Thread (3 messages) flat view 3 messages, 2 authors, 2020-01-10

Re: [PATCH v3] efi: arm: defer probe of PCIe backed efifb on DT systems

From: Saravana Kannan <hidden>
Date: 2020-01-10 17:06:44
Also in: linux-efi, lkml

On Thu, Jan 9, 2020 at 10:41 PM Ard Biesheuvel
[off-list ref] wrote:
On Fri, 10 Jan 2020 at 04:01, Saravana Kannan [off-list ref] wrote:
quoted
From: Ard Biesheuvel <ardb@kernel.org>

The new of_devlink support breaks PCIe probing on ARM platforms booting
via UEFI if the firmware exposes a EFI framebuffer that is backed by a
PCI device. The reason is that the probing order gets reversed,
resulting in a resource conflict on the framebuffer memory window when
the PCIe probes last, causing it to give up entirely.

Given that we rely on PCI quirks to deal with EFI framebuffers that get
moved around in memory, we cannot simply drop the memory reservation, so
instead, let's use the device link infrastructure to register this
dependency, and force the probing to occur in the expected order.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Co-developed-by: Saravana Kannan <redacted>
Signed-off-by: Saravana Kannan <redacted>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
---

v1 -> v2:
- Rewrote the device linking part to not depend on initcall ordering
v2 -> v3:
- Added const and check for CONFIG_PCI
Thanks. I've queued this version in efi/next for v5.6
Awesome, thanks!

-Saravana

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help