Re: [PATCH -next] serial: etraxfs-uart: Fix crash

Uwe Kleine-König
2015-11-02T15:39:50Z

On Mon, Nov 02, 2015 at 06:29:36AM -0800, Guenter Roeck wrote:
> On 11/01/2015 11:37 PM, Uwe Kleine-König wrote:
> >Hello,
> >
> >On Sun, Nov 01, 2015 at 06:32:56PM -0800, Guenter Roeck wrote:
> >>Since commit 7d8c70d8048c ("serial: mctrl-gpio: rename init function"),
> >>crisv32 either do not build or crash as follows.
> >>
> >>Unable to handle kernel NULL pointer dereference
> >>Linux 4.3.0-rc7-next-20151101 #1 Sun Nov 1 11:41:28 PST 2015
> >>...
> >>Call Trace: [<c0004a0e>] show_stack+0x0/0x9e
> >>[<c004c0c0>] printk+0x0/0x2c
> >>[<c00059d4>] show_registers+0x14a/0x1c2
> >>[<c004c0c0>] printk+0x0/0x2c
> >>[<c0004b52>] die_if_kernel+0x7c/0x9e
> >>[<c0005346>] do_page_fault+0x32e/0x3e6
> >>[<c01dc59c>] of_get_property+0x0/0x2c
> >>[<c01e0558>] of_irq_parse_raw+0x12a/0x376
> >>[<c01dc59c>] of_get_property+0x0/0x2c
> >>[<c0053aca>] get_page_from_freelist+0x73e/0x856
> >>[<c01dc59c>] of_get_property+0x0/0x2c
> >>[<c0008912>] d_mmu_refill+0x10a/0x112
> >>[<c01b488c>] devm_kmalloc+0x40/0x56
> >>[<c01b47d0>] add_dr+0xc/0x1c
> >>[<c01b4800>] devm_add_action+0x2/0x4e
> >>[<c01abdbc>] mctrl_gpio_init_noauto+0x1c/0x76
> >>[<c01abf9e>] mctrl_gpio_init+0x22/0x110
> >
> >There should be a warning at compile time about mismatching parameters.
> >
> >>The function call in the etraxfs-uart driver was not renamed,
> >>possibly due to interference with commit 7b9c5162c182 ("serial:
> >>etraxfs-uart: use mctrl_gpio helpers for handling modem signals").
> >
> >Yes. BTW, 7b9c5162c182 looks broken, too, because the interrupt handling
> >is missing.
> >
>
> I can not comment on that; all I can say is that it works for me with qemu.
What does "works for me" mean? You get output on the qemu console? Fine,
but that also works if you don't do any handshaking at all I guess.

Best regards
Uwe

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