| Message ID | 20201104064703.15123-4-himadrispandya@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | usb: serial: avoid using usb_control_msg() directly | expand |
On Wed, Nov 04, 2020 at 12:16:51PM +0530, Himadri Pandya wrote: > The new usb_control_msg_recv() and usb_control_msg_send() nicely wraps > usb_control_msg() with proper error check. Hence use the wrappers > instead of calling usb_control_msg() directly. > > Signed-off-by: Himadri Pandya <himadrispandya@gmail.com> > --- > drivers/usb/serial/ch341.c | 45 ++++++++++++-------------------------- > 1 file changed, 14 insertions(+), 31 deletions(-) > > diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c > index a2e2f56c88cd..58c5d3ce4f75 100644 > --- a/drivers/usb/serial/ch341.c > +++ b/drivers/usb/serial/ch341.c > @@ -111,10 +111,10 @@ static int ch341_control_out(struct usb_device *dev, u8 request, > dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x)\n", __func__, > request, value, index); > > - r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request, > - USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT, > - value, index, NULL, 0, DEFAULT_TIMEOUT); > - if (r < 0) > + r = usb_control_msg_send(dev, 0, request, USB_TYPE_VENDOR | > + USB_RECIP_DEVICE | USB_DIR_OUT, value, index, > + NULL, 0, DEFAULT_TIMEOUT, GFP_KERNEL); > + if (r) > dev_err(&dev->dev, "failed to send control message: %d\n", r); > > return r; > @@ -129,23 +129,14 @@ static int ch341_control_in(struct usb_device *dev, > dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x,%u)\n", __func__, > request, value, index, bufsize); > > - r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request, > - USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN, > - value, index, buf, bufsize, DEFAULT_TIMEOUT); > - if (r < (int)bufsize) { > - if (r >= 0) { > - dev_err(&dev->dev, > - "short control message received (%d < %u)\n", > - r, bufsize); > - r = -EIO; > - } > - > + r = usb_control_msg_recv(dev, 0, request, USB_TYPE_VENDOR | > + USB_RECIP_DEVICE | USB_DIR_IN, value, index, > + buf, bufsize, DEFAULT_TIMEOUT, GFP_KERNEL); > + if (r) > dev_err(&dev->dev, "failed to receive control message: %d\n", > r); > - return r; > - } > > - return 0; > + return r; > } The callers of these functions are allocating temporary transfers buffer for each request so this is a case where the new helpers may be of worth if you fix up the callers as well (otherwise, you're adding redundant memdup + memcpy for each call here). > > #define CH341_CLKRATE 48000000 > @@ -343,22 +334,18 @@ static int ch341_detect_quirks(struct usb_serial_port *port) > struct usb_device *udev = port->serial->dev; > const unsigned int size = 2; > unsigned long quirks = 0; > - char *buffer; > + u8 buffer[2]; > int r; > > - buffer = kmalloc(size, GFP_KERNEL); > - if (!buffer) > - return -ENOMEM; > - > /* > * A subset of CH34x devices does not support all features. The > * prescaler is limited and there is no support for sending a RS232 > * break condition. A read failure when trying to set up the latter is > * used to detect these devices. > */ > - r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), CH341_REQ_READ_REG, > - USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN, > - CH341_REG_BREAK, 0, buffer, size, DEFAULT_TIMEOUT); > + r = usb_control_msg_recv(udev, 0, CH341_REQ_READ_REG, USB_TYPE_VENDOR | > + USB_RECIP_DEVICE | USB_DIR_IN, CH341_REG_BREAK, > + 0, &buffer, size, DEFAULT_TIMEOUT, GFP_KERNEL); > if (r == -EPIPE) { > dev_info(&port->dev, "break control not supported, using simulated break\n"); > quirks = CH341_QUIRK_LIMITED_PRESCALER | CH341_QUIRK_SIMULATE_BREAK; > @@ -366,17 +353,13 @@ static int ch341_detect_quirks(struct usb_serial_port *port) > goto out; > } > > - if (r != size) { > - if (r >= 0) > - r = -EIO; > + if (r) { > dev_err(&port->dev, "failed to read break control: %d\n", r); > goto out; > } > > r = 0; > out: > - kfree(buffer); > - > if (quirks) { > dev_dbg(&port->dev, "enabling quirk flags: 0x%02lx\n", quirks); > priv->quirks |= quirks; This is a good example of when to use the helpers. But it seems you should remove the "r = 0" and "out" label as well, right? Johan
