[PATCH v4 0/3] drivers: usb: misc: update to use usb_control_msg_{send|recv}() API

[PATCH v4 0/3] drivers: usb: misc: update to use usb_control_msg_{send|recv}() API

[Anant Thazhemadam]

The new usb_control_msg_{send|recv}() API provides a more convenient way
of using usb_control_msg() in some usecases. Using this, short reads are
considered as errors, data can be used off the stack, and the need for
the calling function to create a raw usb pipe is eliminated.
This patch series aims to update existing instances of usb_control_msg() 
in drivers/usb/misc/* to usb_control_msg_{send|recv}() appropriately
wherever it would be a good fit, and also update the return value
checking mechanisms in place (if any), as necessary so nothing breaks.

Changes in v4:

  * Drop all proposed changes to drivers (from v3) where the new API
    doesn't fit appropriately.
  * Update commit messages.
  * Link to v3:
      https://lore.kernel.org/linux-usb/YBF9exziI12OCSuA@hovoldconsulting.com/T/#m269ab33b52331c134bbbc77d13cb65c2194a6093

Changes in v3:

  * idmouse, emi26 and emi62 are left unchanged, and are not updated.
    -> since control transfers in idmouse are without a data stage, there's no
       real advantage in using the new helper here.
    -> in emi26, and emi62, FW_LOAD_SIZE = 1048 (> 1024). Thus, if we try to use the
       new helpers, it will result in either build warnings, or memory being allocated.

  * Link to v2:
      https://lore.kernel.org/linux-usb/20201130013103.2580467-1-anant.thazhemadam@gmail.com/T/


Changes in v2:

  * Buffer variables that were previously dynamically allocated are no
    longer dynamically allocated unless they have a variable length
    (since that threw a warning).

  * Link to v1:
        https://lore.kernel.org/linux-usb/20201129160612.1908074-1-anant.thazhemadam@gmail.com/ 



Anant Thazhemadam (3):
  usb: misc: ehset: update to use the usb_control_msg_{send|recv}() API
  usb: misc: ezusb: update to use usb_control_msg_send()
  usb: misc: usbsevseg: update to use usb_control_msg_send()

 drivers/usb/misc/ehset.c     | 76 +++++++++++++++---------------------
 drivers/usb/misc/ezusb.c     | 16 +-------
 drivers/usb/misc/usbsevseg.c | 60 ++++++++--------------------
 3 files changed, 51 insertions(+), 101 deletions(-)

-- 
2.25.1

[PATCH v4 1/3] usb: misc: ehset: update to use the usb_control_msg_{send|recv}() API

[Anant Thazhemadam]

The newer usb_control_msg_{send|recv}() API ensures that a short read
is treated as an error, data can be used off the stack, and raw usb
pipes need not be created in the calling functions.
For this reason, instances of usb_control_msg() have been replaced with
usb_control_msg_{recv|send}() appropriately.

Now, we also test for a short device descriptor (which USB core
should already have fetched if you get to probe this driver), but which
wasn't verified again here before.

Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
Reviewed-by: Peter Chen <peter.chen@nxp.com>
Reviewed-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/misc/ehset.c | 76 +++++++++++++++++-----------------------
 1 file changed, 32 insertions(+), 44 deletions(-)

diff --git a/drivers/usb/misc/ehset.c b/drivers/usb/misc/ehset.c
index 2752e1f4f4d0..f87890f9cd26 100644
--- a/drivers/usb/misc/ehset.c
+++ b/drivers/usb/misc/ehset.c
@@ -24,68 +24,57 @@ static int ehset_probe(struct usb_interface *intf,
 	int ret = -EINVAL;
 	struct usb_device *dev = interface_to_usbdev(intf);
 	struct usb_device *hub_udev = dev->parent;
-	struct usb_device_descriptor *buf;
+	struct usb_device_descriptor buf;
 	u8 portnum = dev->portnum;
 	u16 test_pid = le16_to_cpu(dev->descriptor.idProduct);
 
