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

From: Lokesh Vutla
Date: Fri Dec 19 2014 - 00:22:52 EST


Hi Roger,
On Thursday 18 December 2014 09:22 PM, Roger Quadros wrote:
> Fixing up Paul's email id.
>
> cheers,
> -roger
>
> On 18/12/14 17:49, Roger Quadros wrote:
>> There are quite a few hwmods that don't have sysconfig register 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.
>>
>> Get rid of the redundant _find_mpu_rt_port() check from the _wait_target_ready()
>> funcion for all the SoCs. The following PRCM register access that checks the
>> module ready state has nothing to do with module's SYSCONFIG or mpu_rt_port.
Yes, makes sense. This patch looks good to me.
Tested this on AM437x-gp-evm.

Tested-by: Lokesh Vutla <lokeshvutla@xxxxxx>

May be good idea to warn every time if enabling of module is failed?
Unrelated to this patch though.

diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index 4c6b7b2..db67b66 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -2243,7 +2243,7 @@ static int _enable(struct omap_hwmod *oh)
if (soc_ops.disable_module)
soc_ops.disable_module(oh);
_disable_clocks(oh);
- pr_debug("omap_hwmod: %s: _wait_target_ready: %d\n",
+ pr_warn("omap_hwmod: %s: _wait_target_ready failed : %d\n",
oh->name, r);

if (oh->clkdm)


Thanks and regards,
Lokesh

>>
>> 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 ]---
>>
>> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
>> ---
>> arch/arm/mach-omap2/omap_hwmod.c | 12 ------------
>> 1 file changed, 12 deletions(-)
>>
>> diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
>> index 716247e..3afcc65 100644
>> --- a/arch/arm/mach-omap2/omap_hwmod.c
>> +++ b/arch/arm/mach-omap2/omap_hwmod.c
>> @@ -2943,9 +2943,6 @@ static int _omap2xxx_wait_target_ready(struct omap_hwmod *oh)
>> if (oh->flags & HWMOD_NO_IDLEST)
>> return 0;
>>
>> - if (!_find_mpu_rt_port(oh))
>> - return 0;
>> -
>> /* XXX check module SIDLEMODE, hardreset status, enabled clocks */
>>
>> return omap2xxx_cm_wait_module_ready(oh->prcm.omap2.module_offs,
>> @@ -2970,9 +2967,6 @@ static int _omap3xxx_wait_target_ready(struct omap_hwmod *oh)
>> if (oh->flags & HWMOD_NO_IDLEST)
>> return 0;
>>
>> - if (!_find_mpu_rt_port(oh))
>> - return 0;
>> -
>> /* XXX check module SIDLEMODE, hardreset status, enabled clocks */
>>
>> return omap3xxx_cm_wait_module_ready(oh->prcm.omap2.module_offs,
>> @@ -2997,9 +2991,6 @@ static int _omap4_wait_target_ready(struct omap_hwmod *oh)
>> if (oh->flags & HWMOD_NO_IDLEST || !oh->clkdm)
>> return 0;
>>
>> - if (!_find_mpu_rt_port(oh))
>> - return 0;
>> -
>> /* XXX check module SIDLEMODE, hardreset status */
>>
>> return omap4_cminst_wait_module_ready(oh->clkdm->prcm_partition,
>> @@ -3025,9 +3016,6 @@ static int _am33xx_wait_target_ready(struct omap_hwmod *oh)
>> if (oh->flags & HWMOD_NO_IDLEST)
>> return 0;
>>
>> - if (!_find_mpu_rt_port(oh))
>> - return 0;
>> -
>> /* XXX check module SIDLEMODE, hardreset status */
>>
>> return am33xx_cm_wait_module_ready(oh->clkdm->cm_inst,
>>
>
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