Re: [PATCH v8 0/2] PCI: brcmstb: Configure appropriate HW CLKREQ# mode

From: Cyril Brulebois
Date: Sun Nov 26 2023 - 15:20:01 EST


Hi Jim,

Jim Quinlan <james.quinlan@xxxxxxxxxxxx> (2023-11-13):
> V8 -- Un-advertise L1SS capability when in "no-l1ss" mode (Bjorn)
> -- Squashed last two commits of v7 (Bjorn)
> -- Fix DT binding description text wrapping (Bjorn)
> -- Fix incorrect Spec reference (Bjorn)
> s/PCIe Spec/PCIe Express Mini CEM 2.1 specification/
> -- Text substitutions (Bjorn)
> s/WRT/With respect to/
> s/Tclron/T_CLRon/
>
> v7 -- Manivannan Sadhasivam suggested (a) making the property look like a
> network phy-mode and (b) keeping the code simple (not counting clkreq
> signal appearances, un-advertising capabilites, etc). This is
> what I have done. The property is now "brcm,clkreq-mode" and
> the values may be one of "safe", "default", and "no-l1ss". The
> default setting is to employ the most capable power savings mode.

Still:

Tested-by: Cyril Brulebois <cyril@xxxxxxxxxxx>


I've just run my big test matrix again, and I can confirm everything is
still looking good with the updated series and the updated base commit.


Test setup:
-----------

- using a $CM with the 20230111 EEPROM
- on the same CM4 IO Board
- with a $PCIE board (PCIe to multiple USB ports)
- and the same Samsung USB flash drive + Logitech keyboard.

where $CM is one of:

- CM4 Lite Rev 1.0
- CM4 8/32 Rev 1.0
- CM4 4/32 Rev 1.1

and $PCIE is one of:

- SupaHub PCE6U1C-R02, VER 006
- SupaHub PCE6U1C-R02, VER 006S
- Waveshare VIA VL805/806-based


Results:
--------

1. With an unpatched kernel, I'm getting either a successful boot
*without* seeing the devices plugged on the PCIe-to-USB board
or the dreaded SError in most cases, using a locally-built
v6.4-rc7-194-g8a28a0b6f1a1d kernel.

2. With a patched kernel (v6.6-15365-g305230142ae0 + this series),
for all $CM/$PCIE combinations, I'm getting a system that boots,
sees the flash drive, and gives decent read/write performance on
it (plus a functional keyboard).


Cheers,
--
Cyril Brulebois (kibi@xxxxxxxxxx) <https://debamax.com/>
D-I release manager -- Release team member -- Freelance Consultant

Attachment: signature.asc
Description: PGP signature