 	switch (test_pid) {
 	case TEST_SE0_NAK_PID:
-		ret = usb_control_msg(hub_udev, usb_sndctrlpipe(hub_udev, 0),
-					USB_REQ_SET_FEATURE, USB_RT_PORT,
-					USB_PORT_FEAT_TEST,
-					(USB_TEST_SE0_NAK << 8) | portnum,
-					NULL, 0, 1000);
+		ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE,
+					   USB_RT_PORT, USB_PORT_FEAT_TEST,
+					   (USB_TEST_SE0_NAK << 8) | portnum,
+					   NULL, 0, 1000, GFP_KERNEL);
 		break;
 	case TEST_J_PID:
-		ret = usb_control_msg(hub_udev, usb_sndctrlpipe(hub_udev, 0),
-					USB_REQ_SET_FEATURE, USB_RT_PORT,
-					USB_PORT_FEAT_TEST,
-					(USB_TEST_J << 8) | portnum,
-					NULL, 0, 1000);
+		ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE,
+					   USB_RT_PORT, USB_PORT_FEAT_TEST,
+					   (USB_TEST_J << 8) | portnum, NULL, 0,
+					   1000, GFP_KERNEL);
 		break;
 	case TEST_K_PID:
-		ret = usb_control_msg(hub_udev, usb_sndctrlpipe(hub_udev, 0),
-					USB_REQ_SET_FEATURE, USB_RT_PORT,
-					USB_PORT_FEAT_TEST,
-					(USB_TEST_K << 8) | portnum,
-					NULL, 0, 1000);
+		ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE,
+					   USB_RT_PORT, USB_PORT_FEAT_TEST,
+					   (USB_TEST_K << 8) | portnum, NULL, 0,
+					   1000, GFP_KERNEL);
 		break;
 	case TEST_PACKET_PID:
-		ret = usb_control_msg(hub_udev, usb_sndctrlpipe(hub_udev, 0),
-					USB_REQ_SET_FEATURE, USB_RT_PORT,
-					USB_PORT_FEAT_TEST,
-					(USB_TEST_PACKET << 8) | portnum,
-					NULL, 0, 1000);
+		ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE,
+					   USB_RT_PORT, USB_PORT_FEAT_TEST,
+					   (USB_TEST_PACKET << 8) | portnum,
+					   NULL, 0, 1000, GFP_KERNEL);
 		break;
 	case TEST_HS_HOST_PORT_SUSPEND_RESUME:
 		/* Test: wait for 15secs -> suspend -> 15secs delay -> resume */
 		msleep(15 * 1000);
-		ret = usb_control_msg(hub_udev, usb_sndctrlpipe(hub_udev, 0),
-					USB_REQ_SET_FEATURE, USB_RT_PORT,
-					USB_PORT_FEAT_SUSPEND, portnum,
-					NULL, 0, 1000);
+		ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE,
+					   USB_RT_PORT, USB_PORT_FEAT_SUSPEND,
+					   portnum, NULL, 0, 1000, GFP_KERNEL);
 		if (ret < 0)
 			break;
 
 		msleep(15 * 1000);
-		ret = usb_control_msg(hub_udev, usb_sndctrlpipe(hub_udev, 0),
-					USB_REQ_CLEAR_FEATURE, USB_RT_PORT,
-					USB_PORT_FEAT_SUSPEND, portnum,
-					NULL, 0, 1000);
+		ret = usb_control_msg_send(hub_udev, 0, USB_REQ_CLEAR_FEATURE,
+					   USB_RT_PORT, USB_PORT_FEAT_SUSPEND,
+					   portnum, NULL, 0, 1000, GFP_KERNEL);
 		break;
 	case TEST_SINGLE_STEP_GET_DEV_DESC:
 		/* Test: wait for 15secs -> GetDescriptor request */
 		msleep(15 * 1000);
-		buf = kmalloc(USB_DT_DEVICE_SIZE, GFP_KERNEL);
-		if (!buf)
-			return -ENOMEM;
 
