Re: [Linux-kernel-mentees] [PATCH 05/15] usb: serial: cypress_m8: use usb_control_msg_recv() and usb_control_msg_send()
From: Johan Hovold <johan@kernel.org>
Date: 2020-12-04 09:38:14
Also in:
linux-usb, lkml
On Wed, Nov 04, 2020 at 12:16:53PM +0530, Himadri Pandya wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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.
quoted hunk ↗ jump to hunk
- 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 _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees