Conexant CX25821 PCIe video capture bridge
A PCI Express media bridge chip Conexant introduced in 2008 for PC-based video surveillance and DVR cards, handling multi-channel standard-definition video and audio capture and playback. It primarily showed up in security and broadcast capture boards through the early 2010s.
recommendation
Worth keeping but documenting its niche: the CX25821 is long out of the active product cycle (Conexant itself was absorbed in 2017 and the chip's surveillance-card market peaked over a decade ago), yet the driver still receives real upstream maintenance, including a resource-leak fix backported in early 2026. Until those legacy surveillance and DVR installs disappear, removal would be premature, but the file deserves a note flagging it as legacy hardware.
repository signals
sources
- lore.kernel.org
The driver still receives recent upstream maintenance; a cx25821 resource-leak fix was backported in February 2026.
- cateee.net
LKDDb identifies this as the Conexant cx25821 support driver for TV/capture cards and shows it still present in current kernel series.
- eetimes.com
CX25821 was introduced in 2008 as a PCIe media bridge aimed at PC-based video surveillance / DVR designs, indicating an old surveillance-capture market niche rather than modern mainstream hardware.
- en.wikipedia.org
Conexant as a standalone company was acquired in 2017, consistent with the chipset family being long out of its original active product era.
codex reasoning notes (technical)
Kernel source inspection via shell (`rg`, `sed`) shows a real PCIe media-bridge driver for Conexant CX25821. Lore evidence came from `lore_file_timeline` on `drivers/media/pci/cx25821/cx25821-core.c`, which showed activity through 2026 and the cited February 2026 fix URL; directory-level timeline returned no direct hits, and removal-oriented `lore_regex` probes timed out rather than producing removal evidence. Deployment evidence came from web search results: LKDDb for driver identity/current presence, EE Times for 2008 launch/market targeting, and Wikipedia for vendor lifecycle context. Recommendation is `keep-annotate` because the hardware appears commercially obsolete and likely limited to legacy surveillance/DVR installs, but upstream still sees nontrivial maintenance, so straight deprecation/removal is not yet well-supported.