[PATCH v5] usb: dwc3: debugfs: Prevent any register access when devices

[PATCH v5] usb: dwc3: debugfs: Prevent any register access when devices

[Udipto Goswami]

When the dwc3 device is runtime suspended, various required clocks would
get disabled and it is not guaranteed that access to any registers would
work. Depending on the SoC glue, a register read could be as benign as
returning 0 or be fatal enough to hang the system.

In order to prevent such scenarios of fatal errors, make sure to resume
dwc3 then allow the function to proceed.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Udipto Goswami <quic_ugoswami@quicinc.com>
---
v5: Reworked the patch to resume dwc3 while accessing the registers.

 drivers/usb/dwc3/debugfs.c | 123 +++++++++++++++++++++++++++++++++++++
 1 file changed, 123 insertions(+)

diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
index e4a2560b9dc0..d622b0dfeb76 100644
--- a/drivers/usb/dwc3/debugfs.c
+++ b/drivers/usb/dwc3/debugfs.c
@@ -332,6 +332,13 @@ static int dwc3_lsp_show(struct seq_file *s, void *unused)
 	unsigned int		current_mode;
 	unsigned long		flags;
 	u32			reg;
+	int			ret;
+
+	ret = pm_runtime_get_sync(dwc->dev);
+	if (!ret || ret < 0) {
+		pm_runtime_put(dwc->dev);
+		return 0;
+	}
 
 	spin_lock_irqsave(&dwc->lock, flags);
 	reg = dwc3_readl(dwc->regs, DWC3_GSTS);
@@ -349,6 +356,7 @@ static int dwc3_lsp_show(struct seq_file *s, void *unused)
 		break;
 	}
 	spin_unlock_irqrestore(&dwc->lock, flags);
+	pm_runtime_put(dwc->dev);
 
 	return 0;
 }
@@ -395,6 +403,13 @@ static int dwc3_mode_show(struct seq_file *s, void *unused)
 	struct dwc3		*dwc = s->private;
 	unsigned long		flags;
 	u32			reg;
+	int			ret;
+
+	ret = pm_runtime_get_sync(dwc->dev);
+	if (!ret || ret < 0) {
+		pm_runtime_put(dwc->dev);
+		return 0;
+	}
 
 	spin_lock_irqsave(&dwc->lock, flags);
 	reg = dwc3_readl(dwc->regs, DWC3_GCTL);
@@ -414,6 +429,7 @@ static int dwc3_mode_show(struct seq_file *s, void *unused)
 		seq_printf(s, "UNKNOWN %08x\n", DWC3_GCTL_PRTCAP(reg));
 	}
 
+	pm_runtime_put(dwc->dev);
 	return 0;
 }
 
@@ -463,6 +479,13 @@ static int dwc3_testmode_show(struct seq_file *s, void *unused)
 	struct dwc3		*dwc = s->private;
 	unsigned long		flags;
 	u32			reg;
+	int			ret;
+
+	ret = pm_runtime_get_sync(dwc->dev);
+	if (!ret || ret < 0) {
+		pm_runtime_put(dwc->dev);
+		return 0;
+	}
 
 	spin_lock_irqsave(&dwc->lock, flags);
 	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
@@ -493,6 +516,7 @@ static int dwc3_testmode_show(struct seq_file *s, void *unused)
 		seq_printf(s, "UNKNOWN %d\n", reg);
 	}
 
+	pm_runtime_put(dwc->dev);
 	return 0;
 }
 
@@ -509,6 +533,7 @@ static ssize_t dwc3_testmode_write(struct file *file,
 	unsigned long		flags;
 	u32			testmode = 0;
 	char			buf[32];
+	int			ret;
 
 	if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
 		return -EFAULT;
@@ -526,10 +551,17 @@ static ssize_t dwc3_testmode_write(struct file *file,
 	else
 		testmode = 0;
 
