diff options
author | Christian Gromm <christian.gromm@microchip.com> | 2016-10-28 14:46:20 +0200 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-10-30 11:09:02 -0400 |
commit | 25e3854c83e67914d7b642215cd02fd8976a9dcc (patch) | |
tree | fb74e24b92113fe26e626068007ea68178e28901 | |
parent | b5367061920a4b9da98817081cada6e13b598e72 (diff) | |
download | linux-25e3854c83e67914d7b642215cd02fd8976a9dcc.tar.bz2 |
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 <christian.gromm@microchip.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | drivers/staging/most/hdm-usb/hdm_usb.c | 14 |
1 files changed, 14 insertions, 0 deletions
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; } |