From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- Documentation/fb/s3fb.rst | 82 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 Documentation/fb/s3fb.rst (limited to 'Documentation/fb/s3fb.rst') diff --git a/Documentation/fb/s3fb.rst b/Documentation/fb/s3fb.rst new file mode 100644 index 000000000..e809d69c2 --- /dev/null +++ b/Documentation/fb/s3fb.rst @@ -0,0 +1,82 @@ +=========================================== +s3fb - fbdev driver for S3 Trio/Virge chips +=========================================== + + +Supported Hardware +================== + + S3 Trio32 + S3 Trio64 (and variants V+, UV+, V2/DX, V2/GX) + S3 Virge (and variants VX, DX, GX and GX2+) + S3 Plato/PX (completely untested) + S3 Aurora64V+ (completely untested) + + - only PCI bus supported + - only BIOS initialized VGA devices supported + - probably not working on big endian + +I tested s3fb on Trio64 (plain, V+ and V2/DX) and Virge (plain, VX, DX), +all on i386. + + +Supported Features +================== + + * 4 bpp pseudocolor modes (with 18bit palette, two variants) + * 8 bpp pseudocolor mode (with 18bit palette) + * 16 bpp truecolor modes (RGB 555 and RGB 565) + * 24 bpp truecolor mode (RGB 888) on (only on Virge VX) + * 32 bpp truecolor mode (RGB 888) on (not on Virge VX) + * text mode (activated by bpp = 0) + * interlaced mode variant (not available in text mode) + * doublescan mode variant (not available in text mode) + * panning in both directions + * suspend/resume support + * DPMS support + +Text mode is supported even in higher resolutions, but there is limitation to +lower pixclocks (maximum usually between 50-60 MHz, depending on specific +hardware, i get best results from plain S3 Trio32 card - about 75 MHz). This +limitation is not enforced by driver. Text mode supports 8bit wide fonts only +(hardware limitation) and 16bit tall fonts (driver limitation). Text mode +support is broken on S3 Trio64 V2/DX. + +There are two 4 bpp modes. First mode (selected if nonstd == 0) is mode with +packed pixels, high nibble first. Second mode (selected if nonstd == 1) is mode +with interleaved planes (1 byte interleave), MSB first. Both modes support +8bit wide fonts only (driver limitation). + +Suspend/resume works on systems that initialize video card during resume and +if device is active (for example used by fbcon). + + +Missing Features +================ +(alias TODO list) + + * secondary (not initialized by BIOS) device support + * big endian support + * Zorro bus support + * MMIO support + * 24 bpp mode support on more cards + * support for fontwidths != 8 in 4 bpp modes + * support for fontheight != 16 in text mode + * composite and external sync (is anyone able to test this?) + * hardware cursor + * video overlay support + * vsync synchronization + * feature connector support + * acceleration support (8514-like 2D, Virge 3D, busmaster transfers) + * better values for some magic registers (performance issues) + + +Known bugs +========== + + * cursor disable in text mode doesn't work + * text mode broken on S3 Trio64 V2/DX + + +-- +Ondrej Zajicek -- cgit v1.3.1