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

Large USB HID transfers

2013-10-31 Thread Cliff Brake
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 data is HID. We're noticing that when we transfer a lot of data over HID,