diff mbox series

[v3] usbip: Don't submit special requests twice

Message ID 20231130231650.22410-1-simon@holesch.de (mailing list archive)
State Superseded
Headers show
Series [v3] usbip: Don't submit special requests twice | expand

Commit Message

Simon Holesch Nov. 30, 2023, 11:10 p.m. UTC 
Skip submitting URBs, when identical requests were already sent in
tweak_special_requests(). Instead call the completion handler directly
to return the result of the URB.

Even though submitting those requests twice should be harmless, there
are USB devices that react poorly to some duplicated requests.

One example is the ChipIdea controller implementation in U-Boot: The
second SET_CONFIURATION request makes U-Boot disable and re-enable all
endpoints. Re-enabling an endpoint in the ChipIdea controller, however,
was broken until U-Boot commit b272c8792502 ("usb: ci: Fix gadget
reinit").

Signed-off-by: Simon Holesch <simon@holesch.de>
---

Changes in v3:
- handle errors in tweak_* routines: send URB if tweaking fails

Changes in v2:
- explain change in commit message

Thanks again for the feedback!

 drivers/usb/usbip/stub_rx.c | 73 +++++++++++++++++++++++--------------
 1 file changed, 46 insertions(+), 27 deletions(-)

Comments

Shuah Khan Dec. 4, 2023, 6:19 p.m. UTC | #1 
On 11/30/23 16:10, Simon Holesch wrote:
> Skip submitting URBs, when identical requests were already sent in
> tweak_special_requests(). Instead call the completion handler directly
> to return the result of the URB.
> 
> Even though submitting those requests twice should be harmless, there
> are USB devices that react poorly to some duplicated requests.
> 
> One example is the ChipIdea controller implementation in U-Boot: The
> second SET_CONFIURATION request makes U-Boot disable and re-enable all
> endpoints. Re-enabling an endpoint in the ChipIdea controller, however,
> was broken until U-Boot commit b272c8792502 ("usb: ci: Fix gadget
> reinit").
> 
> Signed-off-by: Simon Holesch <simon@holesch.de>
> ---
> 
> Changes in v3:
> - handle errors in tweak_* routines: send URB if tweaking fails
> 
> Changes in v2:
> - explain change in commit message
> 
> Thanks again for the feedback!

Looks good to me.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>

thanks,
-- Shuah
Greg Kroah-Hartman Dec. 6, 2023, 3:38 a.m. UTC | #2 
On Fri, Dec 01, 2023 at 12:10:13AM +0100, Simon Holesch wrote:
> Skip submitting URBs, when identical requests were already sent in
> tweak_special_requests(). Instead call the completion handler directly
> to return the result of the URB.
> 
> Even though submitting those requests twice should be harmless, there
> are USB devices that react poorly to some duplicated requests.
> 
> One example is the ChipIdea controller implementation in U-Boot: The
> second SET_CONFIURATION request makes U-Boot disable and re-enable all
> endpoints. Re-enabling an endpoint in the ChipIdea controller, however,
> was broken until U-Boot commit b272c8792502 ("usb: ci: Fix gadget
> reinit").
> 
> Signed-off-by: Simon Holesch <simon@holesch.de>
> ---
> 
> Changes in v3:
> - handle errors in tweak_* routines: send URB if tweaking fails
> 
> Changes in v2:
> - explain change in commit message
> 
> Thanks again for the feedback!
> 
>  drivers/usb/usbip/stub_rx.c | 73 +++++++++++++++++++++++--------------
>  1 file changed, 46 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/usb/usbip/stub_rx.c b/drivers/usb/usbip/stub_rx.c
> index fc01b31bbb87..76a6f46b8676 100644
> --- a/drivers/usb/usbip/stub_rx.c
> +++ b/drivers/usb/usbip/stub_rx.c
> @@ -144,53 +144,62 @@ static int tweak_set_configuration_cmd(struct urb *urb)
>  	if (err && err != -ENODEV)
>  		dev_err(&sdev->udev->dev, "can't set config #%d, error %d\n",
>  			config, err);
> -	return 0;
> +	return err;
>  }
>  
>  static int tweak_reset_device_cmd(struct urb *urb)
>  {
>  	struct stub_priv *priv = (struct stub_priv *) urb->context;
>  	struct stub_device *sdev = priv->sdev;
> +	int err;
>  
>  	dev_info(&urb->dev->dev, "usb_queue_reset_device\n");
>  
> -	if (usb_lock_device_for_reset(sdev->udev, NULL) < 0) {
> +	err = usb_lock_device_for_reset(sdev->udev, NULL)

You didn't actually build this change, so how was it tested?

{sigh}

greg k-h
Simon Holesch Dec. 6, 2023, 4:57 a.m. UTC | #3 
On Wed Dec 6, 2023 at 4:38 AM CET, Greg Kroah-Hartman wrote:
> On Fri, Dec 01, 2023 at 12:10:13AM +0100, Simon Holesch wrote:
> > -	if (usb_lock_device_for_reset(sdev->udev, NULL) < 0) {
> > +	err = usb_lock_device_for_reset(sdev->udev, NULL)
>
> You didn't actually build this change, so how was it tested?

Last thing I did was update the comment of tweak_special_requests().
Must have hit undo once too often, because I've seen (and fixed) this
error. Really sorry about that. I'll send a v4 with a detailed test
description.

Simon

> {sigh}
>
> greg k-h
kernel test robot Dec. 6, 2023, 7 a.m. UTC | #4 
Hi Simon,

kernel test robot noticed the following build errors:

[auto build test ERROR on usb/usb-testing]
[also build test ERROR on usb/usb-next usb/usb-linus linus/master v6.7-rc4 next-20231206]
[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/Simon-Holesch/usbip-Don-t-submit-special-requests-twice/20231201-072027
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
patch link:    https://lore.kernel.org/r/20231130231650.22410-1-simon%40holesch.de
patch subject: [PATCH v3] usbip: Don't submit special requests twice
config: hexagon-randconfig-r081-20231201 (https://download.01.org/0day-ci/archive/20231206/202312061416.KFbIrElk-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231206/202312061416.KFbIrElk-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202312061416.KFbIrElk-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from drivers/usb/usbip/stub_rx.c:8:
   In file included from include/linux/usb.h:16:
   In file included from include/linux/interrupt.h:11:
   In file included from include/linux/hardirq.h:11:
   In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
   In file included from include/asm-generic/hardirq.h:17:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/hexagon/include/asm/io.h:337:
   include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     547 |         val = __raw_readb(PCI_IOBASE + addr);
         |                           ~~~~~~~~~~ ^
   include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     560 |         val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
         |                                                         ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu'
      37 | #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
         |                                                   ^
   In file included from drivers/usb/usbip/stub_rx.c:8:
   In file included from include/linux/usb.h:16:
   In file included from include/linux/interrupt.h:11:
   In file included from include/linux/hardirq.h:11:
   In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
   In file included from include/asm-generic/hardirq.h:17:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/hexagon/include/asm/io.h:337:
   include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     573 |         val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
         |                                                         ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu'
      35 | #define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
         |                                                   ^
   In file included from drivers/usb/usbip/stub_rx.c:8:
   In file included from include/linux/usb.h:16:
   In file included from include/linux/interrupt.h:11:
   In file included from include/linux/hardirq.h:11:
   In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
   In file included from include/asm-generic/hardirq.h:17:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/hexagon/include/asm/io.h:337:
   include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     584 |         __raw_writeb(value, PCI_IOBASE + addr);
         |                             ~~~~~~~~~~ ^
   include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     594 |         __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
         |                                                       ~~~~~~~~~~ ^
   include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     604 |         __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
         |                                                       ~~~~~~~~~~ ^
>> drivers/usb/usbip/stub_rx.c:158:51: error: expected ';' after expression
     158 |         err = usb_lock_device_for_reset(sdev->udev, NULL)
         |                                                          ^
         |                                                          ;
   6 warnings and 1 error generated.


vim +158 drivers/usb/usbip/stub_rx.c

   149	
   150	static int tweak_reset_device_cmd(struct urb *urb)
   151	{
   152		struct stub_priv *priv = (struct stub_priv *) urb->context;
   153		struct stub_device *sdev = priv->sdev;
   154		int err;
   155	
   156		dev_info(&urb->dev->dev, "usb_queue_reset_device\n");
   157	
 > 158		err = usb_lock_device_for_reset(sdev->udev, NULL)
   159		if (err < 0) {
   160			dev_err(&urb->dev->dev, "could not obtain lock to reset device\n");
   161			return err;
   162		}
   163		err = usb_reset_device(sdev->udev);
   164		usb_unlock_device(sdev->udev);
   165	
   166		return err;
   167	}
   168
diff mbox series

