On 31 January 2017 21:18:09 GMT+00:00, "Ken.Lin" <ken.lin@xxxxxxxxxxxxx> wrote: >Hi Daniel, > >Thank you for your feedback. >We use a mpl3115A2 sensor for our project platform. > Hmm. That shouldn't be creating the attribute for you to read in the first place. Are we talking about a modified driver? > >Cheers, >Ken Lin > >> -----Original Message----- >> From: Daniel Baluta [mailto:daniel.baluta@xxxxxxxxx] >> Sent: Tuesday, January 31, 2017 1:05 PM >> To: Ken.Lin >> Cc: jic23@xxxxxxxxxx; peda@xxxxxxxxxx; knaack.h@xxxxxx; >> pmeerw@xxxxxxxxxx; linux-iio@xxxxxxxxxxxxxxx; >linux-kernel@xxxxxxxxxxxxxxx; >> Akshay Bhat; Peter.Stretz; Peter.Chiang >> Subject: Re: kernel 4.10-rcx iio helper question >> >> On Tue, Jan 31, 2017 at 8:19 PM, Ken.Lin <ken.lin@xxxxxxxxxxxxx> >wrote: >> > Hi, >> > >> > I find the latest kernel introduces new iio sys attributes. >> > https://patchwork.kernel.org/patch/9391771/ >> > https://patchwork.kernel.org/patch/9391259/ >> > >> > Is there anyone has some ideas about how the new iio sys attribute >- >> in_pressure_scale_available works? >> > I'm not sure if it's the regression issue or it's just the usage >issue or something >> when I tried to read in_pressure_scale_available attribute. >> > >> > # cat /sys/bus/iio/devices/iio\:device1/in_pressure_scale_available >> > Segmentation fault >> > >> > [ 3785.077014] Unable to handle kernel NULL pointer dereference at >> > virtual address 00000000 [ 3785.085138] pgd = ecc3c000 [ >3785.087929] >> > [00000000] *pgd=87f91831 [ 3785.091563] Internal error: Oops: >80000007 >> > [#1] SMP ARM [ 3785.096806] Modules linked in: >> > [ 3785.099892] CPU: 1 PID: 1051 Comm: cat Not tainted >> > 4.10.0-rc5-00009-gffd8858-dirty #3 [ 3785.107740] Hardware name: >> > Freescale i.MX6 Quad/DualLite (Device Tree) [ 3785.114285] task: >> > ed54ec00 task.stack: ee2bc000 [ 3785.118834] PC is at 0x0 [ >> > 3785.121397] LR is at iio_read_channel_info_avail+0x40/0x280 >> > [ 3785.126992] pc : [<00000000>] lr : [<c06fbc1c>] psr: >a0070013 >> > [ 3785.126992] sp : ee2bdda8 ip : 00000000 fp : ee2bddf4 [ >> > 3785.138490] r10: c0a53c74 r9 : ed79f000 r8 : ee8d1018 [ >> > 3785.143733] r7 : 00001000 r6 : 00000fff r5 : ee8b9a00 r4 : >> > ed79f000 [ 3785.150276] r3 : ee2bddc4 r2 : ee2bddbc r1 : c0a86dcc >> > r0 : ee8d1000 [ 3785.156820] Flags: NzCv IRQs on FIQs on Mode >> > SVC_32 ISA ARM Segment none [ 3785.163971] Control: 10c5387d >Table: >> > 3cc3c04a DAC: 00000051 [ 3785.169734] Process cat (pid: 1051, >stack >> > limit = 0xee2bc210) [ 3785.175497] Stack: (0xee2bdda8 to >0xee2be000) >> > [ 3785.179880] dda0: ee2bddc0 00000002 c016d720 >c016d394 >> ed54ec00 00000000 >> > [ 3785.188084] ddc0: 60070013 ed413780 00000001 edffd480 ee8b9a00 >> > 00000fff 00001000 ee8d1018 [ 3785.196286] dde0: ed79f000 c0a53c74 >> > ee2bde0c ee2bddf8 c0513c58 c06fbbe8 edffd480 edffd540 [ >3785.204488] >> > de00: ee2bde3c ee2bde10 c0293474 c0513c40 c02933e4 ee2bde60 >00000001 >> > ed413780 [ 3785.212688] de20: 00000001 ed413780 00000000 edffd480 >> > ee2bde4c ee2bde40 c0291d00 c02933f0 [ 3785.220889] de40: ee2bde9c >> > ee2bde50 c024679c c0291ce0 edffd4b0 b6e37000 00020000 ee2bdf78 [ >> > 3785.229089] de60: 00000000 00000000 ed54ec00 ed013200 00000817 >> > c0a111fc edffd540 ed413780 [ 3785.237289] de80: b6e37000 00020000 >> > 00020000 ee2bdf78 ee2bded4 