diff options
Diffstat (limited to 'gitlab/issues_text/target_missing/host_missing/accel_missing/1618')
| -rw-r--r-- | gitlab/issues_text/target_missing/host_missing/accel_missing/1618 | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/gitlab/issues_text/target_missing/host_missing/accel_missing/1618 b/gitlab/issues_text/target_missing/host_missing/accel_missing/1618 new file mode 100644 index 000000000..0ebb50b25 --- /dev/null +++ b/gitlab/issues_text/target_missing/host_missing/accel_missing/1618 @@ -0,0 +1,13 @@ +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: + |