On Wed, Mar 18, 2020 at 12:40:23PM -0400, Sasha Levin wrote:
On Mon, Mar 16, 2020 at 12:34:09PM +0100, gregkh@linuxfoundation.org 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@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 1cada2f307665e208a486d7ac2294ed9a6f74a6f Mon Sep 17 00:00:00 2001
From: Linus Walleij linus.walleij@linaro.org 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@ixit.cz Cc: Bjorn Andersson bjorn.andersson@linaro.org Cc: Lina Iyer ilina@codeaurora.org Cc: Stephen Boyd swboyd@chromium.org Cc: stable@vger.kernel.org Fixes: e35a6ae0eb3a ("pinctrl/msm: Setup GPIO chip in hierarchy")
This shouldn't go in 5.4, e35a6ae0eb3a is not there.
Ah, grep failed me, there is another reference to that commit id in a 5.4.y release.
thanks,
greg k-h