+	ret = pm_runtime_get_sync(dwc->dev);
+	if (!ret || ret < 0) {
+		pm_runtime_put(dwc->dev);
+		return 0;
+	}
+
 	spin_lock_irqsave(&dwc->lock, flags);
 	dwc3_gadget_set_test_mode(dwc, testmode);
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
+	pm_runtime_put(dwc->dev);
 	return count;
 }
 
@@ -548,12 +580,20 @@ static int dwc3_link_state_show(struct seq_file *s, void *unused)
 	enum dwc3_link_state	state;
 	u32			reg;
 	u8			speed;
+	int			ret;
+
+	ret = pm_runtime_get_sync(dwc->dev);
+	if (!ret || ret < 0) {
+		pm_runtime_put(dwc->dev);
+		return 0;
+	}
 
 	spin_lock_irqsave(&dwc->lock, flags);
 	reg = dwc3_readl(dwc->regs, DWC3_GSTS);
 	if (DWC3_GSTS_CURMOD(reg) != DWC3_GSTS_CURMOD_DEVICE) {
 		seq_puts(s, "Not available\n");
 		spin_unlock_irqrestore(&dwc->lock, flags);
+		pm_runtime_put(dwc->dev);
 		return 0;
 	}
 
@@ -566,6 +606,7 @@ static int dwc3_link_state_show(struct seq_file *s, void *unused)
 		   dwc3_gadget_hs_link_string(state));
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
+	pm_runtime_put(dwc->dev);
 	return 0;
 }
 
@@ -584,6 +625,7 @@ static ssize_t dwc3_link_state_write(struct file *file,
 	char			buf[32];
 	u32			reg;
 	u8			speed;
+	int			ret;
 
 	if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
 		return -EFAULT;
@@ -603,10 +645,17 @@ static ssize_t dwc3_link_state_write(struct file *file,
 	else
 		return -EINVAL;
 
+	ret = pm_runtime_get_sync(dwc->dev);
+	if (!ret || ret < 0) {
+		pm_runtime_put(dwc->dev);
+		return 0;
+	}
+
 	spin_lock_irqsave(&dwc->lock, flags);
 	reg = dwc3_readl(dwc->regs, DWC3_GSTS);
 	if (DWC3_GSTS_CURMOD(reg) != DWC3_GSTS_CURMOD_DEVICE) {
 		spin_unlock_irqrestore(&dwc->lock, flags);
+		pm_runtime_put(dwc->dev);
 		return -EINVAL;
 	}
 
@@ -616,12 +665,14 @@ static ssize_t dwc3_link_state_write(struct file *file,
 	if (speed < DWC3_DSTS_SUPERSPEED &&
 	    state != DWC3_LINK_STATE_RECOV) {
 		spin_unlock_irqrestore(&dwc->lock, flags);
+		pm_runtime_put(dwc->dev);
 		return -EINVAL;
 	}
 
 	dwc3_gadget_set_link_state(dwc, state);
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
+	pm_runtime_put(dwc->dev);
 	return count;
 }
 
@@ -645,6 +696,13 @@ static int dwc3_tx_fifo_size_show(struct seq_file *s, void *unused)
 	unsigned long		flags;
 	u32			mdwidth;
 	u32			val;
+	int			ret;
+
+	ret = pm_runtime_get_sync(dwc->dev);
+	if (!ret || ret < 0) {
+		pm_runtime_put(dwc->dev);
+		return 0;
+	}
 
 	spin_lock_irqsave(&dwc->lock, flags);
 	val = dwc3_core_fifo_space(dep, DWC3_TXFIFO);
@@ -657,6 +715,7 @@ static int dwc3_tx_fifo_size_show(struct seq_file *s, void *unused)
 	seq_printf(s, "%u\n", val);
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
+	pm_runtime_put(dwc->dev);
 	return 0;
 }
 
