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SubjectRe: [PATCH 0/2] Fix debugfs register access while suspended
Hi Geert,

Thanks for your series.

On 2020-01-24 14:29:55 +0100, Geert Uytterhoeven wrote:
> Hi all,
>
> While comparing register values read from debugfs files under
> /sys/kernel/debug/ccree/, I noticed some oddities.
> Apparently there is no guarantee these registers are read from the
> device while it is resumed. This may lead to bogus values, or crashes
> and lock-ups.
>
> This patch series:
> 1. Allows debugfs_create_regset32() to be used for devices whose
> registers must be accessed when resumed,
> 2. Fixes the CCREE driver to make use of this.
>
> I have identified several other drivers that may be affected (i.e.
> using debugfs_create_regset32() and pm_runtime_*()):
> - drivers/gpu/drm/msm/disp/dpu1
> - drivers/usb/dwc3
> - drivers/usb/host/ehci-omap.c
> - drivers/usb/host/ehci-tegra.c
> - drivers/usb/host/ohci-platform.c
> - drivers/usb/host/xhci.c
> - drivers/usb/host/xhci-dbgcap.c
> - drivers/usb/host/xhci-histb.c
> - drivers/usb/host/xhci-hub.c
> - drivers/usb/host/xhci-mtk.c
> - drivers/usb/host/xhci-pci.c
> - drivers/usb/host/xhci-plat.c
> - drivers/usb/host/xhci-tegra.c
> - drivers/usb/mtu3
> - drivers/usb/musb
>
> Some of these call pm_runtime_forbid(), but given the comment "users
> should enable runtime pm using power/control in sysfs", this can be
> overridden from userspace, so these are unsafe, too?
>
> Thanks for your comments!

Looks good to me,

Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>

>
> Geert Uytterhoeven (2):
> debugfs: regset32: Add Runtime PM support
> crypto: ccree - fix debugfs register access while suspended
>
> drivers/crypto/ccree/cc_debugfs.c | 2 ++
> fs/debugfs/file.c | 8 ++++++++
> include/linux/debugfs.h | 1 +
> 3 files changed, 11 insertions(+)
>
> --
> 2.17.1
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds

--
Regards,
Niklas Söderlund

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