Patch

diff --git a/drivers/usb/usbip/stub_rx.c b/drivers/usb/usbip/stub_rx.c
index fc01b31bbb87..76a6f46b8676 100644
--- a/drivers/usb/usbip/stub_rx.c
+++ b/drivers/usb/usbip/stub_rx.c
@@ -144,53 +144,62 @@  static int tweak_set_configuration_cmd(struct urb *urb)
 	if (err && err != -ENODEV)
 		dev_err(&sdev->udev->dev, "can't set config #%d, error %d\n",
 			config, err);
-	return 0;
+	return err;
 }
 
 static int tweak_reset_device_cmd(struct urb *urb)
 {
 	struct stub_priv *priv = (struct stub_priv *) urb->context;
 	struct stub_device *sdev = priv->sdev;
+	int err;
 
 	dev_info(&urb->dev->dev, "usb_queue_reset_device\n");
 
-	if (usb_lock_device_for_reset(sdev->udev, NULL) < 0) {
+	err = usb_lock_device_for_reset(sdev->udev, NULL)
+	if (err < 0) {
 		dev_err(&urb->dev->dev, "could not obtain lock to reset device\n");
-		return 0;
+		return err;
 	}
-	usb_reset_device(sdev->udev);
+	err = usb_reset_device(sdev->udev);
 	usb_unlock_device(sdev->udev);
 
-	return 0;
+	return err;
 }
 
 /*
  * clear_halt, set_interface, and set_configuration require special tricks.
+ * Returns 1 if request was tweaked, 0 otherwise.
  */
-static void tweak_special_requests(struct urb *urb)
+static int tweak_special_requests(struct urb *urb)
 {
+	int err;
+
 	if (!urb || !urb->setup_packet)
-		return;
+		return 0;
 
 	if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
-		return;
+		return 0;
 
 	if (is_clear_halt_cmd(urb))
 		/* tweak clear_halt */
-		 tweak_clear_halt_cmd(urb);
+		err = tweak_clear_halt_cmd(urb);
 
 	else if (is_set_interface_cmd(urb))
 		/* tweak set_interface */
-		tweak_set_interface_cmd(urb);
+		err = tweak_set_interface_cmd(urb);
 
 	else if (is_set_configuration_cmd(urb))
 		/* tweak set_configuration */
-		tweak_set_configuration_cmd(urb);
+		err = tweak_set_configuration_cmd(urb);
 
 	else if (is_reset_device_cmd(urb))
-		tweak_reset_device_cmd(urb);
-	else
+		err = tweak_reset_device_cmd(urb);
+	else {
 		usbip_dbg_stub_rx("no need to tweak\n");
+		return 0;
+	}
+
+	return !err;
 }
 
 /*
@@ -468,6 +477,7 @@  static void stub_recv_cmd_submit(struct stub_device *sdev,
 	int support_sg = 1;
 	int np = 0;
 	int ret, i;
+	int is_tweaked;
 
 	if (pipe == -1)
 		return;
@@ -580,8 +590,7 @@  static void stub_recv_cmd_submit(struct stub_device *sdev,
 		priv->urbs[i]->pipe = pipe;
 		priv->urbs[i]->complete = stub_complete;
 
-		/* no need to submit an intercepted request, but harmless? */
-		tweak_special_requests(priv->urbs[i]);
+		is_tweaked = tweak_special_requests(priv->urbs[i]);
 
 		masking_bogus_flags(priv->urbs[i]);
 	}
@@ -594,22 +603,32 @@  static void stub_recv_cmd_submit(struct stub_device *sdev,
 
 	/* urb is now ready to submit */
 	for (i = 0; i < priv->num_urbs; i++) {
-		ret = usb_submit_urb(priv->urbs[i], GFP_KERNEL);
+		if (!is_tweaked) {
+			ret = usb_submit_urb(priv->urbs[i], GFP_KERNEL);
 
-		if (ret == 0)
-			usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
-					pdu->base.seqnum);
-		else {
-			dev_err(&udev->dev, "submit_urb error, %d\n", ret);
-			usbip_dump_header(pdu);
-			usbip_dump_urb(priv->urbs[i]);
+			if (ret == 0)
+				usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
+						pdu->base.seqnum);
+			else {
+				dev_err(&udev->dev, "submit_urb error, %d\n", ret);
+				usbip_dump_header(pdu);
+				usbip_dump_urb(priv->urbs[i]);
 
+				/*
+				 * Pessimistic.
+				 * This connection will be discarded.
+				 */
+				usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
+				break;
+			}
+		} else {
 			/*
-			 * Pessimistic.
-			 * This connection will be discarded.
+			 * An identical URB was already submitted in
+			 * tweak_special_requests(). Skip submitting this URB to not
+			 * duplicate the request.
 			 */
-			usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
-			break;
+			priv->urbs[i]->status = 0;
+			stub_complete(priv->urbs[i]);
 		}
 	}