Device tree probed devices don't get dma_mask set. Previously we were setting the dma_mask pointer only if it was NULL. However, the address of 'omap_ehci_dma_mask' would change each time the module is unloaded and loaded back thus causing the devices dma_mask pointer to be invalid on the next load. This will cause page faults if any driver tries to access the old dma_mask pointer. Unconditionally re-setting the dma_mask pointer fixes this problem. e.g. of backtrace when mass storage device is plugged in after ehci-omap module is unloaded and loaded back when booted with device tree. [ 646.398223] Unable to handle kernel paging request at virtual address bf08f678 [ 646.406005] pgd = c0004000 [ 646.408966] [bf08f678] *pgd=8c9ec811, *pte=00000000, *ppte=00000000 [ 646.415649] Internal error: Oops: 7 [#1] SMP ARM [ 646.420532] Modules linked in: ehci_omap ehci_hcd snd_soc_omap snd_soc_omap_mcbsp snd_soc_core regmap_spi snd_compress snd_pcm snd_timer snd soundcore snd_page_alloc [last unloaded: ehci_hcd] [ 646.438629] CPU: 0 PID: 691 Comm: kworker/u2:2 Not tainted 3.10.0-rc2-00047-g519fe2e #490 [ 646.447265] Workqueue: events_unbound async_run_entry_fn [ 646.452880] task: ce12cb80 ti: ce194000 task.ti: ce194000 [ 646.458618] PC is at scsi_calculate_bounce_limit+0x34/0x48 [ 646.464385] LR is at __scsi_alloc_queue+0x80/0x108 [ 646.469451] pc : [<c032a680>] lr : [<c032a714>] psr: a0000013 [ 646.469451] sp : ce195c88 ip : 0000000c fp : 00000001 [ 646.481536] r10: cca4d018 r9 : cca42808 r8 : 00000000 [ 646.487060] r7 : 0000012a r6 : ce527420 r5 : ce3561b0 r4 : ce415000 [ 646.493927] r3 : bf08f678 r2 : ce424cd0 r1 : 000000f0 r0 : ce415000 [ 646.500823] Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel [ 646.508544] Control: 10c5387d Table: 8c9bc019 DAC: 00000015 [ 646.514587] Process kworker/u2:2 (pid: 691, stack limit = 0xce194240) [ 646.521392] Stack: (0xce195c88 to 0xce196000) [ 646.526000] 5c80: ffffffff cca42800 cca4d000 ce415000 ffffffe0 c032b978 [ 646.534606] 5ca0: cca42800 c032c114 ce12cb80 cca4d000 00000000 ce195d64 00000000 ce415000 [ 646.543243] 5cc0: ce194000 00000000 c07b5574 c032c654 00000000 c008c2bc 60000093 ce194000 [ 646.551879] 5ce0: ce12cb80 c04cc890 00000001 ce415000 ce194000 00000000 c07b5574 c008c2bc [ 646.560485] 5d00: 60000013 cca4d0a8 00000004 60000013 ffffffff c04cc890 c07b5880 cca4d000 [ 646.569122] 5d20: 00000000 00000000 ce415180 ffffffff ce194000 00000000 c07b5574 c032cf40 [ 646.577758] 5d40: 00000000 00000000 ce195d8c 00000000 c08a8208 00000000 00000002 00000000 [ 646.586364] 5d60: ce415220 00000000 00000000 00000000 00000002 ce12d010 ce12cb80 00000006 [ 646.595001] 5d80: 00000004 c07b932c 00000006 c008c0fc 00000000 ce12cb80 ce415180 ce194000 [ 646.603637] 5da0: ce12cb80 c04cc890 00000001 ffffffff ce194000 ce415068 c07b5574 c008c2bc [ 646.612243] 5dc0: 60000013 00000001 ce415000 00000000 ffffffff 00000000 ce194000 ce415180 [ 646.620880] 5de0: c07b5574 c032d400 00000000 ce415000 ce415180 ce415000 ffffffff ffffffff [ 646.629516] 5e00: 00000000 ce415180 ce415068 c032d708 cc9759c0 c00690bc 0000005d ce415000 [ 646.638122] 5e20: ce329940 ccae4300 ce195ec0 ccb26dd0 ccb26dc0 c032d824 00000000 00000000 [ 646.646759] 5e40: c07b6f1c ce329940 ccae4300 c032d9c4 00000000 c07b6f1c ce329940 ce03f000 [ 646.655395] 5e60: ce195ec0 c0065384 00000000 00000000 60000013 ce047f00 ce03f000 ccb26dd0 [ 646.664001] 5e80: ce329940 ccb26dd0 