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authorHaojie Li <lihaojie@kylinos.cn>2026-08-25 18:08:45 +0800
committerChun-Kuang Hu <chunkuang.hu@kernel.org>2026-09-28 23:20:55 +0000
commitbce7698e2e6565bb765bd0522337f29f5f312624 (patch)
tree0b735b7b4a27369cb4d75d9431b3ee59ce7e5bcc /Documentation/networking/x25.rst
downloadlinux-stable-bce7698e2e6565bb765bd0522337f29f5f312624.tar.gz
linux-stable-bce7698e2e6565bb765bd0522337f29f5f312624.zip
drm/mediatek: Add missing IS_ERR check for ovl_adaptor platform devicegrafted
platform_device_register_data() can fail and return an ERR_PTR, but the return value is used without checking, leading to an invalid pointer being stored in ddp_comp[].dev and passed to component_match_add() and mtk_ddp_comp_init(), which could result in a kernel crash. Add an IS_ERR() check to jump to the error handling path on failure. Fixes: 0d9eee9118b7 ("drm/mediatek: Add drm ovl_adaptor sub driver for MT8195") Cc: stable@vger.kernel.org Signed-off-by: Haojie Li <lihaojie@kylinos.cn> Reviewed-by: CK Hu <ck.hu@mediatek.com> Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260825100845.438893-1-lihaojie@kylinos.cn/ Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
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+.. SPDX-License-Identifier: GPL-2.0
+
+==================
+Linux X.25 Project
+==================
+
+As my third year dissertation at University I have taken it upon myself to
+write an X.25 implementation for Linux. My aim is to provide a complete X.25
+Packet Layer and a LAPB module to allow for "normal" X.25 to be run using
+Linux. There are two sorts of X.25 cards available, intelligent ones that
+implement LAPB on the card itself, and unintelligent ones that simply do
+framing, bit-stuffing and checksumming. These both need to be handled by the
+system.
+
+I therefore decided to write the implementation such that as far as the
+Packet Layer is concerned, the link layer was being performed by a lower
+layer of the Linux kernel and therefore it did not concern itself with
+implementation of LAPB. Therefore the LAPB modules would be called by
+unintelligent X.25 card drivers and not by intelligent ones, this would
+provide a uniform device driver interface, and simplify configuration.
+
+To confuse matters a little, an 802.2 LLC implementation is also possible
+which could allow X.25 to be run over an Ethernet (or Token Ring) and
+conform with the JNT "Pink Book", this would have a different interface to
+the Packet Layer but there would be no confusion since the class of device
+being served by the LLC would be completely separate from LAPB.
+
+Just when you thought that it could not become more confusing, another
+option appeared, XOT. This allows X.25 Packet Layer frames to operate over
+the Internet using TCP/IP as a reliable link layer. RFC1613 specifies the
+format and behaviour of the protocol. If time permits this option will also
+be actively considered.
+
+A linux-x25 mailing list has been created at vger.kernel.org to support the
+development and use of Linux X.25. It is early days yet, but interested
+parties are welcome to subscribe to it. Just send a message to
+majordomo@vger.kernel.org with the following in the message body:
+
+subscribe linux-x25
+end
+
+The contents of the Subject line are ignored.
+
+Jonathan
+
+g4klx@g4klx.demon.co.uk