openwrt/target/linux/mvebu/patches-5.15/710-v6.2-phy-marvell-phy-mvebu-a3700-comphy-Reset-COMPHY-regi.patch
Michal Hrusecky f6b46c9269 mvebu: backport upstream patch to fix COMPHY reset
Upstream commit [1] included in the Linux kernel version 6.2 was
backported to Linux kernels 6.1.4, 6.0.18. It should be possible that it
is going to be backported even to the 5.15 series, but before it happens,
let's include it here.

It was discovered that on SOC Marvell Armada 3720, which is using e.g.
Turris MOX, and if you are also using it with older ARM Trusted Firmware
v1.5, it is not possible to detect connected USB 3.0 devices, but they
are working just fine when connected with USB 2.0 cable. This patch
fixes it.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/phy/marvell/phy-mvebu-a3700-comphy.c?id=b01d622d76134e9401970ffd3fbbb9a7051f976a

Reviewed-by: Robert Marko <robimarko@gmail.com>
Signed-off-by: Michal Hrusecky <michal.hrusecky@turris.com>
Signed-off-by: Josef Schlehofer <pepe.schlehofer@gmail.com>
[improve commit description, added tag to the patch]
2023-01-11 21:56:36 +01:00

51 lines
2.2 KiB
Diff

From b01d622d76134e9401970ffd3fbbb9a7051f976a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>
Date: Tue, 20 Sep 2022 14:11:54 +0200
Subject: [PATCH] phy: marvell: phy-mvebu-a3700-comphy: Reset COMPHY registers
before USB 3.0 power on
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Turris MOX board with older ARM Trusted Firmware version v1.5 is not able
to detect any USB 3.0 device connected to USB-A port on Mox-A module after
commit 0a6fc70d76bd ("phy: marvell: phy-mvebu-a3700-comphy: Remove broken
reset support"). On the other hand USB 2.0 devices connected to the same
USB-A port are working fine.
It looks as if the older firmware configures COMPHY registers for USB 3.0
somehow incompatibly for kernel driver. Experiments show that resetting
COMPHY registers via setting SFT_RST auto-clearing bit in COMPHY_SFT_RESET
register fixes this issue.
Reset the COMPHY in mvebu_a3700_comphy_usb3_power_on() function as a first
step after selecting COMPHY lane and USB 3.0 function. With this change
Turris MOX board can successfully detect USB 3.0 devices again.
Before the above mentioned commit this reset was implemented in PHY reset
method, so this is the reason why there was no issue with older firmware
version then.
Fixes: 0a6fc70d76bd ("phy: marvell: phy-mvebu-a3700-comphy: Remove broken reset support")
Reported-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Pali Rohár <pali@kernel.org>
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20220920121154.30115-1-pali@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
---
drivers/phy/marvell/phy-mvebu-a3700-comphy.c | 3 +++
1 file changed, 3 insertions(+)
--- a/drivers/phy/marvell/phy-mvebu-a3700-comphy.c
+++ b/drivers/phy/marvell/phy-mvebu-a3700-comphy.c
@@ -826,6 +826,9 @@ mvebu_a3700_comphy_usb3_power_on(struct
if (ret)
return ret;
+ /* COMPHY register reset (cleared automatically) */
+ comphy_lane_reg_set(lane, COMPHY_SFT_RESET, SFT_RST, SFT_RST);
+
/*
* 0. Set PHY OTG Control(0x5d034), bit 4, Power up OTG module The
* register belong to UTMI module, so it is set in UTMI phy driver.