[PATCH AUTOSEL 6.4 12/25] usb: cdns3: Put the cdns set active part outside the spin lock

[PATCH AUTOSEL 6.4 12/25] usb: cdns3: Put the cdns set active part outside the spin lock

[Sasha Levin]

From: Xiaolei Wang <xiaolei.wang@windriver.com>

[ Upstream commit 2319b9c87fe243327285f2fefd7374ffd75a65fc ]

The device may be scheduled during the resume process,
so this cannot appear in atomic operations. Since
pm_runtime_set_active will resume suppliers, put set
active outside the spin lock, which is only used to
protect the struct cdns data structure, otherwise the
kernel will report the following warning:

  BUG: sleeping function called from invalid context at drivers/base/power/runtime.c:1163
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 651, name: sh
  preempt_count: 1, expected: 0
  RCU nest depth: 0, expected: 0
  CPU: 0 PID: 651 Comm: sh Tainted: G        WC         6.1.20 #1
  Hardware name: Freescale i.MX8QM MEK (DT)
  Call trace:
    dump_backtrace.part.0+0xe0/0xf0
    show_stack+0x18/0x30
    dump_stack_lvl+0x64/0x80
    dump_stack+0x1c/0x38
    __might_resched+0x1fc/0x240
    __might_sleep+0x68/0xc0
    __pm_runtime_resume+0x9c/0xe0
    rpm_get_suppliers+0x68/0x1b0
    __pm_runtime_set_status+0x298/0x560
    cdns_resume+0xb0/0x1c0
    cdns3_controller_resume.isra.0+0x1e0/0x250
    cdns3_plat_resume+0x28/0x40

Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
Acked-by: Peter Chen <peter.chen@kernel.org>
Link: https://lore.kernel.org/r/20230616021952.1025854-1-xiaolei.wang@windriver.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/cdns3/cdns3-plat.c |  3 ++-
 drivers/usb/cdns3/cdnsp-pci.c  |  3 ++-
 drivers/usb/cdns3/core.c       | 15 +++++++++++----
 drivers/usb/cdns3/core.h       |  7 +++++--
 4 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/cdns3/cdns3-plat.c b/drivers/usb/cdns3/cdns3-plat.c
index 2bc5d094548b6..726b2e4f67e4d 100644
--- a/drivers/usb/cdns3/cdns3-plat.c
+++ b/drivers/usb/cdns3/cdns3-plat.c
@@ -256,9 +256,10 @@ static int cdns3_controller_resume(struct device *dev, pm_message_t msg)
 	cdns3_set_platform_suspend(cdns->dev, false, false);
 
 	spin_lock_irqsave(&cdns->lock, flags);
-	cdns_resume(cdns, !PMSG_IS_AUTO(msg));
+	cdns_resume(cdns);
 	cdns->in_lpm = false;
 	spin_unlock_irqrestore(&cdns->lock, flags);
+	cdns_set_active(cdns, !PMSG_IS_AUTO(msg));
 	if (cdns->wakeup_pending) {
 		cdns->wakeup_pending = false;
 		enable_irq(cdns->wakeup_irq);
diff --git a/drivers/usb/cdns3/cdnsp-pci.c b/drivers/usb/cdns3/cdnsp-pci.c
index 7b151f5af3ccb..0725668ffea4c 100644
--- a/drivers/usb/cdns3/cdnsp-pci.c
+++ b/drivers/usb/cdns3/cdnsp-pci.c
@@ -208,8 +208,9 @@ static int __maybe_unused cdnsp_pci_resume(struct device *dev)
 	int ret;
 
 	spin_lock_irqsave(&cdns->lock, flags);
-	ret = cdns_resume(cdns, 1);
+	ret = cdns_resume(cdns);
 	spin_unlock_irqrestore(&cdns->lock, flags);
+	cdns_set_active(cdns, 1);
 
 	return ret;
 }
diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c
index dbcdf3b24b477..7b20d2d5c262e 100644
--- a/drivers/usb/cdns3/core.c
+++ b/drivers/usb/cdns3/core.c
@@ -522,9 +522,8 @@ int cdns_suspend(struct cdns *cdns)
 }
 EXPORT_SYMBOL_GPL(cdns_suspend);
 