-		ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
-					USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
-					USB_DT_DEVICE << 8, 0,
-					buf, USB_DT_DEVICE_SIZE,
-					USB_CTRL_GET_TIMEOUT);
-		kfree(buf);
+		ret = usb_control_msg_recv(dev, 0, USB_REQ_GET_DESCRIPTOR,
+					   USB_DIR_IN, USB_DT_DEVICE << 8, 0,
+					   &buf, USB_DT_DEVICE_SIZE,
+					   USB_CTRL_GET_TIMEOUT, GFP_KERNEL);
 		break;
 	case TEST_SINGLE_STEP_SET_FEATURE:
 		/*
@@ -100,11 +89,10 @@ static int ehset_probe(struct usb_interface *intf,
 			break;
 		}
 
-		ret = usb_control_msg(hub_udev, usb_sndctrlpipe(hub_udev, 0),
-					USB_REQ_SET_FEATURE, USB_RT_PORT,
-					USB_PORT_FEAT_TEST,
-					(6 << 8) | portnum,
-					NULL, 0, 60 * 1000);
+		ret = usb_control_msg_send(hub_udev, 0, USB_REQ_SET_FEATURE,
+					   USB_RT_PORT, USB_PORT_FEAT_TEST,
+					   (6 << 8) | portnum, NULL, 0,
+					   60 * 1000, GFP_KERNEL);
 
 		break;
 	default:
@@ -112,7 +100,7 @@ static int ehset_probe(struct usb_interface *intf,
 			__func__, test_pid);
 	}
 
-	return (ret < 0) ? ret : 0;
+	return ret;
 }
 
 static void ehset_disconnect(struct usb_interface *intf)
-- 
2.25.1

[PATCH v4 2/3] usb: misc: ezusb: update to use usb_control_msg_send()

[Anant Thazhemadam]

The newer usb_control_msg_{send|recv}() API ensures that a short read is
treated as an error, data can be used off the stack, and raw usb pipes need
not be created in the calling functions.
For this reason, the instance of usb_control_msg() has been replaced with
usb_control_msg_send() appropriately.

Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
Reviewed-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/misc/ezusb.c | 16 ++--------------
 1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/drivers/usb/misc/ezusb.c b/drivers/usb/misc/ezusb.c
index f058d8029761..78aaee56c2b7 100644
--- a/drivers/usb/misc/ezusb.c
+++ b/drivers/usb/misc/ezusb.c
@@ -31,24 +31,12 @@ static const struct ezusb_fx_type ezusb_fx1 = {
 static int ezusb_writememory(struct usb_device *dev, int address,
 				unsigned char *data, int length, __u8 request)
 {
-	int result;
-	unsigned char *transfer_buffer;
-
 	if (!dev)
 		return -ENODEV;
 
-	transfer_buffer = kmemdup(data, length, GFP_KERNEL);
-	if (!transfer_buffer) {
-		dev_err(&dev->dev, "%s - kmalloc(%d) failed.\n",
-							__func__, length);
-		return -ENOMEM;
-	}
-	result = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
+	return usb_control_msg_send(dev, 0, request,
 				 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
-				 address, 0, transfer_buffer, length, 3000);
-
-	kfree(transfer_buffer);
-	return result;
+				 address, 0, data, length, 3000, GFP_KERNEL);
 }
 
 static int ezusb_set_reset(struct usb_device *dev, unsigned short cpucs_reg,
-- 
2.25.1

[PATCH v4 3/3] usb: misc: usbsevseg: update to use usb_control_msg_send()

[Anant Thazhemadam]

The newer usb_control_msg_{send|recv}() API ensures that a short read is 
treated as an error, data can be used off the stack, and raw usb pipes 
need not be created in the calling functions.
For this reason, instances of usb_control_msg() have been replaced with
usb_control_msg_send() appropriately.

Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
---
 drivers/usb/misc/usbsevseg.c | 60 ++++++++++--------------------------
 1 file changed, 17 insertions(+), 43 deletions(-)

diff --git a/drivers/usb/misc/usbsevseg.c b/drivers/usb/misc/usbsevseg.c
index 551074f5b7ad..4bc816bb09bb 100644
--- a/drivers/usb/misc/usbsevseg.c
+++ b/drivers/usb/misc/usbsevseg.c
@@ -74,15 +74,10 @@ static void update_display_powered(struct usb_sevsegdev *mydev)
 	if (mydev->shadow_power != 1)
 		return;
 
-	rc = usb_control_msg(mydev->udev,
-			usb_sndctrlpipe(mydev->udev, 0),
-			0x12,
-			0x48,
-			(80 * 0x100) + 10, /*  (power mode) */
-			(0x00 * 0x100) + (mydev->powered ? 1 : 0),
-			NULL,
-			0,
-			2000);
+	rc = usb_control_msg_send(mydev->udev, 0, 0x12, 0x48,
+				  (80 * 0x100) + 10, /*  (power mode) */
+				  (0x00 * 0x100) + (mydev->powered ? 1 : 0),
+				  NULL, 0, 2000, GFP_KERNEL);
 	if (rc < 0)
 		dev_dbg(&mydev->udev->dev, "power retval = %d\n", rc);
 
@@ -99,15 +94,10 @@ static void update_display_mode(struct usb_sevsegdev *mydev)
 	if(mydev->shadow_power != 1)
 		return;
 
-	rc = usb_control_msg(mydev->udev,
-			usb_sndctrlpipe(mydev->udev, 0),
-			0x12,
-			0x48,
-			(82 * 0x100) + 10, /* (set mode) */
-			(mydev->mode_msb * 0x100) + mydev->mode_lsb,
-			NULL,
-			0,
-			2000);
+	rc = usb_control_msg_send(mydev->udev, 0, 0x12, 0x48,
+				  (82 * 0x100) + 10, /* (set mode) */
+				  (mydev->mode_msb * 0x100) + mydev->mode_lsb,
+				  NULL, 0, 2000, GFP_NOIO);
 
 	if (rc < 0)
 		dev_dbg(&mydev->udev->dev, "mode retval = %d\n", rc);
@@ -117,48 +107,32 @@ static void update_display_visual(struct usb_sevsegdev *mydev, gfp_t mf)
 {
 	int rc;
 	int i;
-	unsigned char *buffer;
+	unsigned char buffer[MAXLEN] = {0};
 	u8 decimals = 0;
 
 	if(mydev->shadow_power != 1)
 		return;
 
-	buffer = kzalloc(MAXLEN, mf);
-	if (!buffer)
-		return;
-
 	/* The device is right to left, where as you write left to right */
 	for (i = 0; i < mydev->textlength; i++)
 		buffer[i] = mydev->text[mydev->textlength-1-i];
 
-	rc = usb_control_msg(mydev->udev,
-			usb_sndctrlpipe(mydev->udev, 0),
-			0x12,
-			0x48,
-			(85 * 0x100) + 10, /* (write text) */
-			(0 * 0x100) + mydev->textmode, /* mode  */
-			buffer,
-			mydev->textlength,
-			2000);
+	rc = usb_control_msg_send(mydev->udev, 0, 0x12, 0x48,
+				  (85 * 0x100) + 10, /* (write text) */
+				  (0 * 0x100) + mydev->textmode, /* mode  */
+				  &buffer, mydev->textlength, 2000, mf);
 
 	if (rc < 0)
 		dev_dbg(&mydev->udev->dev, "write retval = %d\n", rc);
 
-	kfree(buffer);
-
 	/* The device is right to left, where as you write left to right */
 	for (i = 0; i < sizeof(mydev->decimals); i++)
 		decimals |= mydev->decimals[i] << i;
 
-	rc = usb_control_msg(mydev->udev,
-			usb_sndctrlpipe(mydev->udev, 0),
-			0x12,
-			0x48,
-			(86 * 0x100) + 10, /* (set decimal) */
-			(0 * 0x100) + decimals, /* decimals */
-			NULL,
-			0,
-			2000);
+	rc = usb_control_msg_send(mydev->udev, 0, 0x12, 0x48,
+				  (86 * 0x100) + 10, /* (set decimal) */
+				  (0 * 0x100) + decimals, /* decimals */
+				  NULL, 0, 2000, mf);
 
 	if (rc < 0)
 		dev_dbg(&mydev->udev->dev, "decimal retval = %d\n", rc);
-- 
2.25.1