diff options
| -rw-r--r-- | recipes-kernel/linux/linux-toradex-upstream/0001-usb-gadget-f_ncm-Apply-workaround-for-packet-cloggin.patch | 68 | ||||
| -rw-r--r-- | recipes-kernel/linux/linux-toradex-upstream_mainline.bb | 3 |
2 files changed, 70 insertions, 1 deletions
diff --git a/recipes-kernel/linux/linux-toradex-upstream/0001-usb-gadget-f_ncm-Apply-workaround-for-packet-cloggin.patch b/recipes-kernel/linux/linux-toradex-upstream/0001-usb-gadget-f_ncm-Apply-workaround-for-packet-cloggin.patch new file mode 100644 index 0000000..dfdd723 --- /dev/null +++ b/recipes-kernel/linux/linux-toradex-upstream/0001-usb-gadget-f_ncm-Apply-workaround-for-packet-cloggin.patch @@ -0,0 +1,68 @@ +From 2147c8ddfaa746cdb8857db070f907fa9abfcb60 Mon Sep 17 00:00:00 2001 +From: Hiago De Franco <hiago.franco@toradex.com> +Date: Tue, 19 Dec 2023 11:52:07 -0300 +Subject: [PATCH] usb: gadget: f_ncm: Apply workaround for packet clogging + +The existing size of 32 is causing significant slowness and freezing when +utilizing the NCM protocol with a VNC client. This issue likely arises +because the VNC protocol relies on sending numerous small packets, which +accumulate until the 16KB limit is reached, leading to transmission +delays. + +By decreasing TX_MAX_NUM_DPE to 4, we ensure that the NCM driver transmits +packets at a reduced interval, thereby resolving the VNC performance +issues. To comprehend how these packets are sent, refer to the code +snippet below from f_ncm.c: + +``` + /* If the new skb is too big for the current NCM NTB then + * set the current stored skb to be sent now and clear it + * ready for new data. + * NOTE: Assume maximum align for speed of calculation. + */ + if (ncm->skb_tx_data + && (ncm->ndp_dgram_count >= TX_MAX_NUM_DPE + || (ncm->skb_tx_data->len + + div + rem + skb->len + + ncm->skb_tx_ndp->len + ndp_align + (2 * dgram_idx_len)) + > max_size)) { + skb2 = package_for_tx(ncm); + if (!skb2) + goto err; + } +``` + +This issue is presently under investigation on the Linux kernel mailing +list, and you can find the entire discussion at [1]. + +[1] https://lore.kernel.org/all/20231204183751.64202-1-hiagofranco@gmail.com/ + +Upstream-Status: Inappropriate [other] + +There is no proper patch for now, so instead we're using this patch that +makes VNC work again as a temporarily solution until the mainline code +gets fixed. + +Related-to: TEI-1078 +Signed-off-by: Hiago De Franco <hiago.franco@toradex.com> +Signed-off-by: Joao Paulo Goncalves <joao.goncalves@toradex.com> +--- + drivers/usb/gadget/function/f_ncm.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/drivers/usb/gadget/function/f_ncm.c b/drivers/usb/gadget/function/f_ncm.c +index e0c183234283..5e972d1c1a0c 100644 +--- a/drivers/usb/gadget/function/f_ncm.c ++++ b/drivers/usb/gadget/function/f_ncm.c +@@ -113,7 +113,7 @@ static inline unsigned ncm_bitrate(struct usb_gadget *g) + * Smaller packets are not likely to be trying to maximize the + * throughput and will be mstly sending smaller infrequent frames. + */ +-#define TX_MAX_NUM_DPE 32 ++#define TX_MAX_NUM_DPE 4 + + /* Delay for the transmit to wait before sending an unfilled NTB frame. */ + #define TX_TIMEOUT_NSECS 300000 +-- +2.34.1 + diff --git a/recipes-kernel/linux/linux-toradex-upstream_mainline.bb b/recipes-kernel/linux/linux-toradex-upstream_mainline.bb index 6a962ed..5212cac 100644 --- a/recipes-kernel/linux/linux-toradex-upstream_mainline.bb +++ b/recipes-kernel/linux/linux-toradex-upstream_mainline.bb @@ -11,9 +11,10 @@ TDX_PATCHES = " \ file://0002-Revert-drm-panel-simple-drop-use-of-data-mapping-pro.patch \ file://0003-drivers-chipidea-disable-runtime-pm-for-imx6ul.patch \ file://0004-media-i2c-ov5640-Implement-get_mbus_config.patch \ + file://0001-usb-gadget-f_ncm-Apply-workaround-for-packet-cloggin.patch \ " # set PV manually, that way PREFERRED_VERSION can be set to a constant value PV = "mainline" -LINUX_VERSION = "6.6-rc" +LINUX_VERSION = "6.8-rc" KBRANCH = "master" SRCREV_machine = "${AUTOREV}" |