From f42763dbdf043c9996dfabf6d167eab28e016eb8 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= Date: Fri, 30 May 2014 09:31:05 +0200 Subject: [PATCH] net: cdc_ncm: inform usbnet when rx buffers are reduced MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It doesn't matter whether the buffer size goes up or down. We have to keep usbnet and device syncronized to be able to split transfers at the correct boundaries. The spec allow skipping short packets when using max sized transfers. If we don't tell usbnet about our new expected rx buffer size, then it will merge and/or split NTBs. The driver does not support this, and the result will be lots of framing errors. Fix by always reallocating usbnet rx buffers when the rx_max value changes. Fixes: 68864abf08f0 ("net: cdc_ncm: support rx_max/tx_max updates when running") Signed-off-by: Bjørn Mork Signed-off-by: David S. Miller --- drivers/net/usb/cdc_ncm.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c index ff5b3a854898..5bce86a0d063 100644 --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -215,19 +215,12 @@ static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx) min, max, val); } - /* usbnet use these values for sizing rx queues */ - dev->rx_urb_size = val; - /* inform device about NTB input size changes */ if (val != ctx->rx_max) { __le32 dwNtbInMaxSize = cpu_to_le32(val); dev_info(&dev->intf->dev, "setting rx_max = %u\n", val); - /* need to unlink rx urbs before increasing buffer size */ - if (netif_running(dev->net) && dev->rx_urb_size > ctx->rx_max) - usbnet_unlink_rx_urbs(dev); - /* tell device to use new size */ if (usbnet_write_cmd(dev, USB_CDC_SET_NTB_INPUT_SIZE, USB_TYPE_CLASS | USB_DIR_OUT @@ -238,6 +231,13 @@ static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx) ctx->rx_max = val; } + /* usbnet use these values for sizing rx queues */ + if (dev->rx_urb_size != ctx->rx_max) { + dev->rx_urb_size = ctx->rx_max; + if (netif_running(dev->net)) + usbnet_unlink_rx_urbs(dev); + } + /* clamp new_tx to sane values */ min = ctx->max_datagram_size + ctx->max_ndp_size + sizeof(struct usb_cdc_ncm_nth16); max = min_t(u32, CDC_NCM_NTB_MAX_SIZE_TX, le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize));