hi_cma: synthesize fallback zone from default CMA when no mmz= passed#37
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widgetii merged 1 commit intohisilicon-hi3516cv500from May 7, 2026
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openhisilicon's V3.5 cma_allocator (in user-side open_osal.ko) calls
hisi_get_cma_zone("anonymous") to look up a CMA region registered via
the kernel cmdline `mmz=` early_param. On stock OpenIPC firmware where
the U-Boot bootargs were never customised, no `mmz=` is present,
hisi_get_cma_zone returns NULL, and the OSAL allocator fails to register
any zone. After OpenIPC/openhisilicon#73 propagated -ENODEV from the
empty-zone case, `insmod hi_osal.ko` started failing loud, and
load_hisilicon's `|| report_error` aborts the whole module load chain.
Existing hi3516av300 / hi3516cv500 / hi3516dv300 cameras that "worked
for years" stopped loading any vendor module after a sysupgrade.
Fix: when the named lookup misses, synthesize a single fallback zone
that points to the kernel's default CMA pool (set by
CONFIG_CMA_SIZE_MBYTES or `cma=` in cmdline). The fallback is one-shot
(cached in a static struct) so subsequent get-by-name calls reuse it.
Verified on hi3516av300_imx415 with default OpenIPC bootargs (no mmz=,
no cma=) and CONFIG_CMA_SIZE_MBYTES=256: all 37 OSDRV modules load,
IMX415 4K2K_30FPS init succuss, RTSP server on :554, HTTP /image.jpg
returns a valid 3840x2160 baseline JPEG. No bootargs change required.
Boards that DO put `mmz=anonymous,...` in bootargs keep their per-zone
intent (named lookup is still tried first).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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Summary
openhisilicon's V3.5 `cma_allocator` (in user-side `open_osal.ko`) calls
`hisi_get_cma_zone("anonymous")` to look up a CMA region registered via
the kernel cmdline `mmz=` early_param. On stock OpenIPC firmware where
the U-Boot bootargs were never customised, no `mmz=` is present,
`hisi_get_cma_zone` returns NULL, the OSAL allocator fails to register
any zone, and after OpenIPC/openhisilicon#73 propagated `-ENODEV` from
the empty-zone case, `insmod hi_osal.ko` started failing loud.
Existing hi3516av300 / hi3516cv500 / hi3516dv300 cameras that worked
for years stopped loading any vendor module after a sysupgrade.
Fix
When the named lookup misses, synthesize a single fallback zone that
points to the kernel's default CMA pool (set by `CONFIG_CMA_SIZE_MBYTES`
or `cma=` in cmdline). The fallback is one-shot (cached in a `static`
struct) so subsequent get-by-name calls reuse it.
Boards that DO put `mmz=anonymous,...` in bootargs keep their per-zone
intent — named lookup is still tried first.
Test plan (verified on hi3516av300_imx415)
With default OpenIPC bootargs (no mmz=, no cma=) and
`CONFIG_CMA_SIZE_MBYTES=256`:
baseline JPEG (368 KB)
Companion firmware-side change: openipc/firmware bumps
`CONFIG_CMA_SIZE_MBYTES` to 256 and disables `CONFIG_HIGHMEM` in the
cv500-family generic configs (av300/cv500/dv300). HIGHMEM=y created the
lowmem/highmem boundary at `0xb0000000` that broke any CMA region
spanning it; HIGHMEM=n matches what hi3516ev300 has shipped for years.
🤖 Generated with Claude Code