[PATCH 0/6] USB: serial: drop short control-transfer checks

[PATCH 0/6] USB: serial: drop short control-transfer checks

[Johan Hovold]

There's no need to check for short control transfers when sending data
so remove the redundant sanity checks from the drivers that had them.

Included is also a related fix of a copy-paste error in a debug message.

Johan


Johan Hovold (6):
  USB: serial: mxuport: drop short control-transfer check
  USB: serial: upd78f0730: drop short control-transfer check
  USB: serial: io_ti: drop short control-transfer check
  USB: serial: io_ti: fix a debug-message copy-paste error
  USB: serial: f81232: drop short control-transfer checks
  USB: serial: f81534: drop short control-transfer check

 drivers/usb/serial/f81232.c     | 12 ++----------
 drivers/usb/serial/f81534.c     |  4 +---
 drivers/usb/serial/io_ti.c      |  8 ++------
 drivers/usb/serial/mxuport.c    |  7 -------
 drivers/usb/serial/upd78f0730.c |  5 +----
 5 files changed, 6 insertions(+), 30 deletions(-)

-- 
2.26.2

[PATCH 1/6] USB: serial: mxuport: drop short control-transfer check

[Johan Hovold]

There's no need to check for short control transfers when sending data
so remove the redundant sanity check.

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/serial/mxuport.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/drivers/usb/serial/mxuport.c b/drivers/usb/serial/mxuport.c
index 5d38c2a0f590..eb45a9b0005c 100644
--- a/drivers/usb/serial/mxuport.c
+++ b/drivers/usb/serial/mxuport.c
@@ -261,13 +261,6 @@ static int mxuport_send_ctrl_data_urb(struct usb_serial *serial,
 		return status;
 	}
 
-	if (status != size) {
-		dev_err(&serial->interface->dev,
-			"%s - short write (%d / %zd)\n",
-			__func__, status, size);
-		return -EIO;
-	}
-
 	return 0;
 }
 
-- 
2.26.2

[PATCH 2/6] USB: serial: upd78f0730: drop short control-transfer check

[Johan Hovold]

There's no need to check for short control transfers when sending data
so remove the redundant sanity check.

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/serial/upd78f0730.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/usb/serial/upd78f0730.c b/drivers/usb/serial/upd78f0730.c
index 0a2268c479af..1ca9c1881621 100644
--- a/drivers/usb/serial/upd78f0730.c
+++ b/drivers/usb/serial/upd78f0730.c
@@ -145,14 +145,11 @@ static int upd78f0730_send_ctl(struct usb_serial_port *port,
 
 	kfree(buf);
 
-	if (res != size) {
+	if (res < 0) {
 		struct device *dev = &port->dev;
 
 		dev_err(dev, "failed to send control request %02x: %d\n",
 			*(u8 *)data, res);
-		/* The maximum expected length of a transfer is 6 bytes */
-		if (res >= 0)
-			res = -EIO;
 
 		return res;
 	}
-- 
2.26.2

[PATCH 3/6] USB: serial: io_ti: drop short control-transfer check

[Johan Hovold]

There's no need to check for short control transfers when sending data
so remove the redundant sanity check.

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/serial/io_ti.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c
index c327d4cf7928..0c4062698603 100644
--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -283,11 +283,7 @@ static int ti_vsend_sync(struct usb_device *dev, u8 request, u16 value,
 			value, index, data, size, timeout);
 	if (status < 0)
 		return status;
-	if (status != size) {
-		dev_dbg(&dev->dev, "%s - wanted to write %d, but only wrote %d\n",
-			__func__, size, status);
-		return -ECOMM;
-	}
+
 	return 0;
 }
 
-- 
2.26.2

[PATCH 4/6] USB: serial: io_ti: fix a debug-message copy-paste error

[Johan Hovold]

Fix a copy-paste error in the ti_vread_sync() debug message.

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/serial/io_ti.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c
index 0c4062698603..0bbfa47e04b7 100644
--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -266,7 +266,7 @@ static int ti_vread_sync(struct usb_device *dev, __u8 request,
 	if (status < 0)
 		return status;
 	if (status != size) {
-		dev_dbg(&dev->dev, "%s - wanted to write %d, but only wrote %d\n",
+		dev_dbg(&dev->dev, "%s - wanted to read %d, but only read %d\n",
 			__func__, size, status);
 		return -ECOMM;
 	}
-- 
2.26.2

[PATCH 5/6] USB: serial: f81232: drop short control-transfer checks

[Johan Hovold]

There's no need to check for short control transfers when sending data
so remove the redundant sanity checks.

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/serial/f81232.c | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
index 0c7eacc630e0..6a8f39147d8e 100644
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -192,13 +192,9 @@ static int f81232_set_register(struct usb_serial_port *port, u16 reg, u8 val)
 				tmp,
 				sizeof(val),
 				USB_CTRL_SET_TIMEOUT);
-	if (status != sizeof(val)) {
+	if (status < 0) {
 		dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
-
-		if (status < 0)
-			status = usb_translate_errors(status);
-		else
-			status = -EIO;
+		status = usb_translate_errors(status);
 	} else {
 		status = 0;
 	}
@@ -886,10 +882,6 @@ static int f81534a_ctrl_set_register(struct usb_interface *intf, u16 reg,
 			status = usb_translate_errors(status);
 			if (status == -EIO)
 				continue;
-		} else if (status != size) {
-			/* Retry on short transfers */
-			status = -EIO;
-			continue;
 		} else {
 			status = 0;
 		}
-- 
2.26.2

[PATCH 6/6] USB: serial: f81534: drop short control-transfer check

[Johan Hovold]

There's no need to check for short control transfers when sending data
so remove the redundant sanity check.

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/serial/f81534.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/usb/serial/f81534.c b/drivers/usb/serial/f81534.c
index 5661fd03e545..dd7e55e822ef 100644
--- a/drivers/usb/serial/f81534.c
+++ b/drivers/usb/serial/f81534.c
@@ -235,11 +235,9 @@ static int f81534_set_register(struct usb_serial *serial, u16 reg, u8 data)
 					 USB_TYPE_VENDOR | USB_DIR_OUT,
 					 reg, 0, tmp, sizeof(u8),
 					 F81534_USB_TIMEOUT);
-		if (status > 0) {
+		if (status == sizeof(u8)) {
 			status = 0;
 			break;
-		} else if (status == 0) {
-			status = -EIO;
 		}
 	}
 
-- 
2.26.2

Re: [PATCH 0/6] USB: serial: drop short control-transfer checks

[Johan Hovold]

Hi Himadri,

On Mon, Jan 18, 2021 at 12:14:20PM +0100, Johan Hovold wrote:
> There's no need to check for short control transfers when sending data
> so remove the redundant sanity checks from the drivers that had them.
> 
> Included is also a related fix of a copy-paste error in a debug message.
> 
> Johan
> 
> 
> Johan Hovold (6):
>   USB: serial: mxuport: drop short control-transfer check
>   USB: serial: upd78f0730: drop short control-transfer check
>   USB: serial: io_ti: drop short control-transfer check
>   USB: serial: io_ti: fix a debug-message copy-paste error
>   USB: serial: f81232: drop short control-transfer checks
>   USB: serial: f81534: drop short control-transfer check
> 
>  drivers/usb/serial/f81232.c     | 12 ++----------
>  drivers/usb/serial/f81534.c     |  4 +---
>  drivers/usb/serial/io_ti.c      |  8 ++------
>  drivers/usb/serial/mxuport.c    |  7 -------
>  drivers/usb/serial/upd78f0730.c |  5 +----
>  5 files changed, 6 insertions(+), 30 deletions(-)

I intended to CC you on this series, but forgot to do so before hitting
send.

The series can be found here:

	https://lore.kernel.org/r/20210118111426.5147-1-johan@kernel.org

I checked to make sure it doesn't interfere too much with your revised
series.

Johan

Re: [PATCH 0/6] USB: serial: drop short control-transfer checks

[Greg Kroah-Hartman]

On Mon, Jan 18, 2021 at 12:14:20PM +0100, Johan Hovold wrote:
> There's no need to check for short control transfers when sending data
> so remove the redundant sanity checks from the drivers that had them.

It seems impossible to do a "short write", so I wonder why we even check
it...

Anyway, nice cleanups:

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Re: [PATCH 0/6] USB: serial: drop short control-transfer checks

[Johan Hovold]

On Mon, Jan 18, 2021 at 01:46:28PM +0100, Greg Kroah-Hartman wrote:
> On Mon, Jan 18, 2021 at 12:14:20PM +0100, Johan Hovold wrote:
> > There's no need to check for short control transfers when sending data
> > so remove the redundant sanity checks from the drivers that had them.
> 
> It seems impossible to do a "short write", so I wonder why we even check
> it...

Right, and this series removes precisely those redundant checks. Or what
did you mean? :)

> Anyway, nice cleanups:
> 
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Thanks for reviewing, now applied.

Johan