* [PATCH 1/3] phy: apple: atc: Support DUMMY PIPEHANDLER state in configure_pipehandler
2026-08-21 13:50 [PATCH 0/3] phy: apple: atc: Prepare USB3-via-4 tunneling Sven Peter
@ 2026-08-21 13:50 ` Sven Peter
2026-08-21 13:50 ` [PATCH 2/3] phy: apple: atc: Factor out the PIPE mux sequence Sven Peter
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Sven Peter @ 2026-08-21 13:50 UTC (permalink / raw)
To: Janne Grunau, Neal Gompa, Vinod Koul, Neil Armstrong
Cc: asahi, linux-arm-kernel, linux-phy, linux-kernel, Sven Peter,
Paul Cristian, stable
For both Thunderbolt and DisplayPort atcphy_configure_pipehandler is
reached with a request to switch to the DUMMY state (i.e. usb2 only).
With the current code this breaks USB2 when all four SS lanes are used
for DisplayPort AltMode because the -EINVAL is passed all the way back
to the phy_set_mode() call which results in tearing down xhci and dwc3
again.
Let's actually handle that case correctly and also drop the default from
the switch such that we get a compiler warning if another pipehandler
state is ever added and forgotten here.
Reported-by: Paul Cristian <p4ulcristian@gmail.com>
Closes: https://github.com/AsahiLinux/linux/pull/515
Fixes: 8e98ca1e74db ("phy: apple: Add Apple Type-C PHY")
Cc: stable@vger.kernel.org
Signed-off-by: Sven Peter <sven@kernel.org>
---
drivers/phy/apple/atc.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/phy/apple/atc.c b/drivers/phy/apple/atc.c
index 4156fabad742..a3162f25e6cd 100644
--- a/drivers/phy/apple/atc.c
+++ b/drivers/phy/apple/atc.c
@@ -1121,7 +1121,7 @@ static int atcphy_configure_pipehandler_dummy(struct apple_atcphy *atcphy)
static int atcphy_configure_pipehandler(struct apple_atcphy *atcphy, bool host)
{
- int ret;
+ int ret = -EINVAL;
lockdep_assert_held(&atcphy->lock);
@@ -1136,8 +1136,10 @@ static int atcphy_configure_pipehandler(struct apple_atcphy *atcphy, bool host)
ret = atcphy_configure_pipehandler_dummy(atcphy);
atcphy->pipehandler_up = false;
break;
- default:
- ret = -EINVAL;
+ case ATCPHY_PIPEHANDLER_STATE_DUMMY:
+ ret = atcphy_configure_pipehandler_dummy(atcphy);
+ atcphy->pipehandler_up = false;
+ break;
}
return ret;
--
2.55.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 2/3] phy: apple: atc: Factor out the PIPE mux sequence
2026-08-21 13:50 [PATCH 0/3] phy: apple: atc: Prepare USB3-via-4 tunneling Sven Peter
2026-08-21 13:50 ` [PATCH 1/3] phy: apple: atc: Support DUMMY PIPEHANDLER state in configure_pipehandler Sven Peter
@ 2026-08-21 13:50 ` Sven Peter
2026-08-21 13:50 ` [PATCH 3/3] phy: apple: atc: Implement the USB4 pipehandler state Sven Peter
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Sven Peter @ 2026-08-21 13:50 UTC (permalink / raw)
To: Janne Grunau, Neal Gompa, Vinod Koul, Neil Armstrong
Cc: asahi, linux-arm-kernel, linux-phy, linux-kernel, Sven Peter
This sequence is already used in three places and we're about to add a
fourth copy so let's factor it out to a helper. No functional change.
