(gdb) frame 3 #3 musb_host_rx (musb=0xdb3e0010, epnum=<optimized out>) at ../drivers/usb/musb/musb_host.c:1969 1969 done = musb_rx_dma_inventra_cppi41(c, hw_ep, qh, urb, xfer_len); (gdb) info locals hw_ep = 0xdb3e0f48 c = <optimized out> epio = <optimized out> qh = 0xd9cb2000 xfer_len = <optimized out> mbase = <optimized out> iso_err = <optimized out> done = <optimized out> status = <optimized out> dma = <optimized out> __func__ = <error reading variable __func__ (Cannot access memory at address 0x3e8)> (gdb) print hw_ep $21 = (struct musb_hw_ep *) 0xdb3e0f48 (gdb) print *hw_ep $22 = {musb = 0xdb3e0010, fifo = 0xe0bf6c58, regs = 0xe0bf6c10, epnum = 14 '\016', is_shared_fifo = true, tx_double_buffered = false, rx_double_buffered = false, max_packet_sz_tx = 1024, max_packet_sz_rx = 1024, tx_channel = 0x0, rx_channel = 0xd914c3bc, in_qh = 0xd9cb2000, out_qh = 0xd9cb2000, rx_reinit = 0 '\000', tx_reinit = 1 '\001', ep_in = {end_point = {driver_data = 0x0, name = 0x0, ops = 0x0, ep_list = {next = 0x0, prev = 0x0}, caps = {type_control = 0, type_iso = 0, type_bulk = 0, type_int = 0, dir_in = 0, dir_out = 0}, claimed = false, enabled = false, maxpacket = 0, maxpacket_limit = 0, max_streams = 0, mult = 0, maxburst = 0, address = 0 '\000', desc = 0x0, comp_desc = 0x0}, name = '\000' <repeats 11 times>, hw_ep = 0x0, musb = 0x0, current_epnum = 0 '\000', type = 0 '\000', is_in = 0 '\000', packet_sz = 0, desc = 0x0, dma = 0x0, req_list = {next = 0x0, prev = 0x0}, wedged = 0 '\000', busy = 0 '\000', hb_mult = 0 '\000'}, ep_out = {end_point = {driver_data = 0x0, name = 0x0, ops = 0x0, ep_list = {next = 0x0, prev = 0x0}, caps = {type_control = 0, type_iso = 0, type_bulk = 0, type_int = 0, dir_in = 0, dir_out = 0}, claimed = false, enabled = false, maxpacket = 0, maxpacket_limit = 0, max_streams = 0, mult = 0, maxburst = 0, address = 0 '\000', desc = 0x0, comp_desc = 0x0}, name = '\000' <repeats 11 times>, hw_ep = 0x0, musb = 0x0, current_epnum = 0 '\000', type = 0 '\000', is_in = 0 '\000', packet_sz = 0, desc = 0x0, dma = 0x0, req_list = {next = 0x0, prev = 0x0}, wedged = 0 '\000', busy = 0 '\000', hb_mult = 0 '\000'}} 2016-05-20 23:55 GMT+03:00 Matwey V. Kornilov <matwey@xxxxxxxxxx>: > I used kgdb. Is it ok? > channel appeared to be 0x0: > > (gdb) continue > Continuing. > [Switching to Thread 315] > > Breakpoint 1, cppi41_dma_channel_program (channel=0x0, packet_sz=960, > mode=0 '\000', dma_addr=2609136576, len=960) > at ../drivers/usb/musb/musb_cppi41.c:481 > 481 { > (gdb) bt > #0 cppi41_dma_channel_program (channel=0x0, packet_sz=960, mode=0 > '\000', dma_addr=2609136576, len=960) > at ../drivers/usb/musb/musb_cppi41.c:481 > #1 0xbf251570 in musb_rx_dma_iso_cppi41 (len=<optimized out>, > urb=<optimized out>, qh=<optimized out>, hw_ep=<optimized out>, > dma=<optimized out>) at ../drivers/usb/musb/musb_host.c:1569 > #2 musb_rx_dma_inventra_cppi41 (len=<optimized out>, urb=<optimized > out>, qh=<optimized out>, hw_ep=<optimized out>, > dma=<optimized out>) at ../drivers/usb/musb/musb_host.c:1652 > #3 musb_host_rx (musb=0xdb3e0010, epnum=<optimized out>) at > ../drivers/usb/musb/musb_host.c:1969 > #4 0xbf249fb4 in musb_dma_completion (musb=<optimized out>, > epnum=<optimized out>, transmit=<optimized out>) > at ../drivers/usb/musb/musb_core.c:1693 > #5 0xbf258b10 in cppi41_trans_done (cppi41_channel=0xd914c3bc) at > ../drivers/usb/musb/musb_cppi41.c:148 > #6 0xbf258c1c in cppi41_dma_callback (private_data=<optimized out>) > at ../drivers/usb/musb/musb_cppi41.c:286 > #7 0xbf229f38 in ?? () > Backtrace stopped: previous frame identical to this frame (corrupt stack?) > > > 2016-05-20 23:10 GMT+03:00 Bin Liu <b-liu@xxxxxx>: >> Hi, >> >> On Fri, May 20, 2016 at 04:32:06PM +0300, Matwey V. Kornilov wrote: >>> 2016-05-20 16:19 GMT+03:00 <matwey@xxxxxxxxxx>: >>> > Hello, >>> > >>> > I am running 4.6-rc3 on BealgeBone Black and when I try to interract >>> > with pwc webcam attached to usb port the following kernel panic >>> > happening. >>> >>> Please note, that the same is happening with 4.6.0 release. >> >> Please apply the following patch and reproduce the oops, I'd like to >> check if the oops is caused by NULL of hw_ep->in_qh. >> >> Regards, >> -Bin. >> >> ---8<------- >> diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c >> index e499b86..3492c6e 100644 >> --- a/drivers/usb/musb/musb_cppi41.c >> +++ b/drivers/usb/musb/musb_cppi41.c >> @@ -489,8 +489,11 @@ static int cppi41_dma_channel_program(struct dma_channel *channel, >> if (is_host_active(cppi41_channel->controller->musb)) { >> if (cppi41_channel->is_tx) >> hb_mult = cppi41_channel->hw_ep->out_qh->hb_mult; >> - else >> + else { >> + if (!cppi41_channel->hw_ep->in_qh) >> + dev_err(NULL, "->in_qh is NULL\n"); >> hb_mult = cppi41_channel->hw_ep->in_qh->hb_mult; >> + } >> } >> >> channel->status = MUSB_DMA_STATUS_BUSY; >> > > > > -- > With best regards, > Matwey V. Kornilov. > Sternberg Astronomical Institute, Lomonosov Moscow State University, Russia > 119991, Moscow, Universitetsky pr-k 13, +7 (495) 9392382 -- With best regards, Matwey V. Kornilov. Sternberg Astronomical Institute, Lomonosov Moscow State University, Russia 119991, Moscow, Universitetsky pr-k 13, +7 (495) 9392382 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html