ce329940 ce03f000 ce195ec0 00000000 ce047f00 c005842c [ 646.672637] 5ea0: 00000002 00000000 c00583a0 c04ca4d4 ce12cb80 00000002 00000000 00000000 [ 646.681274] 5ec0: c07cb97c c08a8128 00000000 c06187b0 ce03f000 ce329940 ce03f030 ce329958 [ 646.689910] 5ee0: ce194000 ce194000 c07b5208 00000001 ce03f000 c0058b10 00000000 00000000 [ 646.698516] 5f00: 00000000 ce194000 60000113 ce0a1e34 00000000 ce329940 c00589d8 00000000 [ 646.707153] 5f20: 00000000 00000000 00000000 c005ebec ce12cb80 00000000 00000001 ce329940 [ 646.715789] 5f40: 00000000 00000000 dead4ead ffffffff ffffffff c07cb8f4 00000000 00000000 [ 646.724395] 5f60: c0615efc ce195f64 ce195f64 00000000 00000000 dead4ead ffffffff ffffffff [ 646.733032] 5f80: c07cb8f4 00000000 00000000 c0615efc ce195f90 ce195f90 ce195fac ce0a1e34 [ 646.741668] 5fa0: c005eb48 00000000 00000000 c0013688 00000000 00000000 00000000 00000000 [ 646.750274] 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 646.758911] 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000 2a7fef02 00b3ff00 [ 646.767547] [<c032a680>] (scsi_calculate_bounce_limit+0x34/0x48) from [<c032a714>] (__scsi_alloc_queue+0x80/0x108) [ 646.778472] [<c032a714>] (__scsi_alloc_queue+0x80/0x108) from [<c032b978>] (scsi_alloc_queue+0x10/0x60) [ 646.788391] [<c032b978>] (scsi_alloc_queue+0x10/0x60) from [<c032c114>] (scsi_alloc_sdev+0x170/0x270) [ 646.798126] [<c032c114>] (scsi_alloc_sdev+0x170/0x270) from [<c032c654>] (scsi_probe_and_add_lun+0x39c/0x948) [ 646.808593] [<c032c654>] (scsi_probe_and_add_lun+0x39c/0x948) from [<c032cf40>] (__scsi_scan_target+0xd4/0x53c) [ 646.819244] [<c032cf40>] (__scsi_scan_target+0xd4/0x53c) from [<c032d400>] (scsi_scan_channel.part.2+0x58/0x6c) [ 646.829895] [<c032d400>] (scsi_scan_channel.part.2+0x58/0x6c) from [<c032d708>] (scsi_scan_host_selected+0xd0/0x168) [ 646.840972] [<c032d708>] (scsi_scan_host_selected+0xd0/0x168) from [<c032d824>] (do_scsi_scan_host+0x84/0x8c) [ 646.851440] [<c032d824>] (do_scsi_scan_host+0x84/0x8c) from [<c032d9c4>] (do_scan_async+0x10/0x164) [ 646.860992] [<c032d9c4>] (do_scan_async+0x10/0x164) from [<c0065384>] (async_run_entry_fn+0x40/0x180) [ 646.870727] [<c0065384>] (async_run_entry_fn+0x40/0x180) from [<c005842c>] (process_one_work+0x1b4/0x49c) [ 646.880828] [<c005842c>] (process_one_work+0x1b4/0x49c) from [<c0058b10>] (worker_thread+0x138/0x37c) [ 646.890563] [<c0058b10>] (worker_thread+0x138/0x37c) from [<c005ebec>] (kthread+0xa4/0xb0) [ 646.899291] [<c005ebec>] (kthread+0xa4/0xb0) from [<c0013688>] (ret_from_fork+0x14/0x2c) [ 646.907836] Code: e3530000 0a000003 e59331b8 e3530000 (11c320d0) [ 646.914367] ---[ end trace 157a5b85fcd31f7f ]--- Signed-off-by: Roger Quadros <rogerq@xxxxxx> --- drivers/usb/host/ehci-omap.c | 3 +-- 1 files changed, 1 insertions(+), 2 deletions(-) diff --git a/drivers/usb/host/ehci-omap.c b/drivers/usb/host/ehci-omap.c index 3d1491b..b33e306 100644 --- a/drivers/usb/host/ehci-omap.c +++ b/drivers/usb/host/ehci-omap.c @@ -146,8 +146,7 @@ static int ehci_hcd_omap_probe(struct platform_device *pdev) * Since shared usb code relies on it, set it here for now. * Once we have dma capability bindings this can go away. */ - if (!pdev->dev.dma_mask) - pdev->dev.dma_mask = &omap_ehci_dma_mask; + pdev->dev.dma_mask = &omap_ehci_dma_mask; hcd = usb_create_hcd(&ehci_omap_hc_driver, dev, dev_name(dev)); -- 1.7.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html