Signed-off-by: Sven Peter <sven@kernel.org>
---
drivers/phy/apple/atc.c | 46 +++++++++++++++++++---------------------------
1 file changed, 19 insertions(+), 27 deletions(-)
diff --git a/drivers/phy/apple/atc.c b/drivers/phy/apple/atc.c
index a3162f25e6cd..96158d348656 100644
--- a/drivers/phy/apple/atc.c
+++ b/drivers/phy/apple/atc.c
@@ -972,6 +972,19 @@ static int atcphy_pipehandler_check(struct apple_atcphy *atcphy)
return 0;
}
+static void atcphy_pipehandler_set_mux(struct apple_atcphy *atcphy, u32 data, u32 clk)
+{
+ mask32(atcphy->regs.pipehandler + PIPEHANDLER_MUX_CTRL, PIPEHANDLER_MUX_CTRL_CLK,
+ FIELD_PREP(PIPEHANDLER_MUX_CTRL_CLK, PIPEHANDLER_MUX_CTRL_CLK_OFF));
+ udelay(10);
+ mask32(atcphy->regs.pipehandler + PIPEHANDLER_MUX_CTRL, PIPEHANDLER_MUX_CTRL_DATA,
+ FIELD_PREP(PIPEHANDLER_MUX_CTRL_DATA, data));
+ udelay(10);
+ mask32(atcphy->regs.pipehandler + PIPEHANDLER_MUX_CTRL, PIPEHANDLER_MUX_CTRL_CLK,
+ FIELD_PREP(PIPEHANDLER_MUX_CTRL_CLK, clk));
+ udelay(10);
+}
+
static int atcphy_configure_pipehandler_usb3(struct apple_atcphy *atcphy, bool host)
{
int ret;
@@ -1054,15 +1067,8 @@ static int atcphy_configure_pipehandler_usb3(struct apple_atcphy *atcphy, bool h
}
/* Configure PIPE mux to USB3 PHY */
- mask32(atcphy->regs.pipehandler + PIPEHANDLER_MUX_CTRL, PIPEHANDLER_MUX_CTRL_CLK,
- FIELD_PREP(PIPEHANDLER_MUX_CTRL_CLK, PIPEHANDLER_MUX_CTRL_CLK_OFF));
- udelay(10);
- mask32(atcphy->regs.pipehandler + PIPEHANDLER_MUX_CTRL, PIPEHANDLER_MUX_CTRL_DATA,
- FIELD_PREP(PIPEHANDLER_MUX_CTRL_DATA, PIPEHANDLER_MUX_CTRL_DATA_USB3));
- udelay(10);
- mask32(atcphy->regs.pipehandler + PIPEHANDLER_MUX_CTRL, PIPEHANDLER_MUX_CTRL_CLK,
- FIELD_PREP(PIPEHANDLER_MUX_CTRL_CLK, PIPEHANDLER_MUX_CTRL_CLK_USB3));
- udelay(10);
+ atcphy_pipehandler_set_mux(atcphy, PIPEHANDLER_MUX_CTRL_DATA_USB3,
+ PIPEHANDLER_MUX_CTRL_CLK_USB3);
/* Remove link detection override */
clear32(atcphy->regs.pipehandler + PIPEHANDLER_OVERRIDE, PIPEHANDLER_OVERRIDE_RXVALID);
@@ -1097,15 +1103,8 @@ static int atcphy_configure_pipehandler_dummy(struct apple_atcphy *atcphy)
dev_warn(atcphy->dev, "Failed to lock pipehandler");
/* Switch to dummy PHY */
- mask32(atcphy->regs.pipehandler + PIPEHANDLER_MUX_CTRL, PIPEHANDLER_MUX_CTRL_CLK,
- FIELD_PREP(PIPEHANDLER_MUX_CTRL_CLK, PIPEHANDLER_MUX_CTRL_CLK_OFF));
- udelay(10);
- mask32(atcphy->regs.pipehandler + PIPEHANDLER_MUX_CTRL, PIPEHANDLER_MUX_CTRL_DATA,
- FIELD_PREP(PIPEHANDLER_MUX_CTRL_DATA, PIPEHANDLER_MUX_CTRL_DATA_DUMMY));
- udelay(10);
- mask32(atcphy->regs.pipehandler + PIPEHANDLER_MUX_CTRL, PIPEHANDLER_MUX_CTRL_CLK,
- FIELD_PREP(PIPEHANDLER_MUX_CTRL_CLK, PIPEHANDLER_MUX_CTRL_CLK_DUMMY));
- udelay(10);
+ atcphy_pipehandler_set_mux(atcphy, PIPEHANDLER_MUX_CTRL_DATA_DUMMY,
+ PIPEHANDLER_MUX_CTRL_CLK_DUMMY);
ret = atcphy_pipehandler_unlock(atcphy);
if (ret)
@@ -1149,15 +1148,8 @@ static void atcphy_setup_pipehandler(struct apple_atcphy *atcphy)
{
lockdep_assert_held(&atcphy->lock);
- mask32(atcphy->regs.pipehandler + PIPEHANDLER_MUX_CTRL, PIPEHANDLER_MUX_CTRL_CLK,
- FIELD_PREP(PIPEHANDLER_MUX_CTRL_CLK, PIPEHANDLER_MUX_CTRL_CLK_OFF));
- udelay(10);
- mask32(atcphy->regs.pipehandler + PIPEHANDLER_MUX_CTRL, PIPEHANDLER_MUX_CTRL_DATA,
- FIELD_PREP(PIPEHANDLER_MUX_CTRL_DATA, PIPEHANDLER_MUX_CTRL_DATA_DUMMY));
- udelay(10);
- mask32(atcphy->regs.pipehandler + PIPEHANDLER_MUX_CTRL, PIPEHANDLER_MUX_CTRL_CLK,
- FIELD_PREP(PIPEHANDLER_MUX_CTRL_CLK, PIPEHANDLER_MUX_CTRL_CLK_DUMMY));
- udelay(10);
+ atcphy_pipehandler_set_mux(atcphy, PIPEHANDLER_MUX_CTRL_DATA_DUMMY,
+ PIPEHANDLER_MUX_CTRL_CLK_DUMMY);
}
static void atcphy_configure_lanes(struct apple_atcphy *atcphy, enum atcphy_mode mode)
--
2.55.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 3/3] phy: apple: atc: Implement the USB4 pipehandler state
2026-08-21 13:50 [PATCH 0/3] phy: apple: atc: Prepare USB3-via-4 tunneling Sven Peter
2026-08-21 13:50 ` [PATCH 1/3] phy: apple: atc: Support DUMMY PIPEHANDLER state in configure_pipehandler Sven Peter
2026-08-21 13:50 ` [PATCH 2/3] phy: apple: atc: Factor out the PIPE mux sequence Sven Peter
@ 2026-08-21 13:50 ` Sven Peter
2026-09-07 10:45 ` [PATCH 0/3] phy: apple: atc: Prepare USB3-via-4 tunneling Janne Grunau
2026-10-03 15:25 ` Vinod Koul
4 siblings, 0 replies; 6+ messages in thread
From: Sven Peter @ 2026-08-21 13:50 UTC (permalink / raw)
To: Janne Grunau, Neal Gompa, Vinod Koul, Neil Armstrong
Cc: asahi, linux-arm-kernel, linux-phy, linux-kernel, Sven Peter
USB3 tunneled via USB4 requires dwc3's PIPE interface to be switched to
the USB4 NHI which will take care of the tunneling. Add the required
bringup sequence such that USB3 tunnels work once the USB4 NHI is
upstream.
Signed-off-by: Sven Peter <sven@kernel.org>
---
drivers/phy/apple/atc.c | 41 +++++++++++++++++++++++++++++++++++++----
1 file changed, 37 insertions(+), 4 deletions(-)
diff --git a/drivers/phy/apple/atc.c b/drivers/phy/apple/atc.c
index 96158d348656..613bcd0ae886 100644
--- a/drivers/phy/apple/atc.c
+++ b/drivers/phy/apple/atc.c
@@ -1084,6 +1084,41 @@ static int atcphy_configure_pipehandler_usb3(struct apple_atcphy *atcphy, bool h
return 0;
}
+static int atcphy_configure_pipehandler_usb4(struct apple_atcphy *atcphy)
+{
+ int ret;
+
+ ret = atcphy_pipehandler_check(atcphy);
+ if (ret)
+ return ret;
+
+ /* Force disable link detection */
+ clear32(atcphy->regs.pipehandler + PIPEHANDLER_OVERRIDE_VALUES,
+ PIPEHANDLER_OVERRIDE_VAL_RXDETECT0 | PIPEHANDLER_OVERRIDE_VAL_RXDETECT1);
+ set32(atcphy->regs.pipehandler + PIPEHANDLER_OVERRIDE, PIPEHANDLER_OVERRIDE_RXVALID);
+ set32(atcphy->regs.pipehandler + PIPEHANDLER_OVERRIDE, PIPEHANDLER_OVERRIDE_RXDETECT);
+
+ ret = atcphy_pipehandler_lock(atcphy);
+ if (ret) {
+ dev_err(atcphy->dev, "Failed to lock pipehandler\n");
+ return ret;
+ }
+
+ /* Configure PIPE mux to the USB4/Thunderbolt controller */
+ atcphy_pipehandler_set_mux(atcphy, PIPEHANDLER_MUX_CTRL_DATA_USB4,
+ PIPEHANDLER_MUX_CTRL_CLK_USB4);
+
+ /* Remove link detection override */
+ clear32(atcphy->regs.pipehandler + PIPEHANDLER_OVERRIDE, PIPEHANDLER_OVERRIDE_RXVALID);
+ clear32(atcphy->regs.pipehandler + PIPEHANDLER_OVERRIDE, PIPEHANDLER_OVERRIDE_RXDETECT);
+
+ ret = atcphy_pipehandler_unlock(atcphy);
+ if (ret)
+ dev_warn(atcphy->dev, "Failed to unlock pipehandler\n");
+
+ return 0;
+}
+
static int atcphy_configure_pipehandler_dummy(struct apple_atcphy *atcphy)
{
int ret;
@@ -1130,10 +1165,8 @@ static int atcphy_configure_pipehandler(struct apple_atcphy *atcphy, bool host)
atcphy->pipehandler_up = true;
break;
case ATCPHY_PIPEHANDLER_STATE_USB4:
- dev_warn(atcphy->dev,
- "ATCPHY_PIPEHANDLER_STATE_USB4 not implemented; falling back to USB2\n");
- ret = atcphy_configure_pipehandler_dummy(atcphy);
- atcphy->pipehandler_up = false;
+ ret = atcphy_configure_pipehandler_usb4(atcphy);
+ atcphy->pipehandler_up = true;
break;
case ATCPHY_PIPEHANDLER_STATE_DUMMY:
ret = atcphy_configure_pipehandler_dummy(atcphy);
--
2.55.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH 0/3] phy: apple: atc: Prepare USB3-via-4 tunneling
2026-08-21 13:50 [PATCH 0/3] phy: apple: atc: Prepare USB3-via-4 tunneling Sven Peter
` (2 preceding siblings ...)
