On Tue, 2016-08-23 at 08:53 -0500, Dinh Nguyen wrote: > Hi Andy, > > On 08/17/2016 06:14 AM, Andy Shevchenko wrote: > > > > > > I sent a v2 of the series for internal review, same you may found on > > [1]. If Heikki is okay to that I'll send it here. > > > > [1] https://bitbucket.org/andy-shev/linux/branch/topic%2Fdw%2Fqrk > > > > I tested this branch on SoCFPGA hardware and encountered this > error[1]. > Doing a bisect led me to this commit[2]. Thanks! Found today the same. Yes, here is the fix (will push an updated version later): --- a/drivers/tty/serial/8250/8250_dma.c +++ b/drivers/tty/serial/8250/8250_dma.c @@ -260,7 +260,7 @@ void serial8250_release_dma(struct uart_8250_port *p) { struct uart_8250_dma *dma = p->dma; - if (!dma) + if (!dma->in_use) return; /* Release RX resources */ > > Dinh > > > --------------------[1]------------------------------ > > [ 5.907714] ttyS0 - failed to request DMA > [ 5.921937] VFS: Mounted root (nfs filesystem) on device 0:13. > [ 5.928732] devtmpfs: mounted > [ 5.932504] Freeing unused kernel memory: 1024K (c0900000 - > c0a00000) > [ 6.004532] Unable to handle kernel NULL pointer dereference at > virtual address 0000000c > [ 6.012619] pgd = ef670000 > [ 6.015321] [0000000c] *pgd=2ec0a831, *pte=00000000, *ppte=00000000 > [ 6.021609] Internal error: Oops: 17 [#1] SMP ARM > [ 6.026301] Modules linked in: > [ 6.029365] CPU: 1 PID: 1 Comm: init Not tainted > 4.8.0-rc3-00063-g6ce52b1 #12 > [ 6.036476] Hardware name: Altera SOCFPGA > [ 6.040476] task: ef4ac000 task.stack: ef4b0000 > [ 6.045007] PC is at _stop+0x4/0x254 > [ 6.048579] LR is at pl330_terminate_all+0x4c/0x1e4 > [ 6.053447] pc : [<c03c2e5c>] lr : [<c03c30f8>] psr: 60000093 > [ 6.053447] sp : ef4b1e88 ip : 00000000 fp : 0000a109 > [ 6.064890] r10: 00000000 r9 : ef7c7cc0 r8 : eedfaa94 > [ 6.070099] r7 : eed30410 r6 : eec2be0c r5 : 60000013 r4 : > eec2be70 > [ 6.076605] r3 : 00000002 r2 : 00000002 r1 : 00000000 r0 : > 00000000 > [ 6.083113] Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM > Segment none > [ 6.090318] Control: 10c5387d Table: 2f67004a DAC: 00000051 > [ 6.096046] Process init (pid: 1, stack limit = 0xef4b0218) > [ 6.101603] Stack: (0xef4b1e88 to 0xef4b2000) > [ 6.105953] 1e80: eec2be70 60000013 eec2be0c > eedfaa94 ef7c7cc0 c03c30f8 > [ 6.114112] 1ea0: ef4b1ea0 ef4b1ea0 eedfaa00 eed8c02c eec2be20 > 20000013 c0a66208 c03f2b44 > [ 6.122272] 1ec0: 00000001 00000000 c0a66208 c0a66208 c0a66324 > 20000013 c0a66208 eedfaa94 > [ 6.130432] 1ee0: ef7c7cc0 c03f041c eedfaa00 c0a66208 eedfaa8c > c03ea774 eedfaa00 ef7cec00 > [ 6.138592] 1f00: c0a66208 00000001 eedfaa94 c03eb9a4 ef7cec00 > ef1a2930 00000000 ef41bd90 > [ 6.146751] 1f20: ef1a4440 c03d0790 00080040 00080060 00000000 > 00000000 00002710 ef7c7cc0 > [ 6.154911] 1f40: ef1a2930 00000000 ef41bd90 ef1a4440 00000008 > ef7c7cc8 0000a109 c021b594 > [ 6.163071] 1f60: 00000000 00000000 ef4ac3d4 c0a532f8 00000000 > ef4ac000 c0107884 ef4b0000 > [ 6.171231] 1f80: 00000000 c0138a14 ef4b0000 ef4b1fb0 c0107884 > 00000006 c0107884 c010b274 > [ 6.179390] 1fa0: 00015500 00000000 bea16c4c c0107714 00000000 > 00000800 00000045 0000c79c > [ 6.187550] 1fc0: 00015500 00000000 bea16c4c 00000006 bea16bc0 > 00009c59 10000000 0000a109 > [ 6.195709] 1fe0: 00000000 bea16bb4 0000bf81 b6f6413c 40000010 > 00000002 00000c84 01000002 > [ 6.203878] [<c03c2e5c>] (_stop) from [<c03c30f8>] > (pl330_terminate_all+0x4c/0x1e4) > [ 6.211526] [<c03c30f8>] (pl330_terminate_all) from [<c03f2b44>] > (serial8250_release_dma+0x30/0x1c8) > [ 6.220640] [<c03f2b44>] (serial8250_release_dma) from [<c03f041c>] > (serial8250_do_shutdown+0x64/0x144) > [ 6.230019] [<c03f041c>] (serial8250_do_shutdown) from [<c03ea774>] > (uart_shutdown+0xd0/0x104) > [ 6.238614] [<c03ea774>] (uart_shutdown) from [<c03eb9a4>] > (uart_close+0x148/0x298) > [ 6.246266] [<c03eb9a4>] (uart_close) from [<c03d0790>] > (tty_release+0xf0/0x4d4) > [ 6.253658] [<c03d0790>] (tty_release) from [<c021b594>] > (__fput+0x80/0x1c8) > [ 6.260694] [<c021b594>] (__fput) from [<c0138a14>] > (task_work_run+0xb8/0xe8) > [ 6.267822] [<c0138a14>] (task_work_run) from [<c010b274>] > (do_work_pending+0x7c/0xa4) > [ 6.275727] [<c010b274>] (do_work_pending) from [<c0107714>] > (slow_work_pending+0xc/0x20) > [ 6.283888] Code: e8bd8070 e3a04000 eafffff9 e92d4370 (e590300c) > [ 6.289963] ---[ end trace e214cd70660516e6 ]--- > [ 6.294806] Kernel panic - not syncing: Attempted to kill init! > exitcode=0x0000000b > [ 6.294806] > [ 6.303932] CPU0: stopping > [ 6.306645] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G D > 4.8.0-rc3-00063-g6ce52b1 #12 > [ 6.315406] Hardware name: Altera SOCFPGA > [ 6.319425] [<c010fef0>] (unwind_backtrace) from [<c010b8a4>] > (show_stack+0x10/0x14) > [ 6.327159] [<c010b8a4>] (show_stack) from [<c037aa18>] > (dump_stack+0x84/0x98) > [ 6.334372] [<c037aa18>] (dump_stack) from [<c010edb4>] > (handle_IPI+0x2a0/0x2bc) > [ 6.341755] [<c010edb4>] (handle_IPI) from [<c01014cc>] > (gic_handle_irq+0x88/0x8c) > [ 6.349310] [<c01014cc>] (gic_handle_irq) from [<c010c38c>] > (__irq_svc+0x6c/0x90) > [ 6.356775] Exception stack(0xc0a01f50 to 0xc0a01f98) > [ 6.361815] 1f40: 00000000 > ef9cd368 0000153c c01184a0 > [ 6.369976] 1f60: c0a00000 c0a024a4 c0a023c0 c0a50390 c0a02454 > 00000001 c0a02454 00000000 > [ 6.378135] 1f80: 60000013 c0a01fa0 c01081a8 c01081ac 60000013 > ffffffff > [ 6.384734] [<c010c38c>] (__irq_svc) from [<c01081ac>] > (arch_cpu_idle+0x38/0x3c) > [ 6.392127] [<c01081ac>] (arch_cpu_idle) from [<c0158cec>] > (cpu_startup_entry+0x204/0x25c) > [ 6.400379] [<c0158cec>] (cpu_startup_entry) from [<c0900c60>] > (start_kernel+0x370/0x37c) > [ 6.408542] ---[ end Kernel panic - not syncing: Attempted to kill > init! exitcode=0x0000000b > [ 6.408542] > > > --------------------[2]---------------------------------- > commit 60a0605738814ca8fa180cdfef20fcc2a32ec1ef > Author: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > Date: Mon Jun 13 12:17:03 2016 +0300 > > serial: 8250: allow user to skip using of DMA channels > > Currently DMA mode is enforced if the certain driver has such > support. It prevents user to enforce PIO mode for RX, TX, or both. > > The new module parameters skip_rxdma and skip_txdma allow user to > choose between auto mode, which is current and default behaviour, > disable RX, TX, or both DMA channels without hacking a kernel. > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> -- Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Intel Finland Oy -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
