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Use vmalloc() instead of kmalloc(..., GFP_DMA) to alloc the temporary buffer for firmware download blobs. This avoids the problem that a heavily fragmented system cannot allocate enough physically-contiguous memory for a large blob. The redundant alloc buffer mechanism was removed in commit900baa6e7b("firmware: cs_dsp: Remove redundant download buffer allocator"). While doing that I was overly focused on the possibility of the underlying bus requiring DMA-safe memory. So I used GFP_DMA kmalloc()s. I failed to notice that the code I was removing used vmalloc(). This creates a regression. Way back in 2014 the problem of fragmentation with kmalloc()s was fixed by commitcdcd7f7287("ASoC: wm_adsp: Use vmalloc to allocate firmware download buffer"). Although we don't need physically-contiguous memory, we don't know if the bus needs some particular alignment of the buffers. Since the change in 2014, the firmware download has always used whatever alignment vmalloc() returns. To avoid introducing a new problem, the temporary buffer is still used, to keep the same alignment of pointers passed to regmap_raw_write(). Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com> Fixes:900baa6e7b("firmware: cs_dsp: Remove redundant download buffer allocator") Link: https://patch.msgid.link/20260304141250.1578597-1-rf@opensource.cirrus.com Signed-off-by: Mark Brown <broonie@kernel.org>
Linux kernel ============ The Linux kernel is the core of any Linux operating system. It manages hardware, system resources, and provides the fundamental services for all other software. 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