Belisko Marek <marek.belisko@gmail.com> writes:

> Hi,
> On Thu, May 28, 2020 at 11:06 AM Felipe Balbi <balbi@kernel.org> wrote:
>>
>>
>> Hi,
>>
>> 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.

> composite drivers.

Right, and which UDC controller?

-- 
balbi