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c index a2e2f56c88cd..58c5d3ce4f75 100644 --- a/drivers/usb/serial/ch341.c +++ b/drivers/usb/serial/ch341.c @@ -111,10 +111,10 @@ static int ch341_control_out(struct usb_device *dev, u8 request, dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x)\n", __func__, request, value, index); - r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request, - USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT, - value, index, NULL, 0, DEFAULT_TIMEOUT); - if (r < 0) + r = usb_control_msg_send(dev, 0, request, USB_TYPE_VENDOR | + USB_RECIP_DEVICE | USB_DIR_OUT, value, index, + NULL, 0, DEFAULT_TIMEOUT, GFP_KERNEL); + if (r) dev_err(&dev->dev, "failed to send control message: %d\n", r); return r; @@ -129,23 +129,14 @@ static int ch341_control_in(struct usb_device *dev, dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x,%u)\n", __func__, request, value, index, bufsize); - r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request, - USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN, - value, index, buf, bufsize, DEFAULT_TIMEOUT); - if (r < (int)bufsize) { - if (r >= 0) { - dev_err(&dev->dev, - "short control message received (%d < %u)\n", - r, bufsize); - r = -EIO; - } - + r = usb_control_msg_recv(dev, 0, request, USB_TYPE_VENDOR | + USB_RECIP_DEVICE | USB_DIR_IN, value, index, + buf, bufsize, DEFAULT_TIMEOUT, GFP_KERNEL); + if (r) dev_err(&dev->dev, "failed to receive control message: %d\n", r); - return r; - } - return 0; + return r; } #define CH341_CLKRATE 48000000 @@ -343,22 +334,18 @@ static int ch341_detect_quirks(struct usb_serial_port *port) struct usb_device *udev = port->serial->dev; const unsigned int size = 2; unsigned long quirks = 0; - char *buffer; + u8 buffer[2]; int r; - buffer = kmalloc(size, GFP_KERNEL); - if (!buffer) - return -ENOMEM; - /* * A subset of CH34x devices does not support all features. The * prescaler is limited and there is no support for sending a RS232 * break condition. A read failure when trying to set up the latter is * used to detect these devices. */ - r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), CH341_REQ_READ_REG, - USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN, - CH341_REG_BREAK, 0, buffer, size, DEFAULT_TIMEOUT); + r = usb_control_msg_recv(udev, 0, CH341_REQ_READ_REG, USB_TYPE_VENDOR | + USB_RECIP_DEVICE | USB_DIR_IN, CH341_REG_BREAK, + 0, &buffer, size, DEFAULT_TIMEOUT, GFP_KERNEL); if (r == -EPIPE) { dev_info(&port->dev, "break control not supported, using simulated break\n"); quirks = CH341_QUIRK_LIMITED_PRESCALER | CH341_QUIRK_SIMULATE_BREAK; @@ -366,17 +353,13 @@ static int ch341_detect_quirks(struct usb_serial_port *port) goto out; } - if (r != size) { - if (r >= 0) - r = -EIO; + if (r) { dev_err(&port->dev, "failed to read break control: %d\n", r); goto out; } r = 0; out: - kfree(buffer); - if (quirks) { dev_dbg(&port->dev, "enabling quirk flags: 0x%02lx\n", quirks); priv->quirks |= quirks;
The new usb_control_msg_recv() and usb_control_msg_send() nicely wraps usb_control_msg() with proper error check. Hence use the wrappers instead of calling usb_control_msg() directly. Signed-off-by: Himadri Pandya <himadrispandya@gmail.com> --- drivers/usb/serial/ch341.c | 45 ++++++++++++-------------------------- 1 file changed, 14 insertions(+), 31 deletions(-)