Re: usb raw gadget impossible to sent buffer bigger than 3MB

[Felipe Balbi <balbi@kernel.org>]

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Hi,

Belisko Marek <marek.belisko@gmail.com> writes:
>> >> Belisko Marek <marek.belisko@gmail.com> writes:
>> >> > we're using USB RAW gadget for communicating with PC application. We
>> >> > have created loopback test which send file (any size) from PC to
>> >> > device and then same data are sent back to PC to verify roundtrip time
>> >> > (using bulk data transfer). Everything works fine up to 3MB file size.
>> >> > If we sent bigger file like e.g. 5M we can receive file on device but
>> >> > when we want to write to output endpoint we got:
>> >> >
>> >> > WARNING: CPU: 0 PID: 12299 at /kernel-source//mm/page_alloc.c:3725
>> >> > __alloc_pages_nodemask+0x1b0/0xde4
>> >> > [<c010fa08>] (unwind_backtrace) from [<c010c45c>] (show_stack+0x20/0x24)
>> >> > [<c010c45c>] (show_stack) from [<c04cc0d4>] (dump_stack+0x20/0x28)
>> >> > [<c04cc0d4>] (dump_stack) from [<c01324ac>] (__warn+0xec/0x108)
>> >> > [<c01324ac>] (__warn) from [<c0132598>] (warn_slowpath_null+0x30/0x38)
>> >> > [<c0132598>] (warn_slowpath_null) from [<c021ccb8>]
>> >> > (__alloc_pages_nodemask+0x1b0/0xde4)
>> >> > [<c021ccb8>] (__alloc_pages_nodemask) from [<c023b888>]
>> >> > (kmalloc_order+0x2c/0x48)
>> >> > [<c023b888>] (kmalloc_order) from [<c023b8d0>] (kmalloc_order_trace+0x2c/0xd4)
>> >> > [<c023b8d0>] (kmalloc_order_trace) from [<c0261c24>] (__kmalloc+0x40/0x264)
>> >> > [<c0261c24>] (__kmalloc) from [<bf039bc4>] (ffs_epfile_io+0x13c/0x570
>> >> > [usb_f_fs])
>> >> > [<bf039bc4>] (ffs_epfile_io [usb_f_fs]) from [<bf03a0c0>]
>> >> > (ffs_epfile_write_iter+0xc8/0x120 [usb_f_fs])
>> >> > [<bf03a0c0>] (ffs_epfile_write_iter [usb_f_fs]) from [<c02734bc>]
>> >> > (new_sync_write+0xc8/0xec)
>> >> > [<c02734bc>] (new_sync_write) from [<c027351c>] (__vfs_write+0x3c/0x48)
>> >> > [<c027351c>] (__vfs_write) from [<c02749a0>] (vfs_write+0xcc/0x158)
>> >> > [<c02749a0>] (vfs_write) from [<c02756ac>] (SyS_write+0x50/0x88)
>> >> > [<c02756ac>] (SyS_write) from [<c0107a20>] (ret_fast_syscall+0x0/0x54)
>> >> > ---[ end trace fe5f79fe415b9881 ]---
>> >> >
>> >> > and write ends up with: write /run/ffs/ep1: cannot allocate memory
>> >> >
>> >> > When checked free command there should be plenty of available memory.
>> >> > Is there some limitation when writing to endpoint? We tried to split
>> >> > buffer to e.g. 3M and sent it and this works but looks like there is
>> >> > penalty when sending bigger files (100MB file received in 5secs whicle
>> >> > sending back it took 2minutes). Thanks for ideas and hints.
>> >>
>> >> that's trying to allocate a 5MiB buffer in kernel space. It just goes
>> >> over max allocation size, I'm assuming. Which kernel version are you
>> >> using? Which gadget controller are you using?
>> > We' using mainline 4.12 kernel and gadget is raw gadget using ffs +
>>
>> that's old. Really, really old. You should ask for support from whoever
>> gave you that kernel. An alternative, upgrade to v5.6 latest stable or
>> latest v5.7-rc.
> We're in the process of kernel bump (we really have no vendor kernel
> we use mainline with few patches on top)
>>
>> > composite drivers.
>>
>> Right, and which UDC controller?
> Not sure if it is right but those options are enabled:
> EHCI support for OMAP3 and later chips
> OHCI support for OMAP3 and later chips

those are host controllers :-) Are you running on OMAP3? If that's the
case, then you're using MUSB. Still, please give it a whirl with
something more recent just to rule out the possibility that the problem
hasn't already been fixed.

-- 
balbi

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