On Fri, 05 Jul 2013 14:38:55 +0800, Shawn Guo wrote: > Generally request_irq() should be called after hardware has been > initialized into a sane state. However, sdhci driver currently calls > request_irq() before sdhci_init(). At least, the following kernel > panic seen on i.MX6 is caused by that. The sdhci controller on i.MX6 > may have noisy glitch on DAT1 line, which will trigger SDIO interrupt > handling once request_irq() is called. But at this point, the SDIO > interrupt handler host->sdio_irq_thread has not been registered yet. > Thus, we see the NULL pointer access with > wake_up_process(host->sdio_irq_thread) in mmc_signal_sdio_irq(). Thanks for fixing it. I had exactly the same problem with Samsung devices. My fix was to mask the unneeded (for eMMC) SDIO interrupt at the u-boot bootloader (patches to fix this are already at u-boot mainline). But anyway thanks for the kernel fix. > > sdhci-pltfm: SDHCI platform and OF driver helper > mmc0: no vqmmc regulator found > mmc0: no vmmc regulator found > Unable to handle kernel NULL pointer dereference at virtual address > 00000000 pgd = 80004000 > [00000000] *pgd=00000000 > Internal error: Oops: 5 [#1] SMP ARM > Modules linked in: > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.10.0+ #3 > task: 9f860000 ti: 9f862000 task.ti: 9f862000 > PC is at wake_up_process+0xc/0x44 > LR is at sdhci_irq+0x378/0x93c > pc : [<8004f768>] lr : [<803fb698>] psr: 40000193 > sp : 9f863ba0 ip : 9f863bb8 fp : 9f863bb4 > r10: 9f807900 r9 : 80761fbc r8 : 00000000 > r7 : 00000000 r6 : 00000000 r5 : 00000001 r4 : 9fa68000 > r3 : 00000001 r2 : 00000002 r1 : 20000193 r0 : 00000000 > Flags: nZcv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel > Control: 10c53c7d Table: 8000404a DAC: 00000017 > Process swapper/0 (pid: 1, stack limit = 0x9f862238) > Stack: (0x9f863ba0 to 0x9f864000) > 3ba0: 00000001 9fa68000 9f863c04 9f863bb8 803fb698 8004f768 8011af00 > 80265aac 3bc0: 00000000 000003d9 00000000 9fa51880 00000001 00000000 > 9f863c14 9fa53640 3be0: 00000001 00000000 00000000 00000036 80761fbc > 9f807900 9f863c3c 9f863c08 3c00: 80075154 803fb32c 802c2b38 802c63d8 > 802c63cc 9f807900 00000001 9f862000 3c20: 00000036 00000000 9f807930 > 60000113 9f863c54 9f863c40 800752ec 8007510c 3c40: 9f807900 00000001 > 9f863c6c 9f863c58 80078324 800752a8 00000036 8071fd64 3c60: 9f863c84 > 9f863c70 80074ac0 80078294 00000140 8072ab78 9f863cac 9f863c88 3c80: > 8000ee34 80074aa4 00000000 a080e10c 8072acbc 9f863cd0 a080e100 > 00000036 3ca0: 9f863ccc 9f863cb0 80008600 8000edec 805386a8 60000113 > ffffffff 9f863d04 3cc0: 9f863d24 9f863cd0 8000e0c0 800085dc 9f807950 > 60000113 00000007 00000000 3ce0: 9f807900 9fa53640 9f807950 9fa68240 > 00000036 9f807930 60000113 9f863d24 3d00: 9f863d28 9f863d18 80076834 > 805386a8 60000113 ffffffff 9f863d64 9f863d28 3d20: 80076834 80538688 > 00000000 800bfe4c 00002fac 00000001 9f863d54 9fa53640 3d40: 9f807900 > 803fb320 9fa68240 00000080 00000000 00000036 9f863d94 9f863d68 3d60: > 80076b38 80076674 00000080 9fa68240 9fa68000 04000000 9fa6836c > 9fa68380 3d80: 806d620c 80700350 9f863dc4 9f863d98 803fce8c 80076a88 > 9fa532c0 9fa68240 3da0: 9fa51490 9fa51490 9fa68240 00000000 9f8ae600 > 9f81d080 9f863df4 9f863dc8 3dc0: 803fea0c 803fc808 9f863de4 9f863dd8 > 80125850 807b1ed8 807576b8 9f8ae610 3de0: 00000000 807576b8 9f863e04 > 9f863df8 802ee0d4 803fe798 9f863e2c 9f863e08 3e00: 802ecd1c 802ee0c0 > 00000000 9f8ae610 807576b8 9f8ae644 00000000 000000a9 3e20: 9f863e4c > 9f863e30 802ecec0 802ecc30 9f83355c 807576b8 802ece2c 00000000 3e40: > 9f863e74 9f863e50 802eb3d8 802ece38 9f83355c 9f8ac3b4 9f833570 > 807576b8 3e60: 80746e70 9fa51400 9f863e84 9f863e78 802ec838 802eb388 > 9f863eb4 9f863e88 3e80: 802ec3d0 802ec824 80692748 807620c0 9f863eb4 > 807576b8 00000006 807620c0 3ea0: 00000000 000000a9 9f863edc 9f863eb8 > 802ed3e8 802ec2fc 9f862000 00000006 3ec0: 807620c0 00000000 000000a9 > 80700350 9f863eec 9f863ee0 802ee2f8 802ed374 3ee0: 9f863efc 9f863ef0 > 80700364 802ee2b8 9f863f54 9f863f00 8000870c 8070035c 3f00: 9f863f54 > 9f863f10 9f862000 00000000 00000000 00000006 00000006 806d3aa4 3f20: > 00000000 80688b18 9f863f54 80713560 00000006 80713540 807620c0 > 000000a9 3f40: 806d620c 8071ec24 9f863f94 9f863f58 806d6994 800086dc > 00000006 00000006 3f60: 806d620c f6bfffff fb7f5df7 00000000 8052da28 > 00000000 00000000 00000000 3f80: 00000000 00000000 9f863fac 9f863f98 > 8052da38 806d689c ffffffff 00000000 3fa0: 00000000 9f863fb0 8000e5d8 > 8052da34 00000000 00000000 00000000 00000000 3fc0: 00000000 00000000 > 00000000 00000000 00000000 00000000 00000000 00000000 3fe0: 00000000 > 00000000 00000000 00000000 00000013 00000000 d9cdf5ff 1fff5ffe > Backtrace: [<8004f75c>] (wake_up_process+0x0/0x44) from [<803fb698>] > (sdhci_irq+0x378/0x93c) r4:9fa68000 r3:00000001 [<803fb320>] > (sdhci_irq+0x0/0x93c) from [<80075154>] > (handle_irq_event_percpu+0x54/0x19c) [<80075100>] > (handle_irq_event_percpu+0x0/0x19c) from [<800752ec>] > (handle_irq_event+0x50/0x70) [<8007529c>] (handle_irq_event+0x0/0x70) > from [<80078324>] (handle_fasteoi_irq+0x9c/0x170) r5:00000001 > r4:9f807900 [<80078288>] (handle_fasteoi_irq+0x0/0x170) from > [<80074ac0>] (generic_handle_irq+0x28/0x38) r5:8071fd64 r4:00000036 > [<80074a98>] (generic_handle_irq+0x0/0x38) from [<8000ee34>] > (handle_IRQ+0x54/0xb4) r4:8072ab78 r3:00000140 [<8000ede0>] > (handle_IRQ+0x0/0xb4) from [<80008600>] (gic_handle_irq+0x30/0x64) > r8:00000036 r7:a080e100 r6:9f863cd0 r5:8072acbc r4:a080e10c > r3:00000000 [<800085d0>] (gic_handle_irq+0x0/0x64) from [<8000e0c0>] > (__irq_svc+0x40/0x54) Exception stack(0x9f863cd0 to 0x9f863d18) > 3cc0: 9f807950 60000113 00000007 > 00000000 3ce0: 9f807900 9fa53640 9f807950 9fa68240 00000036 9f807930 > 60000113 9f863d24 3d00: 9f863d28 9f863d18 80076834 805386a8 60000113 > ffffffff r7:9f863d04 r6:ffffffff r5:60000113 r4:805386a8 [<8053867c>] > (_raw_spin_unlock_irqrestore+0x0/0x30) from [<80076834>] > (__setup_irq+0x1cc/0x414) [<80076668>] (__setup_irq+0x0/0x414) from > [<80076b38>] (request_threaded_irq+0xbc/0x140) [<80076a7c>] > (request_threaded_irq+0x0/0x140) from [<803fce8c>] > (sdhci_add_host+0x690/0xb88) [<803fc7fc>] (sdhci_add_host+0x0/0xb88) > from [<803fea0c>] (sdhci_esdhc_imx_probe+0x280/0x4d4) r8:9f81d080 > r7:9f8ae600 r6:00000000 r5:9fa68240 r4:9fa51490 [<803fe78c>] > (sdhci_esdhc_imx_probe+0x0/0x4d4) from [<802ee0d4>] > (platform_drv_probe+0x20/0x24) r8:807576b8 r7:00000000 r6:9f8ae610 > r5:807576b8 r4:807b1ed8 [<802ee0b4>] (platform_drv_probe+0x0/0x24) > from [<802ecd1c>] (driver_probe_device+0xf8/0x208) [<802ecc24>] > (driver_probe_device+0x0/0x208) from [<802ecec0>] > (__driver_attach+0x94/0x98) r8:000000a9 r7:00000000 r6:9f8ae644 > r5:807576b8 r4:9f8ae610 r3:00000000 [<802ece2c>] > (__driver_attach+0x0/0x98) from [<802eb3d8>] > (bus_for_each_dev+0x5c/0x90) r6:00000000 r5:802ece2c r4:807576b8 > r3:9f83355c [<802eb37c>] (bus_for_each_dev+0x0/0x90) from > [<802ec838>] (driver_attach+0x20/0x28) r6:9fa51400 r5:80746e70 > r4:807576b8 [<802ec818>] (driver_attach+0x0/0x28) from [<802ec3d0>] > (bus_add_driver+0xe0/0x234) [<802ec2f0>] (bus_add_driver+0x0/0x234) > from [<802ed3e8>] (driver_register+0x80/0x14c) r8:000000a9 > r7:00000000 r6:807620c0 r5:00000006 r4:807576b8 [<802ed368>] > (driver_register+0x0/0x14c) from [<802ee2f8>] > (platform_driver_register+0x4c/0x60) [<802ee2ac>] > (platform_driver_register+0x0/0x60) from [<80700364>] > (sdhci_esdhc_imx_driver_init+0x14/0x1c) [<80700350>] > (sdhci_esdhc_imx_driver_init+0x0/0x1c) from [<8000870c>] > (do_one_initcall+0x3c/0x164) [<800086d0>] (do_one_initcall+0x0/0x164) > from [<806d6994>] (kernel_init_freeable+0x104/0x1d0) [<806d6890>] > (kernel_init_freeable+0x0/0x1d0) from [<8052da38>] > (kernel_init+0x10/0xec) [<8052da28>] (kernel_init+0x0/0xec) from > [<8000e5d8>] (ret_from_fork+0x14/0x3c) r4:00000000 r3:ffffffff Code: > e89da800 e1a0c00d e92dd818 e24cb004 (e5903000) ---[ end trace > e9af3588936b63f0 ]--- Kernel panic - not syncing: Fatal exception in > interrupt > > Fix the panic by simply reverse the calling sequence between > request_irq() and sdhci_init(). > > Signed-off-by: Shawn Guo <shawn.guo@xxxxxxxxxx> > --- > drivers/mmc/host/sdhci.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c > index 2ea429c..a821b71 100644 > --- a/drivers/mmc/host/sdhci.c > +++ b/drivers/mmc/host/sdhci.c > @@ -3174,6 +3174,8 @@ int sdhci_add_host(struct sdhci_host *host) > host->tuning_timer.function = sdhci_tuning_timer; > } > > + sdhci_init(host, 0); > + > ret = request_irq(host->irq, sdhci_irq, IRQF_SHARED, > mmc_hostname(mmc), host); > if (ret) { > @@ -3182,8 +3184,6 @@ int sdhci_add_host(struct sdhci_host *host) > goto untasklet; > } > > - sdhci_init(host, 0); > - > #ifdef CONFIG_MMC_DEBUG > sdhci_dumpregs(host); > #endif -- Best regards, Lukasz Majewski Samsung R&D Institute Poland (SRPOL) | Linux Platform Group -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html