From: Johan Hovold <johan@kernel.org>
To: Himadri Pandya <himadrispandya@gmail.com>
Cc: linux-usb@vger.kernel.org,
linux-kernel-mentees@lists.linuxfoundation.org, johan@kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [Linux-kernel-mentees] [PATCH 05/15] usb: serial: cypress_m8: use usb_control_msg_recv() and usb_control_msg_send()
Date: Fri, 4 Dec 2020 10:37:46 +0100 [thread overview]
Message-ID: <X8oDaiqW2K+t69JI@localhost> (raw)
In-Reply-To: <20201104064703.15123-6-himadrispandya@gmail.com>
On Wed, Nov 04, 2020 at 12:16:53PM +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/cypress_m8.c | 38 +++++++++++++++++----------------
> 1 file changed, 20 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c
> index cc028601c388..4d66cab8eece 100644
> --- a/drivers/usb/serial/cypress_m8.c
> +++ b/drivers/usb/serial/cypress_m8.c
> @@ -341,20 +341,21 @@ static int cypress_serial_control(struct tty_struct *tty,
> feature_buffer[4]);
>
> do {
> - retval = usb_control_msg(port->serial->dev,
> - usb_sndctrlpipe(port->serial->dev, 0),
> - HID_REQ_SET_REPORT,
> - USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
> - 0x0300, 0, feature_buffer,
> - feature_len, 500);
> + retval = usb_control_msg_send(port->serial->dev, 0,
> + HID_REQ_SET_REPORT,
> + USB_DIR_OUT |
> + USB_RECIP_INTERFACE |
> + USB_TYPE_CLASS, 0x0300,
> + 0, feature_buffer,
> + feature_len, 500,
> + GFP_KERNEL);
>
> if (tries++ >= 3)
> break;
>
> - } while (retval != feature_len &&
> - retval != -ENODEV);
> + } while (retval != -ENODEV);
Here you actually break the logic; after this change the driver will
always retry as the test for success is removed.
>
> - if (retval != feature_len) {
> + if (retval) {
> dev_err(dev, "%s - failed sending serial line settings - %d\n",
> __func__, retval);
> cypress_set_dead(port);
> @@ -379,19 +380,20 @@ static int cypress_serial_control(struct tty_struct *tty,
> }
> dev_dbg(dev, "%s - retrieving serial line settings\n", __func__);
> do {
> - retval = usb_control_msg(port->serial->dev,
> - usb_rcvctrlpipe(port->serial->dev, 0),
> - HID_REQ_GET_REPORT,
> - USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
> - 0x0300, 0, feature_buffer,
> - feature_len, 500);
> + retval = usb_control_msg_recv(port->serial->dev, 0,
> + HID_REQ_GET_REPORT,
> + USB_DIR_IN |
> + USB_RECIP_INTERFACE |
> + USB_TYPE_CLASS, 0x0300,
> + 0, feature_buffer,
> + feature_len, 500,
> + GFP_KERNEL);
>
> if (tries++ >= 3)
> break;
> - } while (retval != feature_len
> - && retval != -ENODEV);
> + } while (retval != -ENODEV);
Same here.
>
> - if (retval != feature_len) {
> + if (retval) {
> dev_err(dev, "%s - failed to retrieve serial line settings - %d\n",
> __func__, retval);
> cypress_set_dead(port);
As the driver is already using a DMA-able buffer and is reusing it for
every retry as well, this change is now introducing redundant memdup +
memcpy for each call.
I suggest just dropping this one.
Johan
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next prev parent reply other threads:[~2020-12-04 9:37 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-04 6:46 [Linux-kernel-mentees] [PATCH 00/15] usb: serial: avoid using usb_control_msg() directly Himadri Pandya
2020-11-04 6:46 ` [Linux-kernel-mentees] [PATCH 01/15] usb: serial: ark3116: use usb_control_msg_recv() and usb_control_msg_send() Himadri Pandya
2020-12-04 9:16 ` Johan Hovold
2020-11-04 6:46 ` [Linux-kernel-mentees] [PATCH 02/15] usb: serial: belkin_sa: use usb_control_msg_send() Himadri Pandya
2020-12-04 9:17 ` Johan Hovold
2020-11-04 6:46 ` [Linux-kernel-mentees] [PATCH 03/15] usb: serial: ch314: use usb_control_msg_recv() and usb_control_msg_send() Himadri Pandya
2020-12-04 9:24 ` Johan Hovold
2020-11-04 6:46 ` [Linux-kernel-mentees] [PATCH 04/15] usb: serial: cp210x: " Himadri Pandya
2020-12-04 9:34 ` Johan Hovold
2020-11-04 6:46 ` [Linux-kernel-mentees] [PATCH 05/15] usb: serial: cypress_m8: " Himadri Pandya
2020-12-04 9:37 ` Johan Hovold [this message]
2020-11-04 6:46 ` [Linux-kernel-mentees] [PATCH 06/15] usb: serial: f81232: " Himadri Pandya
2020-12-04 9:49 ` Johan Hovold
2020-11-04 6:46 ` [Linux-kernel-mentees] [PATCH 07/15] usb: serial: f81534: " Himadri Pandya
2020-12-04 9:55 ` Johan Hovold
2020-11-04 6:46 ` [Linux-kernel-mentees] [PATCH 08/15] usb: serial: ftdi_sio: " Himadri Pandya
2020-12-04 10:03 ` Johan Hovold
2020-11-04 6:46 ` [Linux-kernel-mentees] [PATCH 09/15] usb: serial: io_edgeport: " Himadri Pandya
2020-12-04 10:10 ` Johan Hovold
2020-11-04 6:46 ` [Linux-kernel-mentees] [PATCH 10/15] usb: serial: io_ti: " Himadri Pandya
2020-12-04 10:12 ` Johan Hovold
2020-11-04 6:46 ` [Linux-kernel-mentees] [PATCH 11/15] usb: serial: ipaq: use usb_control_msg_send() Himadri Pandya
2020-12-04 10:21 ` Johan Hovold
2020-11-04 6:47 ` [Linux-kernel-mentees] [PATCH 12/15] usb: serial: ipw: " Himadri Pandya
2020-12-04 10:27 ` Johan Hovold
2020-11-04 6:47 ` [Linux-kernel-mentees] [PATCH 13/15] usb: serial: iuu_phoenix: " Himadri Pandya
2020-12-04 10:28 ` Johan Hovold
2020-11-04 6:47 ` [Linux-kernel-mentees] [PATCH 14/15] usb: serial: keyspan_pda: use usb_control_msg_recv() and usb_control_msg_send() Himadri Pandya
2020-12-04 10:31 ` Johan Hovold
2020-11-04 6:47 ` [Linux-kernel-mentees] [PATCH 15/15] usb: serial: kl5kusb105: " Himadri Pandya
2020-12-04 10:37 ` Johan Hovold
2020-11-06 10:43 ` [Linux-kernel-mentees] [PATCH 00/15] usb: serial: avoid using usb_control_msg() directly Greg KH
2020-12-04 9:09 ` Johan Hovold
2020-12-24 10:01 ` Himadri Pandya
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