@@ -667,6 +726,13 @@ static int dwc3_rx_fifo_size_show(struct seq_file *s, void *unused)
 	unsigned long		flags;
 	u32			mdwidth;
 	u32			val;
+	int			ret;
+
+	ret = pm_runtime_get_sync(dwc->dev);
+	if (!ret || ret < 0) {
+		pm_runtime_put(dwc->dev);
+		return 0;
+	}
 
 	spin_lock_irqsave(&dwc->lock, flags);
 	val = dwc3_core_fifo_space(dep, DWC3_RXFIFO);
@@ -679,6 +745,7 @@ static int dwc3_rx_fifo_size_show(struct seq_file *s, void *unused)
 	seq_printf(s, "%u\n", val);
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
+	pm_runtime_put(dwc->dev);
 	return 0;
 }
 
@@ -688,12 +755,20 @@ static int dwc3_tx_request_queue_show(struct seq_file *s, void *unused)
 	struct dwc3		*dwc = dep->dwc;
 	unsigned long		flags;
 	u32			val;
+	int			ret;
+
+	ret = pm_runtime_get_sync(dwc->dev);
+	if (!ret || ret < 0) {
+		pm_runtime_put(dwc->dev);
+		return 0;
+	}
 
 	spin_lock_irqsave(&dwc->lock, flags);
 	val = dwc3_core_fifo_space(dep, DWC3_TXREQQ);
 	seq_printf(s, "%u\n", val);
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
+	pm_runtime_put(dwc->dev);
 	return 0;
 }
 
@@ -703,12 +778,20 @@ static int dwc3_rx_request_queue_show(struct seq_file *s, void *unused)
 	struct dwc3		*dwc = dep->dwc;
 	unsigned long		flags;
 	u32			val;
+	int			ret;
+
+	ret = pm_runtime_get_sync(dwc->dev);
+	if (!ret || ret < 0) {
+		pm_runtime_put(dwc->dev);
+		return 0;
+	}
 
 	spin_lock_irqsave(&dwc->lock, flags);
 	val = dwc3_core_fifo_space(dep, DWC3_RXREQQ);
 	seq_printf(s, "%u\n", val);
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
+	pm_runtime_put(dwc->dev);
 	return 0;
 }
 
@@ -718,12 +801,20 @@ static int dwc3_rx_info_queue_show(struct seq_file *s, void *unused)
 	struct dwc3		*dwc = dep->dwc;
 	unsigned long		flags;
 	u32			val;
+	int			ret;
+
+	ret = pm_runtime_get_sync(dwc->dev);
+	if (!ret || ret < 0) {
+		pm_runtime_put(dwc->dev);
+		return 0;
+	}
 
 	spin_lock_irqsave(&dwc->lock, flags);
 	val = dwc3_core_fifo_space(dep, DWC3_RXINFOQ);
 	seq_printf(s, "%u\n", val);
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
+	pm_runtime_put(dwc->dev);
 	return 0;
 }
 
@@ -733,12 +824,20 @@ static int dwc3_descriptor_fetch_queue_show(struct seq_file *s, void *unused)
 	struct dwc3		*dwc = dep->dwc;
 	unsigned long		flags;
 	u32			val;
+	int			ret;
+
+	ret = pm_runtime_get_sync(dwc->dev);
+	if (!ret || ret < 0) {
+		pm_runtime_put(dwc->dev);
+		return 0;
+	}
 
 	spin_lock_irqsave(&dwc->lock, flags);
 	val = dwc3_core_fifo_space(dep, DWC3_DESCFETCHQ);
 	seq_printf(s, "%u\n", val);
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
+	pm_runtime_put(dwc->dev);
 	return 0;
 }
 
