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authorGrygorii Strashko <grygorii.strashko@ti.com>2015-09-01 13:59:24 -0700
committerTony Lindgren <tony@atomide.com>2015-09-01 13:59:24 -0700
commitfe8291e82b5d0b79b743683e5c0fb7e273f7a99a (patch)
treef634e17887f26d2e155448970153a8cd9df69c00 /arch/arm/mach-omap2/omap_device.c
parent2faf962d90ca4c5ee7ba026b7351b1f74500bcdf (diff)
downloadlinux-linaro-stable-fe8291e82b5d0b79b743683e5c0fb7e273f7a99a.tar.gz
ARM: OMAP2+: omap-device: fix race deferred probe of omap_hsmmc vs omap_device_late_init
Kernel fails to boot 50% of times (form build to build) with RT-patchset applied due to the following race - on late boot stages deferred_probe_work_func->omap_hsmmc_probe races with omap_device_late_ini. The same issue has been reported now on linux-next (4.3) by Keerthy [1] late_initcall - deferred_probe_initcal() tries to re-probe all pending driver's probe. - later on, some driver is probing in this case It's cpsw.c (but could be any other drivers) cpsw_init - platform_driver_register - really_probe - driver_bound - driver_deferred_probe_trigger and boot proceed. So, at this moment we have deferred_probe_work_func scheduled. late_initcall_sync - omap_device_late_init - omap_device_idle CPU1 CPU2 - deferred_probe_work_func - really_probe - omap_hsmmc_probe - pm_runtime_get_sync late_initcall_sync - omap_device_late_init if (od->_driver_status != BUS_NOTIFY_BOUND_DRIVER) { if (od->_state == OMAP_DEVICE_STATE_ENABLED) { - omap_device_idle [ops - IP is disabled] - [fail] - pm_runtime_put_sync - omap_hsmmc_runtime_suspend [ooops!] == log == omap_hsmmc 480b4000.mmc: unable to get vmmc regulator -517 davinci_mdio 48485000.mdio: davinci mdio revision 1.6 davinci_mdio 48485000.mdio: detected phy mask fffffff3 libphy: 48485000.mdio: probed davinci_mdio 48485000.mdio: phy[2]: device 48485000.mdio:02, driver unknown davinci_mdio 48485000.mdio: phy[3]: device 48485000.mdio:03, driver unknown omap_hsmmc 480b4000.mmc: unable to get vmmc regulator -517 cpsw 48484000.ethernet: Detected MACID = b4:99:4c:c7:d2:48 cpsw 48484000.ethernet: cpsw: Detected MACID = b4:99:4c:c7:d2:49 hctosys: unable to open rtc device (rtc0) omap_hsmmc 480b4000.mmc: omap_device_late_idle: enabled but no driver. Idling ldousb: disabling Unhandled fault: imprecise external abort (0x1406) at 0x00000000 [00000000] *pgd=00000000 Internal error: : 1406 [#1] PREEMPT SMP ARM Modules linked in: CPU: 1 PID: 58 Comm: kworker/u4:1 Not tainted 4.1.2-rt1-00467-g6da3c0a-dirty #5 Hardware name: Generic DRA74X (Flattened Device Tree) Workqueue: deferwq deferred_probe_work_func task: ee6ddb00 ti: edd3c000 task.ti: edd3c000 PC is at omap_hsmmc_runtime_suspend+0x1c/0x12c LR is at _od_runtime_suspend+0xc/0x24 pc : [<c0471998>] lr : [<c0029590>] psr: a0000013 sp : edd3dda0 ip : ee6ddb00 fp : c07be540 r10: 00000000 r9 : c07be540 r8 : 00000008 r7 : 00000000 r6 : ee646c10 r5 : ee646c10 r4 : edd79380 r3 : fa0b4100 r2 : 00000000 r1 : 00000000 r0 : ee646c10 Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c5387d Table: 8000406a DAC: 00000015 Process kworker/u4:1 (pid: 58, stack limit = 0xedd3c218) Stack: (0xedd3dda0 to 0xedd3e000) dda0: ee646c70 ee646c10 c0029584 00000000 00000008 c0029590 ee646c70 ee646c10 ddc0: c0029584 c03adfb8 ee646c10 00000004 0000000c c03adff0 ee646c10 00000004 dde0: 0000000c c03ae4ec 00000000 edd3c000 ee646c10 00000004 ee646c70 00000004 de00: fa0b4000 c03aec20 ee6ddb00 ee646c10 00000004 ee646c70 ee646c10 fffffdfb de20: edd79380 00000000 fa0b4000 c03aee90 fffffdfb edd79000 ee646c00 c0474290 de40: 00000000 edda24c0 edd79380 edc81f00 00000000 00000200 00000001 c06dd488 de60: edda3960 ee646c10 ee646c10 c0824cc4 fffffdfb c0880c94 00000002 edc92600 de80: c0836378 c03a7f84 ee646c10 c0824cc4 00000000 c0880c80 c0880c94 c03a6568 dea0: 00000000 ee646c10 c03a66ac ee4f8000 00000000 00000001 edc92600 c03a4b40 dec0: ee404c94 edc83c4c ee646c10 ee646c10 ee646c44 c03a63c4 ee646c10 ee646c10 dee0: c0814448 c03a5aa8 ee646c10 c0814220 edd3c000 c03a5ec0 c0814250 ee6be400 df00: edd3c000 c004e5bc ee6ddb01 00000078 ee6ddb00 ee4f8000 ee6be418 edd3c000 df20: ee4f8028 00000088 c0836045 ee4f8000 ee6be400 c004e928 ee4f8028 00000000 df40: c004e8ec 00000000 ee6bf1c0 ee6be400 c004e8ec 00000000 00000000 00000000 df60: 00000000 c0053450 2e56fa97 00000000 afdffbd7 ee6be400 00000000 00000000 df80: edd3df80 edd3df80 00000000 00000000 edd3df90 edd3df90 edd3dfac ee6bf1c0 dfa0: c0053384 00000000 00000000 c000f668 00000000 00000000 00000000 00000000 dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 dfe0: 00000000 00000000 00000000 00000000 00000013 00000000 f1fc9d7e febfbdff [<c0471998>] (omap_hsmmc_runtime_suspend) from [<c0029590>] (_od_runtime_suspend+0xc/0x24) [<c0029590>] (_od_runtime_suspend) from [<c03adfb8>] (__rpm_callback+0x24/0x3c) [<c03adfb8>] (__rpm_callback) from [<c03adff0>] (rpm_callback+0x20/0x80) [<c03adff0>] (rpm_callback) from [<c03ae4ec>] (rpm_suspend+0xe4/0x618) [<c03ae4ec>] (rpm_suspend) from [<c03aee90>] (__pm_runtime_idle+0x60/0x80) [<c03aee90>] (__pm_runtime_idle) from [<c0474290>] (omap_hsmmc_probe+0x6bc/0xa7c) [<c0474290>] (omap_hsmmc_probe) from [<c03a7f84>] (platform_drv_probe+0x44/0xa4) [<c03a7f84>] (platform_drv_probe) from [<c03a6568>] (driver_probe_device+0x170/0x2b4) [<c03a6568>] (driver_probe_device) from [<c03a4b40>] (bus_for_each_drv+0x64/0x98) [<c03a4b40>] (bus_for_each_drv) from [<c03a63c4>] (device_attach+0x70/0x88) [<c03a63c4>] (device_attach) from [<c03a5aa8>] (bus_probe_device+0x84/0xac) [<c03a5aa8>] (bus_probe_device) from [<c03a5ec0>] (deferred_probe_work_func+0x58/0x88) [<c03a5ec0>] (deferred_probe_work_func) from [<c004e5bc>] (process_one_work+0x134/0x464) [<c004e5bc>] (process_one_work) from [<c004e928>] (worker_thread+0x3c/0x4fc) [<c004e928>] (worker_thread) from [<c0053450>] (kthread+0xcc/0xe4) [<c0053450>] (kthread) from [<c000f668>] (ret_from_fork+0x14/0x2c) Code: e594302c e593202c e584205c e594302c (e5932128) ---[ end trace 0000000000000002 ]--- The issue happens because omap_device_late_init() do not take into account that some drivers are present, but their probes were not finished successfully and where deferred instead. This is the valid case, and omap_device_late_init() should not idle such devices. To fix this issue, the value of omap_device->_driver_status field should be checked not only for BUS_NOTIFY_BOUND_DRIVER (driver is present and has been bound to device successfully), but also checked for BUS_NOTIFY_BIND_DRIVER (driver about to be bound) - which means driver is present and there was try to bind it to device. [1] http://www.spinics.net/lists/arm-kernel/msg441880.html Cc: Tero Kristo <t-kristo@ti.com> Cc: Keerthy <j-keerthy@ti.com> Tested-by: Keerthy <j-keerthy@ti.com> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
Diffstat (limited to 'arch/arm/mach-omap2/omap_device.c')
-rw-r--r--arch/arm/mach-omap2/omap_device.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm/mach-omap2/omap_device.c b/arch/arm/mach-omap2/omap_device.c
index 4cb8fd9f741f..72ebc4c16bae 100644
--- a/arch/arm/mach-omap2/omap_device.c
+++ b/arch/arm/mach-omap2/omap_device.c
@@ -901,7 +901,8 @@ static int __init omap_device_late_idle(struct device *dev, void *data)
if (od->hwmods[i]->flags & HWMOD_INIT_NO_IDLE)
return 0;
- if (od->_driver_status != BUS_NOTIFY_BOUND_DRIVER) {
+ if (od->_driver_status != BUS_NOTIFY_BOUND_DRIVER &&
+ od->_driver_status != BUS_NOTIFY_BIND_DRIVER) {
if (od->_state == OMAP_DEVICE_STATE_ENABLED) {
dev_warn(dev, "%s: enabled but no driver. Idling\n",
__func__);