2026-08-21 13:50 ` [PATCH 3/3] phy: apple: atc: Implement the USB4 pipehandler state Sven Peter
@ 2026-09-07 10:45 ` Janne Grunau
2026-10-03 15:25 ` Vinod Koul
4 siblings, 0 replies; 6+ messages in thread
From: Janne Grunau @ 2026-09-07 10:45 UTC (permalink / raw)
To: Sven Peter
Cc: Neal Gompa, Vinod Koul, Neil Armstrong, asahi, linux-arm-kernel,
linux-phy, linux-kernel, Paul Cristian, stable
On Fri, Aug 21, 2026 at 03:50:26PM +0200, Sven Peter wrote:
> Hi,
>
> This short series first fixes an oversight that prevents USB2 from
> working when DP AltMode with 4 lanes is used. Then it adds the required
> sequence to point dwc3's PIPE interface to the USB4 Native Host
> Interface which I plan to submit soon to support USB3-via-USB4 tunnels.
>
> Best,
>
> Sven
>
> Signed-off-by: Sven Peter <sven@kernel.org>
> ---
> Sven Peter (3):
> phy: apple: atc: Support DUMMY PIPEHANDLER state in configure_pipehandler
> phy: apple: atc: Factor out the PIPE mux sequence
> phy: apple: atc: Implement the USB4 pipehandler state
>
> drivers/phy/apple/atc.c | 91 ++++++++++++++++++++++++++++++++-----------------
> 1 file changed, 59 insertions(+), 32 deletions(-)
Whole series
Reviewed-by: Janne Grunau <j@jannau.net>
Janne
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH 0/3] phy: apple: atc: Prepare USB3-via-4 tunneling
2026-08-21 13:50 [PATCH 0/3] phy: apple: atc: Prepare USB3-via-4 tunneling Sven Peter
` (3 preceding siblings ...)
2026-09-07 10:45 ` [PATCH 0/3] phy: apple: atc: Prepare USB3-via-4 tunneling Janne Grunau
@ 2026-10-03 15:25 ` Vinod Koul
4 siblings, 0 replies; 6+ messages in thread
From: Vinod Koul @ 2026-10-03 15:25 UTC (permalink / raw)
To: Janne Grunau, Neal Gompa, Neil Armstrong, Sven Peter
Cc: asahi, linux-arm-kernel, linux-phy, linux-kernel, Paul Cristian,
stable
On Fri, 21 Aug 2026 15:50:26 +0200, Sven Peter wrote:
> This short series first fixes an oversight that prevents USB2 from
> working when DP AltMode with 4 lanes is used. Then it adds the required
> sequence to point dwc3's PIPE interface to the USB4 Native Host
> Interface which I plan to submit soon to support USB3-via-USB4 tunnels.
>
> Best,
>
> [...]
Applied, thanks!
[1/3] phy: apple: atc: Support DUMMY PIPEHANDLER state in configure_pipehandler
commit: a2fd3d1f4db720ac1deb477ce4811c5e4e60e5f8
[2/3] phy: apple: atc: Factor out the PIPE mux sequence
commit: 8ca2e111117bf1d571f7c9de5d0dd91f5b770b11
[3/3] phy: apple: atc: Implement the USB4 pipehandler state
commit: c319906aa47f8616019b01b1dd5c14eef293bb66
Best regards,
--
~Vinod
^ permalink raw reply [flat|nested] 6+ messages in thread