@@ -748,12 +847,20 @@ static int dwc3_event_queue_show(struct seq_file *s, void *unused)
 	struct dwc3		*dwc = dep->dwc;
 	unsigned long		flags;
 	u32			val;
+	int			ret;
+
+	ret = pm_runtime_get_sync(dwc->dev);
+	if (!ret || ret < 0) {
+		pm_runtime_put(dwc->dev);
+		return 0;
+	}
 
 	spin_lock_irqsave(&dwc->lock, flags);
 	val = dwc3_core_fifo_space(dep, DWC3_EVENTQ);
 	seq_printf(s, "%u\n", val);
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
+	pm_runtime_put(dwc->dev);
 	return 0;
 }
 
@@ -798,6 +905,13 @@ static int dwc3_trb_ring_show(struct seq_file *s, void *unused)
 	struct dwc3		*dwc = dep->dwc;
 	unsigned long		flags;
 	int			i;
+	int			ret;
+
+	ret = pm_runtime_get_sync(dwc->dev);
+	if (!ret || ret < 0) {
+		pm_runtime_put(dwc->dev);
+		return 0;
+	}
 
 	spin_lock_irqsave(&dwc->lock, flags);
 	if (dep->number <= 1) {
@@ -827,6 +941,7 @@ static int dwc3_trb_ring_show(struct seq_file *s, void *unused)
 out:
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
+	pm_runtime_put(dwc->dev);
 	return 0;
 }
 
@@ -839,6 +954,13 @@ static int dwc3_ep_info_register_show(struct seq_file *s, void *unused)
 	u32			lower_32_bits;
 	u32			upper_32_bits;
 	u32			reg;
+	int			ret;
+
+	ret = pm_runtime_get_sync(dwc->dev);
+	if (!ret || ret < 0) {
+		pm_runtime_put(dwc->dev);
+		return 0;
+	}
 
 	spin_lock_irqsave(&dwc->lock, flags);
 	reg = DWC3_GDBGLSPMUX_EPSELECT(dep->number);
@@ -851,6 +973,7 @@ static int dwc3_ep_info_register_show(struct seq_file *s, void *unused)
 	seq_printf(s, "0x%016llx\n", ep_info);
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
+	pm_runtime_put(dwc->dev);
 	return 0;
 }
 
-- 
2.17.1

Re: [PATCH v5] usb: dwc3: debugfs: Prevent any register access when devices

[Greg Kroah-Hartman]

On Tue, Apr 18, 2023 at 05:48:35PM +0530, Udipto Goswami wrote:
> When the dwc3 device is runtime suspended, various required clocks would
> get disabled and it is not guaranteed that access to any registers would
> work. Depending on the SoC glue, a register read could be as benign as
> returning 0 or be fatal enough to hang the system.
> 
> In order to prevent such scenarios of fatal errors, make sure to resume
> dwc3 then allow the function to proceed.
> 
> Signed-off-by: Oliver Neukum <oneukum@suse.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>

Where did they sign off on this?  I don't see that in the v4 thread, did
I miss it somewhere?

greg k-h

Re: [PATCH v5] usb: dwc3: debugfs: Prevent any register access when devices

[Johan Hovold]

On Tue, Apr 18, 2023 at 05:48:35PM +0530, Udipto Goswami wrote:

First, the subject of this patch looks wrong.

> When the dwc3 device is runtime suspended, various required clocks would
> get disabled and it is not guaranteed that access to any registers would
> work. Depending on the SoC glue, a register read could be as benign as
> returning 0 or be fatal enough to hang the system.
> 
> In order to prevent such scenarios of fatal errors, make sure to resume
> dwc3 then allow the function to proceed.
> 
> Signed-off-by: Oliver Neukum <oneukum@suse.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>

I did not sign-off on this patch (and neither did Oliver I presume).

You must never add a SoB on behalf on someone else without their
permission. Please read Documentation/process/submitting-patches.rst and
make sure you understand what SoB means before sending any further
patches.

> Signed-off-by: Udipto Goswami <quic_ugoswami@quicinc.com>
> ---
> v5: Reworked the patch to resume dwc3 while accessing the registers.

