[PATCH v3] ARM: OMAP2+: hwmod: Fix _wait_target_ready() for hwmods without sysc

Tue Jul 28 06:22:15 PDT 2015

On 28/07/15 16:15, Paul Walmsley wrote:
> On Mon, 27 Jul 2015, Roger Quadros wrote:
> 
>> Hi,
>>
>> On 16/07/15 16:16, Roger Quadros wrote:
>>> For hwmods without sysc, _init_mpu_rt_base(oh) won't be called and so
>>> _find_mpu_rt_port(oh) will return NULL thus preventing ready state check
>>> on those modules after the module is enabled.
>>>
>>> This can potentially cause a bus access error if the module is accessed
>>> before the module is ready.
>>>
>>> Fix this by unconditionally calling _init_mpu_rt_base() during hwmod
>>> _init(). Do ioremap only if we need SYSC access.
>>>
>>> Eventhough _wait_target_ready() check doesn't really need MPU RT port but
>>> just the PRCM registers, we still mandate that the hwmod must have an
>>> MPU RT port if ready state check needs to be done. Else it would mean that
>>> the module is not accessible by MPU so there is no point in waiting
>>> for target to be ready.
>>>
>>> e.g. this fixes the below DCAN bus access error on AM437x-gp-evm.
>>>
>>> [   16.672978] ------------[ cut here ]------------
>>> [   16.677885] WARNING: CPU: 0 PID: 1580 at drivers/bus/omap_l3_noc.c:147 l3_interrupt_handler+0x234/0x35c()
>>> [   16.687946] 44000000.ocp:L3 Custom Error: MASTER M2 (64-bit) TARGET L4_PER_0 (Read): Data Access in User mode during Functional access
>>> [   16.700654] Modules linked in: xhci_hcd btwilink ti_vpfe dwc3 videobuf2_core ov2659 bluetooth v4l2_common videodev ti_am335x_adc kfifo_buf industrialio c_can_platform videobuf2_dma_contig media snd_soc_tlv320aic3x pixcir_i2c_ts c_can dc
>>> [   16.731144] CPU: 0 PID: 1580 Comm: rpc.statd Not tainted 3.14.26-02561-gf733aa036398 #180
>>> [   16.739747] Backtrace:
>>> [   16.742336] [<c0011108>] (dump_backtrace) from [<c00112a4>] (show_stack+0x18/0x1c)
>>> [   16.750285]  r6:00000093 r5:00000009 r4:eab5b8a8 r3:00000000
>>> [   16.756252] [<c001128c>] (show_stack) from [<c05a4418>] (dump_stack+0x20/0x28)
>>> [   16.763870] [<c05a43f8>] (dump_stack) from [<c0037120>] (warn_slowpath_common+0x6c/0x8c)
>>> [   16.772408] [<c00370b4>] (warn_slowpath_common) from [<c00371e4>] (warn_slowpath_fmt+0x38/0x40)
>>> [   16.781550]  r8:c05d1f90 r7:c0730844 r6:c0730448 r5:80080003 r4:ed0cd210
>>> [   16.788626] [<c00371b0>] (warn_slowpath_fmt) from [<c027fa94>] (l3_interrupt_handler+0x234/0x35c)
>>> [   16.797968]  r3:ed0cd480 r2:c0730508
>>> [   16.801747] [<c027f860>] (l3_interrupt_handler) from [<c0063758>] (handle_irq_event_percpu+0x54/0x1bc)
>>> [   16.811533]  r10:ed005600 r9:c084855b r8:0000002a r7:00000000 r6:00000000 r5:0000002a
>>> [   16.819780]  r4:ed0e6d80
>>> [   16.822453] [<c0063704>] (handle_irq_event_percpu) from [<c00638f0>] (handle_irq_event+0x30/0x40)
>>> [   16.831789]  r10:eb2b6938 r9:eb2b6960 r8:bf011420 r7:fa240100 r6:00000000 r5:0000002a
>>> [   16.840052]  r4:ed005600
>>> [   16.842744] [<c00638c0>] (handle_irq_event) from [<c00661d8>] (handle_fasteoi_irq+0x74/0x128)
>>> [   16.851702]  r4:ed005600 r3:00000000
>>> [   16.855479] [<c0066164>] (handle_fasteoi_irq) from [<c0063068>] (generic_handle_irq+0x28/0x38)
>>> [   16.864523]  r4:0000002a r3:c0066164
>>> [   16.868294] [<c0063040>] (generic_handle_irq) from [<c000ef60>] (handle_IRQ+0x38/0x8c)
>>> [   16.876612]  r4:c081c640 r3:00000202
>>> [   16.880380] [<c000ef28>] (handle_IRQ) from [<c00084f0>] (gic_handle_irq+0x30/0x5c)
>>> [   16.888328]  r6:eab5ba38 r5:c0804460 r4:fa24010c r3:00000100
>>> [   16.894303] [<c00084c0>] (gic_handle_irq) from [<c05a8d80>] (__irq_svc+0x40/0x50)
>>> [   16.902193] Exception stack(0xeab5ba38 to 0xeab5ba80)
>>> [   16.907499] ba20:                                                       00000000 00000006
>>> [   16.916108] ba40: fa1d0000 fa1d0008 ed3d3000 eab5bab4 ed3d3460 c0842af4 bf011420 eb2b6960
>>> [   16.924716] ba60: eb2b6938 eab5ba8c eab5ba90 eab5ba80 bf035220 bf07702c 600f0013 ffffffff
>>> [   16.933317]  r7:eab5ba6c r6:ffffffff r5:600f0013 r4:bf07702c
>>> [   16.939317] [<bf077000>] (c_can_plat_read_reg_aligned_to_16bit [c_can_platform]) from [<bf035220>] (c_can_get_berr_counter+0x38/0x64 [c_can])
>>> [   16.952696] [<bf0351e8>] (c_can_get_berr_counter [c_can]) from [<bf010294>] (can_fill_info+0x124/0x15c [can_dev])
>>> [   16.963480]  r5:ec8c9740 r4:ed3d3000
>>> [   16.967253] [<bf010170>] (can_fill_info [can_dev]) from [<c0502fa8>] (rtnl_fill_ifinfo+0x58c/0x8fc)
>>> [   16.976749]  r6:ec8c9740 r5:ed3d3000 r4:eb2b6780
>>> [   16.981613] [<c0502a1c>] (rtnl_fill_ifinfo) from [<c0503408>] (rtnl_dump_ifinfo+0xf0/0x1dc)
>>> [   16.990401]  r10:ec8c9740 r9:00000000 r8:00000000 r7:00000000 r6:ebd4d1b4 r5:ed3d3000
>>> [   16.998671]  r4:00000000
>>> [   17.001342] [<c0503318>] (rtnl_dump_ifinfo) from [<c050e6e4>] (netlink_dump+0xa8/0x1e0)
>>> [   17.009772]  r10:00000000 r9:00000000 r8:c0503318 r7:ebf3e6c0 r6:ebd4d1b4 r5:ec8c9740
>>> [   17.018050]  r4:ebd4d000
>>> [   17.020714] [<c050e63c>] (netlink_dump) from [<c050ec10>] (__netlink_dump_start+0x104/0x154)
>>> [   17.029591]  r6:eab5bd34 r5:ec8c9980 r4:ebd4d000
>>> [   17.034454] [<c050eb0c>] (__netlink_dump_start) from [<c0505604>] (rtnetlink_rcv_msg+0x110/0x1f4)
>>> [   17.043778]  r7:00000000 r6:ec8c9980 r5:00000f40 r4:ebf3e6c0
>>> [   17.049743] [<c05054f4>] (rtnetlink_rcv_msg) from [<c05108e8>] (netlink_rcv_skb+0xb4/0xc8)
>>> [   17.058449]  r8:eab5bdac r7:ec8c9980 r6:c05054f4 r5:ec8c9980 r4:ebf3e6c0
>>> [   17.065534] [<c0510834>] (netlink_rcv_skb) from [<c0504134>] (rtnetlink_rcv+0x24/0x2c)
>>> [   17.073854]  r6:ebd4d000 r5:00000014 r4:ec8c9980 r3:c0504110
>>> [   17.079846] [<c0504110>] (rtnetlink_rcv) from [<c05102ac>] (netlink_unicast+0x180/0x1ec)
>>> [   17.088363]  r4:ed0c6800 r3:c0504110
>>> [   17.092113] [<c051012c>] (netlink_unicast) from [<c0510670>] (netlink_sendmsg+0x2ac/0x380)
>>> [   17.100813]  r10:00000000 r8:00000008 r7:ec8c9980 r6:ebd4d000 r5:eab5be70 r4:eab5bee4
>>> [   17.109083] [<c05103c4>] (netlink_sendmsg) from [<c04dfdb4>] (sock_sendmsg+0x90/0xb0)
>>> [   17.117305]  r10:00000000 r9:eab5a000 r8:becdda3c r7:0000000c r6:ea978400 r5:eab5be70
>>> [   17.125563]  r4:c05103c4
>>> [   17.128225] [<c04dfd24>] (sock_sendmsg) from [<c04e1c28>] (SyS_sendto+0xb8/0xdc)
>>> [   17.136001]  r6:becdda5c r5:00000014 r4:ecd37040
>>> [   17.140876] [<c04e1b70>] (SyS_sendto) from [<c000e680>] (ret_fast_syscall+0x0/0x30)
>>> [   17.148923]  r10:00000000 r8:c000e804 r7:00000122 r6:becdda5c r5:0000000c r4:becdda5c
>>> [   17.157169] ---[ end trace 2b71e15b38f58bad ]---
>>>
>>> Fixes: 6423d6df1440 ("ARM: OMAP2+: hwmod: check for module address space during init")
>>> Signed-off-by: Roger Quadros <rogerq at ti.com>
>>> ---
>>>  arch/arm/mach-omap2/omap_hwmod.c | 24 ++++++++++++++++--------
>>>  1 file changed, 16 insertions(+), 8 deletions(-)
>>
>> Any comments on this one?
> 
> It's been merged by the arm-soc folks as part of a v4.2-rc OMAP 
> fixes series: 
> 
> http://www.spinics.net/lists/arm-kernel/msg434363.html

Great! Thanks.

cheers,
-roger