On Mon, Mar 16, 2020 at 12:34:09PM +0100, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 1cada2f307665e208a486d7ac2294ed9a6f74a6f Mon Sep 17 00:00:00 2001
From: Linus Walleij <linus.walleij@xxxxxxxxxx>
Date: Mon, 9 Mar 2020 16:26:04 +0100
Subject: [PATCH] pinctrl: qcom: Assign irq_eoi conditionally
The hierarchical parts of MSM pinctrl/GPIO is only
used when the device tree has a "wakeup-parent" as
a phandle, but the .irq_eoi is anyway assigned leading
to semantic problems on elder Qualcomm chipsets.
When the drivers/mfd/qcom-pm8xxx.c driver calls
chained_irq_exit() that call will in turn call chip->irq_eoi()
which is set to irq_chip_eoi_parent() by default on a
hierachical IRQ chip, and the parent is pinctrl-msm.c
so that will in turn unconditionally call
irq_chip_eoi_parent() again, but its parent is invalid
so we get the following crash:
Unnable to handle kernel NULL pointer dereference at
virtual address 00000010
pgd = (ptrval)
[00000010] *pgd=00000000
Internal error: Oops: 5 [#1] PREEMPT SMP ARM
(...)
PC is at irq_chip_eoi_parent+0x4/0x10
LR is at pm8xxx_irq_handler+0x1b4/0x2d8
If we solve this crash by avoiding to call up to
irq_chip_eoi_parent(), the machine will hang and get
reset by the watchdog, because of semantic issues,
probably inside irq_chip.
As a solution, just assign the .irq_eoi conditionally if
we are actually using a wakeup parent.
Cc: David Heidelberg <david@xxxxxxx>
Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Cc: Lina Iyer <ilina@xxxxxxxxxxxxxx>
Cc: Stephen Boyd <swboyd@xxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: e35a6ae0eb3a ("pinctrl/msm: Setup GPIO chip in hierarchy")
This shouldn't go in 5.4, e35a6ae0eb3a is not there.
--
Thanks,
Sasha
