Additional finding: the workaround also works when applied at runtime,
without rebooting or changing the hardware request limit.

On Ubuntu 26.04 (kernel 7.0.0-30-generic), booted without additional
kernel parameters:

Before:
max_sectors_kb = 4096
max_hw_sectors_kb = 32767

Applied:
echo 1280 > /sys/block/sda/queue/max_sectors_kb

After:
max_sectors_kb = 1280
max_hw_sectors_kb = 32767 (unchanged)

The identical buffered fio test then completed successfully (16 GiB, no
I/O errors, no new SATA CRC errors).

Initially, the SATA link had downshifted to 1.5 Gb/s following the
previous failures. To exclude this as a contributing factor, I repeated
the test after a complete power cycle.

With the SATA link operating at its full 6.0 Gb/s speed, the runtime
workaround again passed:

16 GiB written in 68.5 seconds (239 MiB/s)

fio err=0

No kernel I/O errors

SMART UDMA_CRC_Error_Count unchanged (44 -> 44)

This confirms that reducing max_sectors_kb alone is sufficient to avoid
the observed failures under this workload, even at full SATA link speed.

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https://bugs.launchpad.net/bugs/2171415

Title:
  [Regression] Intel H97 SATA I/O errors and DMAR faults with kernel
  7.0, avoided by libata.force=max_sec=2560

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