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intel-hda: SD_STS different behavior for byte write vs. word write
Description of problem:
The Intel HDA SD_STS register is accessible two different ways in QEMU: either it's the top 8 bits of a 32-bit access
or it's directly accessible as a byte.
On reads, the register behavior for SD_STS is identical whether accessed as a 32-bit read or an 8-bit read.
On writes, the behavior is different; when written to as an 8-bit write, the BCIS, FIFOE, and DESE bits implement the documented HDA behavior of RW1C (writing a 1 to a bit clears it). When written to as the top 8 bits of a 32-bit write, writing a 1 to a bit sets the bit -- so an attempt to clear a status bit instead unconditionally sets the status bit.
Steps to reproduce:
1. Write 32 bits at SD_CTL address with bit 27 set (FIFOE). This should clear FIFOE, but does not.
2. Read back SD_STS (SD_CTL address + 3) as a byte. The FIFOE bit will be set.
3. Write 8 bits at SD_STS address with bit 3 set (FIFOE). This should clear FIFOE, and it does.
4. Read back SD_STS as a byte. The FIFOE bit will be cleared.
Additional information:
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