[Help]"No space left on device." error exist when 2 webcams are plugged into same USB hub

Wong,

Which platform are you connecting the device to ? Are you connecting it  to OTG port of any TI platform ? Which linux kernel version are you using?

This looks like OTG port and improper FIFO table casuing this error.

Regards,

Ajay

Dear Ajay,

Thank you very much for your prompt reply. Could you please show me where I can configure the FIFO table?

FYI, I am using kernel 2.6.29

I am using DevKit8000 which is a compatible of  BeagleBoard. Here is the hardware information

Processor       : ARMv7 Processor rev 3 (v7l)
BogoMIPS        : 610.24
Features        : swp half thumb fastmult vfp edsp
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x1
CPU part        : 0xc08
CPU revision    : 3

Hardware        : OMAP3 Beagle Board
Revision        : 0020
Serial          : 0000000000000000

Regards,

Fai Wong

wong,

I am not yet sure if you are using OTG port (Mini-AB connector) or USBHOST port (standard PC like connector) for this testing.

If you are using OTG port for connecting two cameras then you can modify mode_4_cfg in drivers/usb/musb to have two FIFO_RX with 1024 size. Please make sure

that the sum of all FIFO sizes is less than 16KB-64B as total available FIFO is 16KB and 64 byte reserved for ep0. You can delete some of the endpoint entries also.

Regards,
Ajay

Dear Ajay,

I am using USBHOST port (standard PC like connector) for the testing. I suppose there should be a similar cfg file of FIFO_RX for HOSTUSB. Where is it please?

Regards,
Fai Wong

For USBHOST port this looks like some bug in EHCI stack. A simple below hack shoud help or move to latest kernel,

diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index a081ee6..dbab2a1 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -1222,7 +1222,7 @@ itd_slot_ok (
                /* can't commit more than 80% periodic == 100 usec */
                if (periodic_usecs (ehci, uframe >> 3, uframe & 0x7)
                                > (100 - usecs))
-                       return 0;
+                       return 1;

                /* we know urb->interval is 2^N uframes */
                uframe += period;

Regards,
Ajay

Dear Ajay,

Sorry, I don't understand what you are trying to tell me. Is there a FIFO_RX equivalent in the code of USB host?

Regards,

Fai Wong

Wong,

There is no FIFO table equivalent to OTG port for USBHOST ports. You can try the changes suggest in my earlier response and test.

Regards,
Ajay

Dear Ajay,

I found that I didn't compile this file before. Can you please tell me which option I should select in menuconfig when compiling the kernel?

Regards,
Fai Wong

It would definitely be getting compiled. It might be included in ehci-hcd.c as  ehci-sched.c for compilation.Please move to latest kernel or use the hack and see if it helps you.

Regards,

ajay