Please include the full changelog for v6 (and future patches).

>  drivers/usb/dwc3/debugfs.c | 123 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 123 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
> index e4a2560b9dc0..d622b0dfeb76 100644
> --- a/drivers/usb/dwc3/debugfs.c
> +++ b/drivers/usb/dwc3/debugfs.c
> @@ -332,6 +332,13 @@ static int dwc3_lsp_show(struct seq_file *s, void *unused)
>  	unsigned int		current_mode;
>  	unsigned long		flags;
>  	u32			reg;
> +	int			ret;
> +
> +	ret = pm_runtime_get_sync(dwc->dev);
> +	if (!ret || ret < 0) {

This is broken as you would not print anything on success (ret == 0).

Did you test this patch at all?

> +		pm_runtime_put(dwc->dev);
> +		return 0;

Why do you return 'success' on errors?

> +	}

Johan

Re: [PATCH v5] usb: dwc3: debugfs: Prevent any register access when devices

[Greg Kroah-Hartman]

On Tue, Apr 18, 2023 at 03:01:39PM +0200, Johan Hovold wrote:
> On Tue, Apr 18, 2023 at 05:48:35PM +0530, Udipto Goswami wrote:
> 
> First, the subject of this patch looks wrong.
> 
> > When the dwc3 device is runtime suspended, various required clocks would
> > get disabled and it is not guaranteed that access to any registers would
> > work. Depending on the SoC glue, a register read could be as benign as
> > returning 0 or be fatal enough to hang the system.
> > 
> > In order to prevent such scenarios of fatal errors, make sure to resume
> > dwc3 then allow the function to proceed.
> > 
> > Signed-off-by: Oliver Neukum <oneukum@suse.com>
> > Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> 
> I did not sign-off on this patch (and neither did Oliver I presume).
> 
> You must never add a SoB on behalf on someone else without their
> permission. Please read Documentation/process/submitting-patches.rst and
> make sure you understand what SoB means before sending any further
> patches.

Ah, I thought so :(

Udipto, please go complete the developer legal training that I know your
company provides for dealing with things like this as they take it very
seriously, before you resubmit this, or any other kernel patches.

thanks,

greg k-h

Re: [PATCH v5] usb: dwc3: debugfs: Prevent any register access when devices

[Udipto Goswami]

On 4/18/23 6:56 PM, Greg Kroah-Hartman wrote:
> On Tue, Apr 18, 2023 at 03:01:39PM +0200, Johan Hovold wrote:
>> On Tue, Apr 18, 2023 at 05:48:35PM +0530, Udipto Goswami wrote:
>>
>> First, the subject of this patch looks wrong.
>>
>>> When the dwc3 device is runtime suspended, various required clocks would
>>> get disabled and it is not guaranteed that access to any registers would
>>> work. Depending on the SoC glue, a register read could be as benign as
>>> returning 0 or be fatal enough to hang the system.
>>>
>>> In order to prevent such scenarios of fatal errors, make sure to resume
>>> dwc3 then allow the function to proceed.
>>>
>>> Signed-off-by: Oliver Neukum <oneukum@suse.com>
>>> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
>>
>> I did not sign-off on this patch (and neither did Oliver I presume).
>>
>> You must never add a SoB on behalf on someone else without their
>> permission. Please read Documentation/process/submitting-patches.rst and
>> make sure you understand what SoB means before sending any further
>> patches.
> 
> Ah, I thought so :(
> 
> Udipto, please go complete the developer legal training that I know your
> company provides for dealing with things like this as they take it very
> seriously, before you resubmit this, or any other kernel patches.
> 
> thanks,
> 
> greg k-h

Hi Greg, Johan, Oliver,

Apologies for this, will go through the guidelines and rework the patch
accordingly.