ee2bdea0 c0292890 c0246604 [ >3785.245491] >> > dea0: c0117940 c016ba50 00000025 c0a111fc b6e37000 ed413780 >ee2bdf78 >> > 00020000 [ 3785.253691] dec0: ee2bc000 b6e37000 ee2bdf44 ee2bded8 >> > c021d158 c0292770 c0117764 b6e36004 [ 3785.261893] dee0: c0f0d7c4 >> > ee2bdfb0 b6f89228 00021008 ee2bdfac ee2bdf00 c0101374 c0117770 [ >> > 3785.270093] df00: 00000000 00000000 ee2bc000 00000000 ee2bdf34 >> > ee2bdf20 c016ba04 c0171080 [ 3785.278292] df20: 00000000 00020000 >> > ed413780 b6e37000 00000000 ee2bdf78 ee2bdf74 ee2bdf48 [ >3785.286493] >> > df40: c021e7a0 c021d130 c023e300 c023e280 ee2bdf74 00000000 >00000000 >> > ed413780 [ 3785.294693] df60: ed413780 00020000 ee2bdfa4 ee2bdf78 >> c021e870 c021e71c 00000000 00000000 [ 3785.302892] df80: 00020000 >> 00020000 b6e37000 00000003 c0108084 00000000 00000000 ee2bdfa8 [ >> 3785.311092] dfa0: c0107ee0 c021e838 00020000 00020000 00000003 >> b6e37000 00020000 0001a2b4 [ 3785.319292] dfc0: 00020000 00020000 >> b6e37000 00000003 7fffe000 00000000 00000000 00020000 [ 3785.327492] >> dfe0: 00000000 be98eb4c 0000c740 b6f1985c 60070010 00000003 00000000 >> 00000000 [ 3785.335679] Backtrace: >> > [ 3785.338175] [<c06fbbdc>] (iio_read_channel_info_avail) from >> > [<c0513c58>] (dev_attr_show+0x24/0x50) [ 3785.347162] r10:c0a53c74 >> > r9:ed79f000 r8:ee8d1018 r7:00001000 r6:00000fff r5:ee8b9a00 [ >> > 3785.355005] r4:edffd480 [ 3785.357571] [<c0513c34>] >(dev_attr_show) >> > from [<c0293474>] (sysfs_kf_seq_show+0x90/0x110) [ 3785.365764] >> > r5:edffd540 r4:edffd480 [ 3785.369365] [<c02933e4>] >> > (sysfs_kf_seq_show) from [<c0291d00>] (kernfs_seq_show+0x2c/0x30) [ >> > 3785.377652] r10:edffd480 r9:00000000 r8:ed413780 r7:00000001 >> > r6:ed413780 r5:00000001 [ 3785.385498] r4:ee2bde60 r3:c02933e4 [ >> > 3785.389101] [<c0291cd4>] (kernfs_seq_show) from [<c024679c>] >> > (seq_read+0x1a4/0x4e0) [ 3785.396780] [<c02465f8>] (seq_read) from >> > [<c0292890>] (kernfs_fop_read+0x12c/0x1cc) [ 3785.404460] >> > r10:ee2bdf78 r9:00020000 r8:00020000 r7:b6e37000 r6:ed413780 >> > r5:edffd540 [ 3785.412303] r4:c0a111fc [ 3785.414862] [<c0292764>] >> > (kernfs_fop_read) from [<c021d158>] (__vfs_read+0x34/0x118) [ >> > 3785.422627] r10:b6e37000 r9:ee2bc000 r8:00020000 r7:ee2bdf78 >> > r6:ed413780 r5:b6e37000 [ 3785.430470] r4:c0a111fc [ 3785.433029] >> > [<c021d124>] (__vfs_read) from [<c021e7a0>] (vfs_read+0x90/0x11c) [ >> > 3785.440185] r8:ee2bdf78 r7:00000000 r6:b6e37000 r5:ed413780 >> > r4:00020000 [ 3785.446909] [<c021e710>] (vfs_read) from >[<c021e870>] >> > (SyS_read+0x44/0x90) [ 3785.453804] r8:00020000 r7:ed413780 >> > r6:ed413780 r5:00000000 r4:00000000 [ 3785.460537] [<c021e82c>] >> > (SyS_read) from [<c0107ee0>] (ret_fast_syscall+0x0/0x1c) [ >> > 3785.468042] r10:00000000 r8:c0108084 r7:00000003 r6:b6e37000 >> > r5:00020000 r4:00020000 [ 3785.476238] Code: bad PC value [ >> > 3785.490358] ---[ end trace 9c4938ccd0389004 ]--- >> >> >> Hi Ken, >> >> What sensor are you using? >> >> -- >> This message has been scanned for viruses and dangerous content by >> MailScanner, and is believed to be clean. > > >-- >This message has been scanned for viruses and >dangerous content by MailScanner, and is >believed to be clean. -- Sent from my Android device with K-9 Mail. Please excuse my brevity. -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
