gpmc_cs_request() causes early boot hang

gpmc_cs_request() causes early boot hang

[Mark Jackson]

I'm developing a beaglebone cape board which requires the use of a GPMC 
chip select.

I've chosen GPMC_CS0, and in board-am335xevm.c, I have added the following:-

static void gpmc_test()
{
     unsigned long base = 0x12345678;
     gpmc_cs_request(0, SZ_16M, &base);
     printk(KERN_INFO "gpmc base @ 0x%08lx\n", base);
}

... and added a call to gpmc_test() at the end of am335x_evm_init().

If I try to run this code, the kernel fails to boot, and simply hangs at:-

Uncompressing Linux... done, booting the kernel.

If I comment out the call to gpmc_cs_request(), the system boots as 
expected (but without my required cs).

I've looked at the use of this call in other board files, and can't see 
that their code does anything special so I'm stuck on why this simple 
code fails to work.

Can anyone shed light on what I'm doing wrong ?

Do I have to initialise the gpmc beforehand in some way ?

Cheers
Mark JACKSON

Re: gpmc_cs_request() causes early boot hang

[Tony Lindgren]

* Mark Jackson <mpfj-list@mimc.co.uk> [120921 12:29]:
> I'm developing a beaglebone cape board which requires the use of a
> GPMC chip select.
> 
> I've chosen GPMC_CS0, and in board-am335xevm.c, I have added the following:-
> 
> static void gpmc_test()
> {
>     unsigned long base = 0x12345678;
>     gpmc_cs_request(0, SZ_16M, &base);
>     printk(KERN_INFO "gpmc base @ 0x%08lx\n", base);
> }
> 
> ... and added a call to gpmc_test() at the end of am335x_evm_init().
> 
> If I try to run this code, the kernel fails to boot, and simply hangs at:-
> 
> Uncompressing Linux... done, booting the kernel.
> 
> If I comment out the call to gpmc_cs_request(), the system boots as
> expected (but without my required cs).
> 
> I've looked at the use of this call in other board files, and can't
> see that their code does anything special so I'm stuck on why this
> simple code fails to work.
> 
> Can anyone shed light on what I'm doing wrong ?
> 
> Do I have to initialise the gpmc beforehand in some way ?

Can you enable DEBUG_LL + EARLYPRINTK and have earlyprintk in your
cmdline? You may then get some error messages providing more info.

GPMC is working on many boards with various devices like smsc911x,
onenand, tusb etc.

Regards,

Tony

RE: gpmc_cs_request() causes early boot hang

[Mohammed, Afzal]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 1292 bytes --]

Hi Mark,

On Sat, Sep 22, 2012 at 00:57:38, Mark Jackson wrote:
> I'm developing a beaglebone cape board which requires the use of a GPMC 
> chip select.
> 
> I've chosen GPMC_CS0, and in board-am335xevm.c, I have added the following:-
> 
> static void gpmc_test()
> {
>      unsigned long base = 0x12345678;
>      gpmc_cs_request(0, SZ_16M, &base);
>      printk(KERN_INFO "gpmc base @ 0x%08lx\n", base);
> }
> 
> ... and added a call to gpmc_test() at the end of am335x_evm_init().
> 
> If I try to run this code, the kernel fails to boot, and simply hangs at:-
> 
> Uncompressing Linux... done, booting the kernel.
> 
> If I comment out the call to gpmc_cs_request(), the system boots as 
> expected (but without my required cs).
> 
> I've looked at the use of this call in other board files, and can't see 
> that their code does anything special so I'm stuck on why this simple 
> code fails to work.
> 
> Can anyone shed light on what I'm doing wrong ?
> 
> Do I have to initialise the gpmc beforehand in some way ?

It seems you are using PSP Kernel.

Invoking omap_init_gpmc before gpmc request should help.

Regards
Afzal
ÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a­¢f£¢·hšïêÿ‘êçz_è®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨è­Ú&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥

Re: gpmc_cs_request() causes early boot hang

[Mark Jackson]

On 24/09/12 05:51, Mohammed, Afzal wrote:
> 
> It seems you are using PSP Kernel.
> 
> Invoking omap_init_gpmc before gpmc request should help.

Okay ... I'm now using earlyprintk and omap_init_gpmc(), but I still get boot hangs.

My test code is as follows:-

diff --git a/arch/arm/mach-omap2/board-am335xevm.c b/arch/arm/mach-omap2/board-am335xevm.c
index dc62ba2..be47e4f 100644
--- a/arch/arm/mach-omap2/board-am335xevm.c
+++ b/arch/arm/mach-omap2/board-am335xevm.c
@@ -4295,6 +4295,20 @@ static void __init am33xx_cpuidle_init(void)

 }

+static void gpmc_test(void)
+{
+       unsigned long base = 0x12345678;
+
+       struct gpmc_devices_info gpmc_device[2] = {
+                       { NULL, GPMC_DEVICE_NOR },
+               };
+
+       setup_pin_mux(gpmc_pin_mux);
+       omap_init_gpmc(gpmc_device, sizeof(gpmc_device));
+       gpmc_cs_request(0, SZ_16M, &base);
+       printk(KERN_INFO "gpmc base @ 0x%08lx\n", base);
+}
+
 static void __init am335x_evm_init(void)
 {
        am33xx_cpuidle_init();
@@ -4313,6 +4327,8 @@ static void __init am335x_evm_init(void)
        /* Create an alias for gfx/sgx clock */
        if (clk_add_alias("sgx_ck", NULL, "gfx_fclk", NULL))
                pr_warn("failed to create an alias: gfx_fclk --> sgx_ck\n");
+
+       gpmc_test();
 }

 static void __init am335x_evm_map_io(void)