Re: [PATCH v5] usb: dwc3: debugfs: Prevent any register access when devices

[Udipto Goswami]

On 4/18/23 6:31 PM, Johan Hovold wrote:
> On Tue, Apr 18, 2023 at 05:48:35PM +0530, Udipto Goswami wrote:
> 
> First, the subject of this patch looks wrong.
> 
>> When the dwc3 device is runtime suspended, various required clocks would
>> get disabled and it is not guaranteed that access to any registers would
>> work. Depending on the SoC glue, a register read could be as benign as
>> returning 0 or be fatal enough to hang the system.
>>
>> In order to prevent such scenarios of fatal errors, make sure to resume
>> dwc3 then allow the function to proceed.
>>
>> Signed-off-by: Oliver Neukum <oneukum@suse.com>
>> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> 
> I did not sign-off on this patch (and neither did Oliver I presume).
> 
> You must never add a SoB on behalf on someone else without their
> permission. Please read Documentation/process/submitting-patches.rst and
> make sure you understand what SoB means before sending any further
> patches.
> 
>> Signed-off-by: Udipto Goswami <quic_ugoswami@quicinc.com>
>> ---
>> v5: Reworked the patch to resume dwc3 while accessing the registers.
> 
> Please include the full changelog for v6 (and future patches).
> 
>>   drivers/usb/dwc3/debugfs.c | 123 +++++++++++++++++++++++++++++++++++++
>>   1 file changed, 123 insertions(+)
>>
>> diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
>> index e4a2560b9dc0..d622b0dfeb76 100644
>> --- a/drivers/usb/dwc3/debugfs.c
>> +++ b/drivers/usb/dwc3/debugfs.c
>> @@ -332,6 +332,13 @@ static int dwc3_lsp_show(struct seq_file *s, void *unused)
>>   	unsigned int		current_mode;
>>   	unsigned long		flags;
>>   	u32			reg;
>> +	int			ret;
>> +
>> +	ret = pm_runtime_get_sync(dwc->dev);
>> +	if (!ret || ret < 0) {
> 
> This is broken as you would not print anything on success (ret == 0).
> 
> Did you test this patch at all?
> 
>> +		pm_runtime_put(dwc->dev);
>> +		return 0;
> 
> Why do you return 'success' on errors?
Hi Johan,

I think missed this one will fix it in v6.
> 
>> +	}
> 
> Johan

Re: [PATCH v5] usb: dwc3: debugfs: Prevent any register access when devices

[kernel test robot]

Hi Udipto,

kernel test robot noticed the following build warnings:

[auto build test WARNING on usb/usb-testing]
[also build test WARNING on usb/usb-next usb/usb-linus driver-core/driver-core-testing driver-core/driver-core-next driver-core/driver-core-linus westeri-thunderbolt/next linus/master v6.3-rc7 next-20230418]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Udipto-Goswami/usb-dwc3-debugfs-Prevent-any-register-access-when-devices/20230418-202039
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
patch link:    https://lore.kernel.org/r/20230418121835.17550-1-quic_ugoswami%40quicinc.com
patch subject: [PATCH v5] usb: dwc3: debugfs: Prevent any register access when devices
config: x86_64-randconfig-m001 (https://download.01.org/0day-ci/archive/20230419/202304191354.gk7ee6Gf-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <error27@gmail.com>
| Link: https://lore.kernel.org/r/202304191354.gk7ee6Gf-lkp@intel.com/

smatch warnings:
drivers/usb/dwc3/debugfs.c:338 dwc3_lsp_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:409 dwc3_mode_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:485 dwc3_testmode_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:555 dwc3_testmode_write() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:586 dwc3_link_state_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:649 dwc3_link_state_write() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:702 dwc3_tx_fifo_size_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:732 dwc3_rx_fifo_size_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:761 dwc3_tx_request_queue_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:784 dwc3_rx_request_queue_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:807 dwc3_rx_info_queue_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:830 dwc3_descriptor_fetch_queue_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:853 dwc3_event_queue_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:911 dwc3_trb_ring_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:960 dwc3_ep_info_register_show() warn: pm_runtime_get_sync() also returns 1 on success

