From: Christian Gromm Date: Fri, 28 Oct 2016 12:46:20 +0000 (+0200) Subject: staging: most: hdm-usb: add comment X-Git-Tag: v4.10-rc1~148^2~377 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=25e3854c83e67914d7b642215cd02fd8976a9dcc;p=karo-tx-linux.git staging: most: hdm-usb: add comment This patch adds a comment to function hdm_configure_channel() to clarify its execution paths. Signed-off-by: Christian Gromm Reported-by: Dan Carpenter Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/most/hdm-usb/hdm_usb.c b/drivers/staging/most/hdm-usb/hdm_usb.c index 34336465c5fa..d6db0bd65be0 100644 --- a/drivers/staging/most/hdm-usb/hdm_usb.c +++ b/drivers/staging/most/hdm-usb/hdm_usb.c @@ -634,6 +634,15 @@ _error: * @iface: interface * @channel: channel ID * @conf: structure that holds the configuration information + * + * The attached network interface controller (NIC) supports a padding mode + * to avoid short packets on USB, hence increasing the performance due to a + * lower interrupt load. This mode is default for synchronous data and can + * be switched on for isochronous data. In case padding is active the + * driver needs to know the frame size of the payload in order to calculate + * the number of bytes it needs to pad when transmitting or to cut off when + * receiving data. + * */ static int hdm_configure_channel(struct most_interface *iface, int channel, struct most_channel_config *conf) @@ -667,6 +676,11 @@ static int hdm_configure_channel(struct most_interface *iface, int channel, !(conf->data_type == MOST_CH_ISOC && conf->packets_per_xact != 0xFF)) { mdev->padding_active[channel] = false; + /* + * Since the NIC's padding mode is not going to be + * used, we can skip the frame size calculations and + * move directly on to exit. + */ goto exit; }