-int cdns_resume(struct cdns *cdns, u8 set_active)
+int cdns_resume(struct cdns *cdns)
 {
-	struct device *dev = cdns->dev;
 	enum usb_role real_role;
 	bool role_changed = false;
 	int ret = 0;
@@ -556,15 +555,23 @@ int cdns_resume(struct cdns *cdns, u8 set_active)
 	if (cdns->roles[cdns->role]->resume)
 		cdns->roles[cdns->role]->resume(cdns, cdns_power_is_lost(cdns));
 
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cdns_resume);
+
+void cdns_set_active(struct cdns *cdns, u8 set_active)
+{
+	struct device *dev = cdns->dev;
+
 	if (set_active) {
 		pm_runtime_disable(dev);
 		pm_runtime_set_active(dev);
 		pm_runtime_enable(dev);
 	}
 
-	return 0;
+	return;
 }
-EXPORT_SYMBOL_GPL(cdns_resume);
+EXPORT_SYMBOL_GPL(cdns_set_active);
 #endif /* CONFIG_PM_SLEEP */
 
 MODULE_AUTHOR("Peter Chen <peter.chen@nxp.com>");
diff --git a/drivers/usb/cdns3/core.h b/drivers/usb/cdns3/core.h
index 2d332a788871e..4a4dbc2c15615 100644
--- a/drivers/usb/cdns3/core.h
+++ b/drivers/usb/cdns3/core.h
@@ -125,10 +125,13 @@ int cdns_init(struct cdns *cdns);
 int cdns_remove(struct cdns *cdns);
 
 #ifdef CONFIG_PM_SLEEP
-int cdns_resume(struct cdns *cdns, u8 set_active);
+int cdns_resume(struct cdns *cdns);
 int cdns_suspend(struct cdns *cdns);
+void cdns_set_active(struct cdns *cdns, u8 set_active);
 #else /* CONFIG_PM_SLEEP */
-static inline int cdns_resume(struct cdns *cdns, u8 set_active)
+static inline int cdns_resume(struct cdns *cdns)
+{ return 0; }
+static inline int cdns_set_active(struct cdns *cdns, u8 set_active)
 { return 0; }
 static inline int cdns_suspend(struct cdns *cdns)
 { return 0; }
-- 
2.40.1

[PATCH AUTOSEL 6.4 13/25] usb: gadget: fsl_qe_udc: validate endpoint index for ch9 udc

[Sasha Levin]

From: Ma Ke <make_ruc2021@163.com>

[ Upstream commit ce9daa2efc0872a9a68ea51dc8000df05893ef2e ]

We should verify the bound of the array to assure that host
may not manipulate the index to point past endpoint array.

Signed-off-by: Ma Ke <make_ruc2021@163.com>
Acked-by: Li Yang <leoyang.li@nxp.com>
Link: https://lore.kernel.org/r/20230628081511.186850-1-make_ruc2021@163.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/gadget/udc/fsl_qe_udc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/gadget/udc/fsl_qe_udc.c b/drivers/usb/gadget/udc/fsl_qe_udc.c
index 3b1cc8fa30c83..f4e5cbd193b7b 100644
--- a/drivers/usb/gadget/udc/fsl_qe_udc.c
+++ b/drivers/usb/gadget/udc/fsl_qe_udc.c
@@ -1959,6 +1959,8 @@ static void ch9getstatus(struct qe_udc *udc, u8 request_type, u16 value,
 	} else if ((request_type & USB_RECIP_MASK) == USB_RECIP_ENDPOINT) {
 		/* Get endpoint status */
 		int pipe = index & USB_ENDPOINT_NUMBER_MASK;
+		if (pipe >= USB_MAX_ENDPOINTS)
+			goto stall;
 		struct qe_ep *target_ep = &udc->eps[pipe];
 		u16 usep;
 
-- 
2.40.1

[PATCH AUTOSEL 6.4 19/25] usb: ehci: add workaround for chipidea PORTSC.PEC bug

[Sasha Levin]

From: Xu Yang <xu.yang_2@nxp.com>

[ Upstream commit dda4b60ed70bd670eefda081f70c0cb20bbeb1fa ]

Some NXP processor using chipidea IP has a bug when frame babble is
detected.

As per 4.15.1.1.1 Serial Bus Babble:
  A babble condition also exists if IN transaction is in progress at
High-speed SOF2 point. This is called frame babble. The host controller
must disable the port to which the frame babble is detected.

The USB controller has disabled the port (PE cleared) and has asserted
USBERRINT when frame babble is detected, but PEC is not asserted.
Therefore, the SW isn't aware that port has been disabled. Then the
SW keeps sending packets to this port, but all of the transfers will
fail.

This workaround will firstly assert PCD by SW when USBERRINT is detected
and then judge whether port change has really occurred or not by polling
roothub status. Because the PEC doesn't get asserted in our case, this
patch will also assert it by SW when specific conditions are satisfied.

Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Acked-by: Peter Chen <peter.chen@kernel.org>
Link: https://lore.kernel.org/r/20230809024432.535160-1-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/host/ehci-hcd.c |  8 ++++++--
 drivers/usb/host/ehci-hub.c | 10 +++++++++-
 drivers/usb/host/ehci.h     | 10 ++++++++++
 3 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index a1930db0da1c3..802bfafb1012b 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -755,10 +755,14 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
 
 	/* normal [4.15.1.2] or error [4.15.1.1] completion */
 	if (likely ((status & (STS_INT|STS_ERR)) != 0)) {
-		if (likely ((status & STS_ERR) == 0))
+		if (likely ((status & STS_ERR) == 0)) {
 			INCR(ehci->stats.normal);
-		else
+		} else {
+			/* Force to check port status */
+			if (ehci->has_ci_pec_bug)
+				status |= STS_PCD;
 			INCR(ehci->stats.error);
+		}
 		bh = 1;
 	}
 
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index efe30e3be22f7..1aee392e84927 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -674,7 +674,8 @@ ehci_hub_status_data (struct usb_hcd *hcd, char *buf)
 
 		if ((temp & mask) != 0 || test_bit(i, &ehci->port_c_suspend)
 				|| (ehci->reset_done[i] && time_after_eq(
-					jiffies, ehci->reset_done[i]))) {
+					jiffies, ehci->reset_done[i]))
+				|| ehci_has_ci_pec_bug(ehci, temp)) {
 			if (i < 7)
 			    buf [0] |= 1 << (i + 1);
 			else
@@ -875,6 +876,13 @@ int ehci_hub_control(
 		if (temp & PORT_PEC)
 			status |= USB_PORT_STAT_C_ENABLE << 16;
 
+		if (ehci_has_ci_pec_bug(ehci, temp)) {
+			status |= USB_PORT_STAT_C_ENABLE << 16;
+			ehci_info(ehci,
+				"PE is cleared by HW port:%d PORTSC:%08x\n",
+				wIndex + 1, temp);
+		}
+
 		if ((temp & PORT_OCC) && (!ignore_oc && !ehci->spurious_oc)){
 			status |= USB_PORT_STAT_C_OVERCURRENT << 16;
 
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index c5c7f87825493..1441e34007961 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -207,6 +207,7 @@ struct ehci_hcd {			/* one per controller */
 	unsigned		has_fsl_port_bug:1; /* FreeScale */
 	unsigned		has_fsl_hs_errata:1;	/* Freescale HS quirk */
 	unsigned		has_fsl_susp_errata:1;	/* NXP SUSP quirk */
+	unsigned		has_ci_pec_bug:1;	/* ChipIdea PEC bug */
 	unsigned		big_endian_mmio:1;
 	unsigned		big_endian_desc:1;
 	unsigned		big_endian_capbase:1;
@@ -707,6 +708,15 @@ ehci_port_speed(struct ehci_hcd *ehci, unsigned int portsc)
  */
 #define ehci_has_fsl_susp_errata(e)	((e)->has_fsl_susp_errata)
 
+/*
+ * Some Freescale/NXP processors using ChipIdea IP have a bug in which
+ * disabling the port (PE is cleared) does not cause PEC to be asserted
+ * when frame babble is detected.
+ */
+#define ehci_has_ci_pec_bug(e, portsc) \
+	((e)->has_ci_pec_bug && ((e)->command & CMD_PSE) \
+	 && !(portsc & PORT_PEC) && !(portsc & PORT_PE))
+
 /*
  * While most USB host controllers implement their registers in
  * little-endian format, a minority (celleb companion chip) implement
-- 
2.40.1

[PATCH AUTOSEL 6.4 20/25] usb: chipidea: add workaround for chipidea PEC bug

[Sasha Levin]

From: Xu Yang <xu.yang_2@nxp.com>

[ Upstream commit 12e6ac69cc7e7d3367599ae26a92a0f9a18bc728 ]

Some NXP processors using ChipIdea USB IP have a bug when frame babble is
detected.

Issue description:
In USB camera test, our controller is host in HS mode. In ISOC IN, when
device sends data across the micro frame, it causes the babble in host
controller. This will clear the PE bit. In spec, it also requires to set
the PEC bit and then set the PCI bit. Without the PCI interrupt, the
software does not know the PE is cleared.

This will add a flag CI_HDRC_HAS_PORTSC_PEC_MISSED to some impacted
platform datas. And the ehci host driver will assert PEC by SW when
specific conditions are satisfied.

Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20230809024432.535160-2-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/chipidea/ci.h          | 1 +
 drivers/usb/chipidea/ci_hdrc_imx.c | 4 +++-
 drivers/usb/chipidea/core.c        | 2 ++
 drivers/usb/chipidea/host.c        | 1 +
 include/linux/usb/chipidea.h       | 1 +
 5 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/chipidea/ci.h b/drivers/usb/chipidea/ci.h
index f210b7489fd5b..78cfbe621272c 100644
--- a/drivers/usb/chipidea/ci.h
+++ b/drivers/usb/chipidea/ci.h
@@ -257,6 +257,7 @@ struct ci_hdrc {
 	bool				id_event;
 	bool				b_sess_valid_event;
 	bool				imx28_write_fix;
+	bool				has_portsc_pec_bug;
 	bool				supports_runtime_pm;
 	bool				in_lpm;
 	bool				wakeup_int;
diff --git a/drivers/usb/chipidea/ci_hdrc_imx.c b/drivers/usb/chipidea/ci_hdrc_imx.c
index f7577f2bd2c5d..4a5a4904aab6d 100644
--- a/drivers/usb/chipidea/ci_hdrc_imx.c
+++ b/drivers/usb/chipidea/ci_hdrc_imx.c
@@ -67,11 +67,13 @@ static const struct ci_hdrc_imx_platform_flag imx7d_usb_data = {
 
 static const struct ci_hdrc_imx_platform_flag imx7ulp_usb_data = {
 	.flags = CI_HDRC_SUPPORTS_RUNTIME_PM |
+		CI_HDRC_HAS_PORTSC_PEC_MISSED |
 		CI_HDRC_PMQOS,
 };
 
 static const struct ci_hdrc_imx_platform_flag imx8ulp_usb_data = {
-	.flags = CI_HDRC_SUPPORTS_RUNTIME_PM,
+	.flags = CI_HDRC_SUPPORTS_RUNTIME_PM |
+		CI_HDRC_HAS_PORTSC_PEC_MISSED,
 };
 
 static const struct of_device_id ci_hdrc_imx_dt_ids[] = {
diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
index 798cb077867ab..449ec7d3f0027 100644
--- a/drivers/usb/chipidea/core.c
+++ b/drivers/usb/chipidea/core.c
@@ -1045,6 +1045,8 @@ static int ci_hdrc_probe(struct platform_device *pdev)
 		CI_HDRC_IMX28_WRITE_FIX);
 	ci->supports_runtime_pm = !!(ci->platdata->flags &
 		CI_HDRC_SUPPORTS_RUNTIME_PM);
+	ci->has_portsc_pec_bug = !!(ci->platdata->flags &
+		CI_HDRC_HAS_PORTSC_PEC_MISSED);
 	platform_set_drvdata(pdev, ci);
 
 	ret = hw_device_init(ci, base);
diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c
index ebe7400243b12..08af26b762a2d 100644
--- a/drivers/usb/chipidea/host.c
+++ b/drivers/usb/chipidea/host.c
@@ -151,6 +151,7 @@ static int host_start(struct ci_hdrc *ci)
 	ehci->has_hostpc = ci->hw_bank.lpm;
 	ehci->has_tdi_phy_lpm = ci->hw_bank.lpm;
 	ehci->imx28_write_fix = ci->imx28_write_fix;
+	ehci->has_ci_pec_bug = ci->has_portsc_pec_bug;
 
 	priv = (struct ehci_ci_priv *)ehci->priv;
 	priv->reg_vbus = NULL;
diff --git a/include/linux/usb/chipidea.h b/include/linux/usb/chipidea.h
index ee38835ed77cc..0b4f2d5faa080 100644
--- a/include/linux/usb/chipidea.h
+++ b/include/linux/usb/chipidea.h
@@ -63,6 +63,7 @@ struct ci_hdrc_platform_data {
 #define CI_HDRC_IMX_IS_HSIC		BIT(14)
 #define CI_HDRC_PMQOS			BIT(15)
 #define CI_HDRC_PHY_VBUS_CONTROL	BIT(16)
+#define CI_HDRC_HAS_PORTSC_PEC_MISSED	BIT(17)
 	enum usb_dr_mode	dr_mode;
 #define CI_HDRC_CONTROLLER_RESET_EVENT		0
 #define CI_HDRC_CONTROLLER_STOPPED_EVENT	1
-- 
2.40.1

[PATCH AUTOSEL 6.4 24/25] usb: cdc-acm: move ldisc dcd notification outside of acm's read lock

[Sasha Levin]

From: Dan Drown <dan-netdev@drown.org>

[ Upstream commit f72ae60881ff685004d7de7152517607fcd9968f ]

dcd_change notification call moved outside of the acm->read_lock
to protect any future tty ldisc that calls wait_serial_change()

Signed-off-by: Dan Drown <dan-netdev@drown.org>
Acked-by: Oliver Neukum <oneukum@suse.com>
Link: https://lore.kernel.org/r/ZN1zV/zjPgpGlHXo@vps3.drown.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/class/cdc-acm.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 11da5fb284d0a..ca51230f44409 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -318,6 +318,16 @@ static void acm_process_notification(struct acm *acm, unsigned char *buf)
 		}
 
 		difference = acm->ctrlin ^ newctrl;
+
+		if ((difference & USB_CDC_SERIAL_STATE_DCD) && acm->port.tty) {
+			struct tty_ldisc *ld = tty_ldisc_ref(acm->port.tty);
+			if (ld) {
+				if (ld->ops->dcd_change)
+					ld->ops->dcd_change(acm->port.tty, newctrl & USB_CDC_SERIAL_STATE_DCD);
+				tty_ldisc_deref(ld);
+			}
+		}
+
 		spin_lock_irqsave(&acm->read_lock, flags);
 		acm->ctrlin = newctrl;
 		acm->oldcount = acm->iocount;
-- 
2.40.1

Re: [PATCH AUTOSEL 6.4 24/25] usb: cdc-acm: move ldisc dcd notification outside of acm's read lock

[Johan Hovold]

On Fri, Sep 08, 2023 at 08:37:12PM -0400, Sasha Levin wrote:
> From: Dan Drown <dan-netdev@drown.org>
> 
> [ Upstream commit f72ae60881ff685004d7de7152517607fcd9968f ]
> 
> dcd_change notification call moved outside of the acm->read_lock
> to protect any future tty ldisc that calls wait_serial_change()
> 
> Signed-off-by: Dan Drown <dan-netdev@drown.org>
> Acked-by: Oliver Neukum <oneukum@suse.com>
> Link: https://lore.kernel.org/r/ZN1zV/zjPgpGlHXo@vps3.drown.org
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
>  drivers/usb/class/cdc-acm.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
> index 11da5fb284d0a..ca51230f44409 100644
> --- a/drivers/usb/class/cdc-acm.c
> +++ b/drivers/usb/class/cdc-acm.c
> @@ -318,6 +318,16 @@ static void acm_process_notification(struct acm *acm, unsigned char *buf)
>  		}
>  
>  		difference = acm->ctrlin ^ newctrl;
> +
> +		if ((difference & USB_CDC_SERIAL_STATE_DCD) && acm->port.tty) {
> +			struct tty_ldisc *ld = tty_ldisc_ref(acm->port.tty);
> +			if (ld) {
> +				if (ld->ops->dcd_change)
> +					ld->ops->dcd_change(acm->port.tty, newctrl & USB_CDC_SERIAL_STATE_DCD);
> +				tty_ldisc_deref(ld);
> +			}
> +		}
> +
>  		spin_lock_irqsave(&acm->read_lock, flags);
>  		acm->ctrlin = newctrl;
>  		acm->oldcount = acm->iocount;

This is a fix for a commit in 6.6-rc1 (3b563b901eef ("usb: cdc-acm: add
PPS support")) so a backport of it makes no sense.

Please drop.

Johan

Re: [PATCH AUTOSEL 6.4 24/25] usb: cdc-acm: move ldisc dcd notification outside of acm's read lock

[Sasha Levin]

On Mon, Sep 11, 2023 at 11:19:13AM +0200, Johan Hovold wrote:
>On Fri, Sep 08, 2023 at 08:37:12PM -0400, Sasha Levin wrote:
>> From: Dan Drown <dan-netdev@drown.org>
>>
>> [ Upstream commit f72ae60881ff685004d7de7152517607fcd9968f ]
>>
>> dcd_change notification call moved outside of the acm->read_lock
>> to protect any future tty ldisc that calls wait_serial_change()
>>
>> Signed-off-by: Dan Drown <dan-netdev@drown.org>
>> Acked-by: Oliver Neukum <oneukum@suse.com>
>> Link: https://lore.kernel.org/r/ZN1zV/zjPgpGlHXo@vps3.drown.org
>> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>> Signed-off-by: Sasha Levin <sashal@kernel.org>
>> ---
>>  drivers/usb/class/cdc-acm.c | 10 ++++++++++
>>  1 file changed, 10 insertions(+)
>>
>> diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
>> index 11da5fb284d0a..ca51230f44409 100644
>> --- a/drivers/usb/class/cdc-acm.c
>> +++ b/drivers/usb/class/cdc-acm.c
>> @@ -318,6 +318,16 @@ static void acm_process_notification(struct acm *acm, unsigned char *buf)
>>  		}
>>
>>  		difference = acm->ctrlin ^ newctrl;
>> +
>> +		if ((difference & USB_CDC_SERIAL_STATE_DCD) && acm->port.tty) {
>> +			struct tty_ldisc *ld = tty_ldisc_ref(acm->port.tty);
>> +			if (ld) {
>> +				if (ld->ops->dcd_change)
>> +					ld->ops->dcd_change(acm->port.tty, newctrl & USB_CDC_SERIAL_STATE_DCD);
>> +				tty_ldisc_deref(ld);
>> +			}
>> +		}
>> +
>>  		spin_lock_irqsave(&acm->read_lock, flags);
>>  		acm->ctrlin = newctrl;
>>  		acm->oldcount = acm->iocount;
>
>This is a fix for a commit in 6.6-rc1 (3b563b901eef ("usb: cdc-acm: add
>PPS support")) so a backport of it makes no sense.
>
>Please drop.

Done, thanks!

-- 
Thanks,
Sasha