----

But this then fails with the following boot log:-

Uncompressing Linux... done, booting the kernel.
[    0.000000] Initializing cgroup subsys cpu
[    0.000000] Linux version 3.2.28+ (mpfj@mpfj-nanobone) (gcc version 4.5.4 (Buildroot
2012.08-git-00388-g7019407) ) #127 Mon Sep 24 11:27:18 BST 2012
[    0.000000] CPU: ARMv7 Processor [413fc082] revision 2 (ARMv7), cr=50c53c7d
[    0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
[    0.000000] Machine: am335xevm
[    0.000000] bootconsole [earlycon0] enabled
[    0.000000] Memory policy: ECC disabled, Data cache writeback
[    0.000000] On node 0 totalpages: 65536
[    0.000000] free_area_init_node: node 0, pgdat c044ca14, node_mem_map c04b1000
[    0.000000]   Normal zone: 512 pages used for memmap
[    0.000000]   Normal zone: 0 pages reserved
[    0.000000]   Normal zone: 65024 pages, LIFO batch:15
[    0.000000] AM335X ES1.0 (sgx neon )
[    0.000000] pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768
[    0.000000] pcpu-alloc: [0] 0
[    0.000000] Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 65024
[    0.000000] Kernel command line: console=ttyO0,115200n8 earlyprintk debug root=/dev/mmcblk0p2 ro
rootfstype=ext2 rootwait ip=none
[    0.000000] PID hash table entries: 1024 (order: 0, 4096 bytes)
[    0.000000] Dentry cache hash table entries: 32768 (order: 5, 131072 bytes)
[    0.000000] Inode-cache hash table entries: 16384 (order: 4, 65536 bytes)
[    0.000000] Memory: 256MB = 256MB total
[    0.000000] Memory: 255052k/255052k available, 7092k reserved, 0K highmem
[    0.000000] Virtual kernel memory layout:
[    0.000000]     vector  : 0xffff0000 - 0xffff1000   (   4 kB)
[    0.000000]     fixmap  : 0xfff00000 - 0xfffe0000   ( 896 kB)
[    0.000000]     vmalloc : 0xd0800000 - 0xff000000   ( 744 MB)
[    0.000000]     lowmem  : 0xc0000000 - 0xd0000000   ( 256 MB)
[    0.000000]     modules : 0xbf800000 - 0xc0000000   (   8 MB)
[    0.000000]       .text : 0xc0008000 - 0xc03de0ec   (3929 kB)
[    0.000000]       .init : 0xc03df000 - 0xc0404000   ( 148 kB)
[    0.000000]       .data : 0xc0404000 - 0xc044dd58   ( 296 kB)
[    0.000000]        .bss : 0xc044dd7c - 0xc04b0694   ( 395 kB)
[    0.000000] NR_IRQS:396 nr_irqs:396 396
[    0.000000] IRQ: Found an INTC at 0xfa200000 (revision 5.0) with 128 interrupts
[    0.000000] Total of 128 interrupts on 1 active controller
[    0.000000] OMAP clockevent source: GPTIMER2 at 24000000 Hz
[    0.000000] OMAP clocksource: GPTIMER1 at 32768 Hz
[    0.000000] sched_clock: 32 bits at 32kHz, resolution 30517ns, wraps every 131071999ms
[    0.000000] Console: colour dummy device 80x30
[    0.004943] Calibrating delay loop... 498.89 BogoMIPS (lpj=2494464)
[    0.062072] pid_max: default: 32768 minimum: 301
[    0.067047] Security Framework initialized
[    0.071441] Mount-cache hash table entries: 512
[    0.076599] Initializing cgroup subsys cpuacct
[    0.081329] Initializing cgroup subsys devices
[    0.085998] Initializing cgroup subsys freezer
[    0.090728] CPU: Testing write buffer coherency: ok
[    0.097045] devtmpfs: initialized
[    0.102478] ttyO0 used as console in debug mode uart0 clocks will not be gated
[    0.128417] omap_hwmod: gfx: failed to hardreset
[    0.150238] omap_hwmod: pruss: failed to hardreset
[    0.155822] print_constraints: dummy:
[    0.160064] NET: Registered protocol family 16
[    0.165985] OMAP GPIO hardware version 0.1
[    0.171600] omap_mux_init: Add partition: #1: core, flags: 0
[    0.179107]  omap_i2c.1: alias fck already exists
[    0.185028] Unable to handle kernel NULL pointer dereference at virtual address 00000010
[    0.193481] pgd = c0004000
[    0.196350] [00000010] *pgd=00000000
[    0.200134] Internal error: Oops: 5 [#1]
[    0.204254] Modules linked in:
[    0.207489] CPU: 0    Not tainted  (3.2.28+ #127)
[    0.212463] PC is at gpmc_cs_reserved+0x14/0x20
[    0.217224] LR is at gpmc_cs_request+0x35/0xd0
[    0.221862] pc : [<c0015ff4>]    lr : [<c0016085>]    psr: 00000033
[    0.221893] sp : cf837f58  ip : 00000000  fp : 00000000
[    0.233886] r10: 00000000  r9 : 00000000  r8 : 00000000
[    0.239349] r7 : 00000000  r6 : 01000000  r5 : fffffff0  r4 : 00000000
[    0.246154] r3 : 00000000  r2 : cf837fa4  r1 : 01000000  r0 : 00000001
[    0.252990] Flags: nzcv  IRQs on  FIQs on  Mode SVC_32  ISA Thumb  Segment kernel
[    0.260772] Control: 50c5387d  Table: 80004019  DAC: 00000015
[    0.266784] Process swapper (pid: 1, stack limit = 0xcf8362f0)
[    0.272888] Stack: (0xcf837f58 to 0xcf838000)
[    0.277465] 7f40:                                                       00000000 00000010
[    0.285980] 7f60: cf837f94 c041e194 cf85dac0 c03e491b 00000010 cf837fa4 00000000 cf837f94
[    0.294494] 7f80: c0403c50 c03e11a5 00000000 c03e7601 c014bf99 00000000 00000004 00000000
[    0.303009] 7fa0: 00000000 12345678 c04037e0 c03e11b1 cf836000 c00086b9 0000018c c042a2dc
[    0.311553] 7fc0: c000d071 c011a19f c042a32c c0055263 c042a32c c04037e0 c0403c50 c000d071
[    0.320068] 7fe0: 00000033 c03df589 00000000 00000000 c03df529 c000d071 0b000ea3 4351a688
[    0.328613] [<c0015ff4>] (gpmc_cs_reserved+0x14/0x20) from [<c0016085>] (gpmc_cs_request+0x35/0xd0)
[    0.338043] [<c0016085>] (gpmc_cs_request+0x35/0xd0) from [<c03e7601>] (am335x_evm_init+0x12d/0x1ac)
[    0.347564] [<c03e7601>] (am335x_evm_init+0x12d/0x1ac) from [<c03e11b1>] (customize_machine+0xd/0x14)
[    0.357147] [<c03e11b1>] (customize_machine+0xd/0x14) from [<c00086b9>] (do_one_initcall+0x69/0x100)
[    0.366668] [<c00086b9>] (do_one_initcall+0x69/0x100) from [<c03df589>] (kernel_init+0x61/0xd8)
[    0.375762] [<c03df589>] (kernel_init+0x61/0xd8) from [<c000d071>] (kernel_thread_exit+0x1/0x6)
[    0.384826] Code: fa03 f000 4b02 681b (691b) 4018
[    0.389892] ---[ end trace 1b75b31a2719ed1c ]---
[    0.394805] Kernel panic - not syncing: Attempted to kill init!

However, I have noticed that when I comment out the gpmc_cs_request(), my test printk() appears in
the boot log *before* the GPMC device appears to be initialised ...

...
[    0.171569] omap_mux_init: Add partition: #1: core, flags: 0
[    0.179077]  omap_i2c.1: alias fck already exists
[    0.184997] gpmc base @ 0x12345678
[    0.188598] hw-breakpoint: debug architecture 0x4 unsupported.
[    0.194915]  omap2_mcspi.1: alias fck already exists
[    0.200256]  omap2_mcspi.2: alias fck already exists
...
[    0.359680] UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)
[    0.366577] NET: Registered protocol family 1
[    0.371673] omap-gpmc omap-gpmc: GPMC revision 6.0
[    0.378356] audit: initializing netlink socket (disabled)
[    0.384063] type=2000 audit(0.380:1): initialized
...

Surely omap-gpmc needs to be setup before any calls such as gpmc_cs_request() ?

Is there a method to delay my test code, or maybe get the omap-gpmc registered earlier ?

Cheers
Mark JACKSON

RE: gpmc_cs_request() causes early boot hang

[Mohammed, Afzal]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 1315 bytes --]

Hi Mark,

On Mon, Sep 24, 2012 at 16:21:40, Mark Jackson wrote:
> On 24/09/12 05:51, Mohammed, Afzal wrote:

> > It seems you are using PSP Kernel.
> > 
> > Invoking omap_init_gpmc before gpmc request should help.
> 
> Okay ... I'm now using earlyprintk and omap_init_gpmc(), but I still get boot hangs.

> Surely omap-gpmc needs to be setup before any calls such as gpmc_cs_request() ?
> 
> Is there a method to delay my test code, or maybe get the omap-gpmc registered earlier ?

Hope below patch helps you (untested)

Regards
Afzal

----8<-------------------

diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
index 1c53c05..a4c6912 100644
--- a/arch/arm/mach-omap2/gpmc.c
+++ b/arch/arm/mach-omap2/gpmc.c
@@ -827,7 +827,19 @@ static struct platform_driver gpmc_driver = {
        },
 };
 
-module_platform_driver(gpmc_driver);
+static __init int gpmc_init(void)
+{
+        return platform_driver_register(&gpmc_driver);
+}
+
+static __exit void gpmc_exit(void)
+{
+        platform_driver_unregister(&gpmc_driver);
+
+}
+
+postcore_initcall(gpmc_init);
+module_exit(gpmc_exit);
 
 int gpmc_suspend(void)
 {
----8<----------------

ÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a­¢f£¢·hšïêÿ‘êçz_è®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨è­Ú&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥

Re: gpmc_cs_request() causes early boot hang

[Mark Jackson]

On 24/09/12 12:13, Mohammed, Afzal wrote:
> Hi Mark,
> 
> On Mon, Sep 24, 2012 at 16:21:40, Mark Jackson wrote:
>> On 24/09/12 05:51, Mohammed, Afzal wrote:
> 
>>> It seems you are using PSP Kernel.
>>>
>>> Invoking omap_init_gpmc before gpmc request should help.
>>
>> Okay ... I'm now using earlyprintk and omap_init_gpmc(), but I still get boot hangs.
> 
>> Surely omap-gpmc needs to be setup before any calls such as gpmc_cs_request() ?
>>
>> Is there a method to delay my test code, or maybe get the omap-gpmc registered earlier ?
> 
> Hope below patch helps you (untested)
> 
> Regards
> Afzal
> 
> ----8<-------------------
> 
> diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
> index 1c53c05..a4c6912 100644
> --- a/arch/arm/mach-omap2/gpmc.c
> +++ b/arch/arm/mach-omap2/gpmc.c
> @@ -827,7 +827,19 @@ static struct platform_driver gpmc_driver = {
>         },
>  };
>  
> -module_platform_driver(gpmc_driver);
> +static __init int gpmc_init(void)
> +{
> +        return platform_driver_register(&gpmc_driver);
> +}
> +
> +static __exit void gpmc_exit(void)
> +{
> +        platform_driver_unregister(&gpmc_driver);
> +
> +}
> +
> +postcore_initcall(gpmc_init);
> +module_exit(gpmc_exit);
>  
>  int gpmc_suspend(void)
>  {
> ----8<----------------

Perfect !!

I also got it working by adding "late_init()" hooks into arch/arm/kernel/setup.c, but your code is
much simpler.

Regards
Mark J.