lkml.org 
[lkml]   [2021]   [Oct]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v3 1/2] USB: serial: ch314: use usb_control_msg_recv() and usb_control_msg_send()
On Wed, Oct 27, 2021 at 03:28:42PM +0200, Himadri Pandya wrote:
> On Wed, Oct 27, 2021 at 3:04 PM Johan Hovold <johan@kernel.org> wrote:
> > On Fri, Oct 01, 2021 at 08:57:19AM +0200, Himadri Pandya wrote:

> > > @@ -287,23 +277,18 @@ static int ch341_set_handshake(struct usb_device *dev, u8 control)
> > > static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
> > > {
> > > const unsigned int size = 2;
> > > - char *buffer;
> > > + u8 buffer[2];
> > > int r;
> > > unsigned long flags;
> > >
> > > - buffer = kmalloc(size, GFP_KERNEL);
> > > - if (!buffer)
> > > - return -ENOMEM;
> > > -
> > > r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x0706, 0, buffer, size);
> > > - if (r < 0)
> > > - goto out;
> > > + if (r)
> > > + return r;
> > >
> > > spin_lock_irqsave(&priv->lock, flags);
> > > priv->msr = (~(*buffer)) & CH341_BITS_MODEM_STAT;
> > > spin_unlock_irqrestore(&priv->lock, flags);
> > >
> > > -out: kfree(buffer);
> > > return r;
> >
> > This should now be
> >
> > return 0;
> >
>
> Yes. The function was returning the negative error value before the
> change. But now it doesn't need to as we are already taking care of it
> in the wrapper.

It has more to do with the fact that we now return early on errors so r
will always be zero here. It's better to be explicit about that.

> > > }
> > >
> > > @@ -312,30 +297,25 @@ out: kfree(buffer);
> > > static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
> > > {
> > > const unsigned int size = 2;
> > > - char *buffer;
> > > + u8 buffer[2];
> > > int r;
> > >
> > > - buffer = kmalloc(size, GFP_KERNEL);
> > > - if (!buffer)
> > > - return -ENOMEM;
> > > -
> > > /* expect two bytes 0x27 0x00 */
> > > r = ch341_control_in(dev, CH341_REQ_READ_VERSION, 0, 0, buffer, size);
> > > - if (r < 0)
> > > - goto out;
> > > + if (r)
> > > + return r;
> > > dev_dbg(&dev->dev, "Chip version: 0x%02x\n", buffer[0]);
> > >
> > > r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT, 0, 0);
> > > - if (r < 0)
> > > - goto out;
> > > + if (r)
> > > + return r;
> >
> > Now an unrelated change.
>
> I think it is a related change because we are removing the out label.

Sorry, I meant that the (r < 0) change was unrelated since you're no
longer touching ch341_control_out(). The return is indeed still needed.

> > > @@ -647,23 +611,19 @@ static void ch341_break_ctl(struct tty_struct *tty, int break_state)
> > > struct ch341_private *priv = usb_get_serial_port_data(port);
> > > int r;
> > > uint16_t reg_contents;
> > > - uint8_t *break_reg;
> > > + uint8_t break_reg[2];
> > >
> > > if (priv->quirks & CH341_QUIRK_SIMULATE_BREAK) {
> > > ch341_simulate_break(tty, break_state);
> > > return;
> > > }
> > >
> > > - break_reg = kmalloc(2, GFP_KERNEL);
> > > - if (!break_reg)
> > > - return;
> > > -
> > > r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
> > > ch341_break_reg, 0, break_reg, 2);
> > > - if (r < 0) {
> > > + if (r) {
> > > dev_err(&port->dev, "%s - USB control read error (%d)\n",
> > > __func__, r);
> > > - goto out;
> > > + return;
> > > }
> > > dev_dbg(&port->dev, "%s - initial ch341 break register contents - reg1: %x, reg2: %x\n",
> > > __func__, break_reg[0], break_reg[1]);
> > > @@ -681,11 +641,9 @@ static void ch341_break_ctl(struct tty_struct *tty, int break_state)
> > > reg_contents = get_unaligned_le16(break_reg);
> > > r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
> > > ch341_break_reg, reg_contents);
> > > - if (r < 0)
> > > + if (r)
> >
> > Now also an unrelated change.
> >
>
> Maybe I misunderstood your comments on v2. I thought you asked to get
> rid of the out labels in callers.

Yes, but as above I'm referring to the (r < 0) change for
ch341_control_out() which is now unrelated to the rest of the patch.

Johan

\
 
 \ /
  Last update: 2021-10-27 15:38    [W:0.051 / U:0.104 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site