vim +338 drivers/usb/dwc3/debugfs.c

62ba09d6bb6330 Thinh Nguyen              2018-11-07  329  static int dwc3_lsp_show(struct seq_file *s, void *unused)
62ba09d6bb6330 Thinh Nguyen              2018-11-07  330  {
62ba09d6bb6330 Thinh Nguyen              2018-11-07  331  	struct dwc3		*dwc = s->private;
62ba09d6bb6330 Thinh Nguyen              2018-11-07  332  	unsigned int		current_mode;
62ba09d6bb6330 Thinh Nguyen              2018-11-07  333  	unsigned long		flags;
62ba09d6bb6330 Thinh Nguyen              2018-11-07  334  	u32			reg;
86f75fd9ae2609 Udipto Goswami            2023-04-18  335  	int			ret;
86f75fd9ae2609 Udipto Goswami            2023-04-18  336  
86f75fd9ae2609 Udipto Goswami            2023-04-18  337  	ret = pm_runtime_get_sync(dwc->dev);
86f75fd9ae2609 Udipto Goswami            2023-04-18 @338  	if (!ret || ret < 0) {
86f75fd9ae2609 Udipto Goswami            2023-04-18  339  		pm_runtime_put(dwc->dev);
86f75fd9ae2609 Udipto Goswami            2023-04-18  340  		return 0;

I don't know what's going on here, but Smatch doesn't like it.  :P

86f75fd9ae2609 Udipto Goswami            2023-04-18  341  	}
62ba09d6bb6330 Thinh Nguyen              2018-11-07  342  
62ba09d6bb6330 Thinh Nguyen              2018-11-07  343  	spin_lock_irqsave(&dwc->lock, flags);
62ba09d6bb6330 Thinh Nguyen              2018-11-07  344  	reg = dwc3_readl(dwc->regs, DWC3_GSTS);
62ba09d6bb6330 Thinh Nguyen              2018-11-07  345  	current_mode = DWC3_GSTS_CURMOD(reg);
62ba09d6bb6330 Thinh Nguyen              2018-11-07  346  
62ba09d6bb6330 Thinh Nguyen              2018-11-07  347  	switch (current_mode) {
62ba09d6bb6330 Thinh Nguyen              2018-11-07  348  	case DWC3_GSTS_CURMOD_HOST:
62ba09d6bb6330 Thinh Nguyen              2018-11-07  349  		dwc3_host_lsp(s);
62ba09d6bb6330 Thinh Nguyen              2018-11-07  350  		break;
62ba09d6bb6330 Thinh Nguyen              2018-11-07  351  	case DWC3_GSTS_CURMOD_DEVICE:
62ba09d6bb6330 Thinh Nguyen              2018-11-07  352  		dwc3_gadget_lsp(s);
62ba09d6bb6330 Thinh Nguyen              2018-11-07  353  		break;
62ba09d6bb6330 Thinh Nguyen              2018-11-07  354  	default:
62ba09d6bb6330 Thinh Nguyen              2018-11-07  355  		seq_puts(s, "Mode is unknown, no LSP register printed\n");
62ba09d6bb6330 Thinh Nguyen              2018-11-07  356  		break;
62ba09d6bb6330 Thinh Nguyen              2018-11-07  357  	}
62ba09d6bb6330 Thinh Nguyen              2018-11-07  358  	spin_unlock_irqrestore(&dwc->lock, flags);
86f75fd9ae2609 Udipto Goswami            2023-04-18  359  	pm_runtime_put(dwc->dev);
62ba09d6bb6330 Thinh Nguyen              2018-11-07  360  
62ba09d6bb6330 Thinh Nguyen              2018-11-07  361  	return 0;
62ba09d6bb6330 Thinh Nguyen              2018-11-07  362  }

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests