Re: [PATCH] iio: imu: st_lsm6dsx: replace underscore with hyphen in device name

[Martin Kepplinger <martin.kepplinger@puri.sm>]

On 03.09.19 14:43, Jonathan Cameron wrote:
> +CC Greg as fix for a patch in my outstanding pull request.
> 
> On Tue, 3 Sep 2019 07:18:02 +0200
> Martin Kepplinger <martin.kepplinger@puri.sm> wrote:
> 
>> With the underscore character in the lsm9ds1_imu device name, we get the
>> following error below, so use a dash, just like the other device names do too.
>>
>> [    3.961399] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000018
>> [    4.010581] Mem abort info:
>> [    4.013838]   ESR = 0x96000004
>> [    4.023602]   Exception class = DABT (current EL), IL = 32 bits
>> [    4.047993]   SET = 0, FnV = 0
>> [    4.052690]   EA = 0, S1PTW = 0
>> [    4.056015] Data abort info:
>> [    4.059020]   ISV = 0, ISS = 0x00000004
>> [    4.080106]   CM = 0, WnR = 0
>> [    4.085237] user pgtable: 4k pages, 48-bit VAs, pgdp=00000000e4f61000
>> [    4.092194] [0000000000000018] pgd=0000000000000000
>> [    4.097474] Internal error: Oops: 96000004 [#1] PREEMPT SMP
>> [    4.103286] Modules linked in: tcpci st_sensors st_lsm6dsx_i2c(+) tcpm st_lsm6dsx industrialio_triggered_buffer kfifo_buf vcnl4000 roles typec goodix snd_soc_sgtl5000 bq25890_charger snvs_pwrkey imx_sdma virt_dma qoriq_thermal imx2_wdt snd_soc_fsl_sai aes_ce_blk imx_pcm_dma crypto_simd watchdog crct10dif_ce ghash_ce sha2_ce snd_soc_simple_card snd_soc_gtm601 snd_soc_simple_card_utils sha1_ce snd_soc_core snd_pcm_dmaengine snd_pcm snd_timer snd soundcore gpio_vibra usb_f_acm u_serial usb_f_rndis g_multi usb_f_mass_storage u_ether libcomposite ip_tables x_tables ipv6 nf_defrag_ipv6 xhci_plat_hcd xhci_hcd usbcore dwc3 ulpi udc_core usb_common phy_fsl_imx8mq_usb
>> [    4.105389] bq25890-charger 0-006b: Capacity for 3784000 is 86%
>> [    4.164061] CPU: 1 PID: 344 Comm: systemd-udevd Tainted: G        W         5.3.0-rc2-g24e3d989d49f-dirty #161
>> [    4.164063] Hardware name: Purism Librem 5 devkit (DT)
>> [    4.164067] pstate: 80000005 (Nzcv daif -PAN -UAO)
>> [    4.164082] pc : st_lsm6dsx_i2c_probe+0x18/0x80 [st_lsm6dsx_i2c]
>> [    4.164093] lr : i2c_device_probe+0x1f0/0x2b8
>> [    4.164094] sp : ffff8000a499f970
>> [    4.164097] x29: ffff8000a499f970 x28: 0000000000000000
>> [    4.164100] x27: ffff000010b70000 x26: ffff8000a499fd68
>> [    4.164104] x25: ffff000010860000 x24: ffff000008a8b038
>> [    4.164108] x23: ffff000008a8b038 x22: ffff000008a8b000
>> [    4.164111] x21: ffff8000a55b2400 x20: ffff000008a89000
>> [    4.164115] x19: ffff8000a55b2400 x18: ffffffffffffffff
>> [    4.164118] x17: 0000000000000000 x16: 0000000000000000
>> [    4.164121] x15: 0000000000040000 x14: 00000000fffffff0
>> [    4.164125] x13: ffff000010b6c898 x12: 0000000000000030
>> [    4.164128] x11: 0000000000000000 x10: 0101010101010101
>> [    4.260542] x9 : fffffffffffffffc x8 : 0000000000000008
>> [    4.266073] x7 : 0000000000000004 x6 : 1e0e1a00f2ade4ef
>> [    4.271605] x5 : 6f642d72001a0e1e x4 : 8080808000000000
>> [    4.277136] x3 : 0000000000000000 x2 : ffff000008a8a000
>> [    4.282667] x1 : 0000000000000000 x0 : ffff8000a55b2400
>> [    4.288199] Call trace:
>> [    4.290753]  st_lsm6dsx_i2c_probe+0x18/0x80 [st_lsm6dsx_i2c]
>> [    4.296648]  i2c_device_probe+0x1f0/0x2b8
>> [    4.300825]  really_probe+0x168/0x368
>> [    4.304638]  driver_probe_device.part.2+0x10c/0x128
>> [    4.309716]  device_driver_attach+0x74/0xa0
>> [    4.314071]  __driver_attach+0x84/0x130
>> [    4.318065]  bus_for_each_dev+0x68/0xc8
>> [    4.322058]  driver_attach+0x20/0x28
>> [    4.325780]  bus_add_driver+0xd4/0x1f8
>> [    4.329683]  driver_register+0x60/0x110
>> [    4.333677]  i2c_register_driver+0x44/0x98
>> [    4.337944]  st_lsm6dsx_driver_init+0x1c/0x1000 [st_lsm6dsx_i2c]
>> [    4.344200]  do_one_initcall+0x58/0x1a8
>> [    4.348195]  do_init_module+0x54/0x1d4
>> [    4.352098]  load_module+0x1998/0x1c40
>> [    4.356001]  __se_sys_finit_module+0xc0/0xd8
>> [    4.360446]  __arm64_sys_finit_module+0x14/0x20
>> [    4.365166]  el0_svc_common.constprop.0+0xb0/0x168
>> [    4.370154]  el0_svc_handler+0x18/0x20
>> [    4.374056]  el0_svc+0x8/0xc
>> [    4.377059] Code: d2800003 910003fd a90153f3 aa0003f3 (f9400c34)
>> [    4.383406] ---[ end trace 6dfe010c028e3371 ]---
>>
> 
>> Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>
> Fixes: a106864fd667 ("iio: imu: st_lsm6dsx: add support for accel/gyro unit of lsm9ds1")
> 
> Thanks Martin.  This one is entirely my fault for messing up tweaking
> that naming.  I should have bounced the patch back for another round
> rather than thinking "it's trivial, what could possibly go wrong!"

I wouldn't have thought but even your trivial change would probably have
deserved to be a separate commit. That would've saved time.

but np. worse things have happened. I'm glad to have it fixed. thanks
for the quick response.

                       martin

> 
> On basis Greg may prefer to pick this one directly:
> 
> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
> Convenient lore.kernel.org link.
> 
> https://lore.kernel.org/linux-iio/20190903051802.22716-1-martin.kepplinger@puri.sm/T/#u
> 
> 
> If not I'll pick it up for first set of fixes post rc1.
> 
> As for the question below, I've not taken a look yet and certainly seems
> an odd result!
> 
> Thanks,
> 
> Jonathan
> 
> 
> 
>> ---
>>
>> While this patch fixes my (formerly already mentioned) issue, it's
>> a question actually: Why does is this underscore character a problem?
>>
>> thanks,
>>
>>                         martin
>>
>>
>>
>>  drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
>> index 5e3cd96b0059..80e42c7dbcbe 100644
>> --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
>> +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
>> @@ -24,7 +24,7 @@
>>  #define ST_LSM6DSR_DEV_NAME	"lsm6dsr"
>>  #define ST_LSM6DS3TRC_DEV_NAME	"lsm6ds3tr-c"
>>  #define ST_ISM330DHCX_DEV_NAME	"ism330dhcx"
>> -#define ST_LSM9DS1_DEV_NAME	"lsm9ds1_imu"
>> +#define ST_LSM9DS1_DEV_NAME	"lsm9ds1-imu"
>>  
>>  enum st_lsm6dsx_hw_id {
>>  	ST_LSM6DS3_ID,
> 
>