM -0400, Cliff Brake wrote: > On Thu, Oct 31, 2013 at 11:56 AM, Greg KH wrote: > > On Thu, Oct 31, 2013 at 11:24:05AM -0400, Cliff Brake wrote: > > > > I'd focus on the host controller driver, it would be the one that is > > probably the issue (you can test this wi

Re: Large USB HID transfers

2013-10-31 Thread Cliff Brake
On Thu, Oct 31, 2013 at 11:56 AM, Greg KH wrote: > On Thu, Oct 31, 2013 at 11:24:05AM -0400, Cliff Brake wrote: > > I'd focus on the host controller driver, it would be the one that is > probably the issue (you can test this with a PC running Linux and a > different host controller.) Thanks for t

Re: Large USB HID transfers

2013-10-31 Thread Greg KH
On Thu, Oct 31, 2013 at 11:24:05AM -0400, Cliff Brake wrote: > Hello, > > We are using a linux device as a iPad MFI peripheral. In the current > scenario, the iPad is the USB device, and linux system is the host. > With Apple MFI in this configuration, the only protocol available to > transfer da