MS9132/MS9133 Linux Driver - Patches

Patches for the official MacroSilicon MS9132 USB-to-HDMI driver (v3.0.1.3) on Linux.

The official driver was written for kernel 6.1. On newer kernels it fails to compile or the display does not work at all. On any kernel, the driver floods the system log with unnecessary messages.

This software is provided "as is", without warranty of any kind. Use at your own risk. This is an unofficial community patch -- not supported by MacroSilicon.

Which patches do I need?

Your kernel	What to apply
6.1 (Debian 12)	Patch 6 only (recommended)
6.2 - 6.6	Patches 1, 5, 6
6.7 - 6.9	Patches 1, 3, 5, 6
6.10	Patches 1, 3, 4, 5, 6
6.11+ (Debian 13)	All patches (1-6)

Patches

#	What it fixes	Files	Kernel
1	Build error: missing vmalloc.h header	msdisp_drm_gem.c	6.2+
2	Build error: platform_driver.remove must return void	msdisp_plat_dev.c, .h, msdisp_drm_drv.h	6.11+
3	Build error: old EDID functions removed from kernel	msdisp_drm_connector.c, .h	6.7+
4	Display does not work: open("/dev/dri/card1") returns error	msdisp_drm_drv.c	6.10+
5	Build error: missing scatterlist.h header	usb_hal/usb_hal_thread.c	6.2+
6	Log spam: driver prints ~40 messages/sec to system log	msdisp_drm_fb.c	All

All patches use #if LINUX_VERSION_CODE guards and are safe to apply on any kernel version.

Patch details

Patch 1 - vmalloc.h (msdisp_drm_gem.c): Kernel 6.2 stopped including vmalloc.h indirectly. Without it, the driver fails to compile with undefined symbol errors.

Patch 2 - platform_driver.remove (msdisp_plat_dev.c, .h, msdisp_drm_drv.h): Kernel 6.11 changed the remove callback from returning int to returning void. Without this, the driver fails to compile.

Patch 3 - EDID API (msdisp_drm_connector.c, .h): Kernel 6.7 replaced the EDID functions (drm_do_get_edid, drm_connector_update_edid_property, etc.) with new ones. Without this, the driver fails to compile.

Patch 4 - FOP_UNSIGNED_OFFSET (msdisp_drm_drv.c): Kernel 6.10 requires the FOP_UNSIGNED_OFFSET flag in DRM file operations. Without it, the display device node cannot be opened and the display is completely unusable. All other symptoms (logind errors, missing xrandr outputs, empty EDID) are consequences of this.

Patch 5 - scatterlist.h (usb_hal/usb_hal_thread.c): Same as Patch 1 -- kernel 6.2 stopped including scatterlist.h indirectly.

Patch 6 - Log spam (msdisp_drm_fb.c): The driver logs a message every time a framebuffer is created (~40 times/sec). This floods dmesg, wastes CPU on printk spinlocks, and can worsen USB controller contention (see XHCI_CONTENTION.md). The fix changes dev_info to dev_dbg so the message is only visible when debug logging is enabled. Recommended for all kernels.

Repository Structure

patches/                     Individual patch files (apply to official source)
ms9132-debian12-patched/     Ready to compile on Debian 12 (kernel 6.1)
ms9132-debian13-patched/     Ready to compile on Debian 13 (kernel 6.11+)

Quick Start (pre-patched source)

If your system matches Debian 12 or 13, use the pre-patched source directly:

# Install build dependencies:
sudo apt install linux-headers-$(uname -r) build-essential

# Debian 12:
cd ms9132-debian12-patched
make clean && make

# Debian 13:
cd ms9132-debian13-patched
make clean && make

Then install:

sudo mkdir -p /lib/modules/$(uname -r)/extra
sudo cp drm/usbdisp_drm.ko drm/usbdisp_usb.ko /lib/modules/$(uname -r)/extra/
sudo depmod -a
sudo modprobe usbdisp_drm
sudo modprobe usbdisp_usb

Quick Start (apply patches manually)

For other kernels, get the official driver source (v3.0.1.3) from MacroSilicon and apply the patches you need:

# From the driver source root (where drm/ and usb_hal/ are):
cd drm
for p in /path/to/patches/msdisp_*.patch; do patch -p0 < "$p"; done
cd ../usb_hal
for p in /path/to/patches/usb_hal_*.patch; do patch -p0 < "$p"; done
cd ..
make clean && make

For the full guide (Secure Boot signing, autoloading, recompilation after kernel updates), see INSTALL.md.

Important Notes

• Do NOT create an X11 xorg.conf.d file for the USB display. X.org auto-detects it. Explicit configuration causes GDM to crash.
• glamor initialization failed on the USB display is normal -- it uses software rendering (ShadowFB).
• usb hal is null in dmesg when unplugging the adapter is expected.
• Cursor disappears when moving from the USB display to another monitor (Wayland/Mutter): the driver has no hardware cursor planes. See TROUBLESHOOTING.md for the fix.
• USB contention: On systems with a single USB controller, the video adapter can starve other USB devices (Bluetooth audio, webcams, etc.). See XHCI_CONTENTION.md.

Tested Environment

• Debian 12 (Bookworm), kernel 6.1.0-42-amd64 (Patch 6 only)
• Debian 13 (Trixie), kernel 6.12.69+deb13-amd64 (All patches)
• systemd 257, GDM, GNOME (X11 and Wayland)
• Secure Boot enabled (MOK signed modules)
• USB adapter: BLEWE generic USB 3.0 to HDMI (MS9132 chip, USB ID 534d:9132)

Related Projects

• ms912x - Reverse-engineered open source driver for MS912x chips

License

GPL v2, same as the original driver.