Repository navigation
Detect whether the FIFOs are really enabled - #88
Merged
Merged
Conversation
phip1611
force-pushed
the
fifo-detection
branch
2 times, most recently
from
October 11, 2026 07:08
4d190b8 to
0069ab7
Compare
phip1611
marked this pull request as ready for review
October 11, 2026 07:08
phip1611
force-pushed
the
fifo-detection
branch
3 times, most recently
from
October 11, 2026 07:13
1d28ba1 to
8b50c15
Compare
Some 16550 UART datasheets call this register IIR, others ISR. Linux uses IIR. Mention both names, and let a docs search for IIR find it.
phip1611
force-pushed
the
fifo-detection
branch
2 times, most recently
from
October 11, 2026 07:30
c6ac616 to
097b6fd
Compare
send_bytes() trusted the config and wrote a whole FIFO's worth of data. On devices without working FIFO, e.g., a 16450, all but one byte got lost. Like Linux, check IIR bits 7:6 after configuring the FIFOs and fall back to one byte per write operation. The test backend now reports the FIFO state in the ISR, so tests can cover devices without FIFO.
phip1611
force-pushed
the
fifo-detection
branch
from
October 11, 2026 07:34
097b6fd to
d9b4f4f
Compare
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
send_bytes()trusted the config and wrote a whole FIFO's worth of data per THRE. On devices without working FIFO, e.g., a 16450, all but one byte got lost. Like Linux, check IIR bits 7:6 after configuring the FIFOs and fall back to one byte per THRE.Uart16550::fifo_enabled()reports the result;ISR::fifo_enabled()is a convenience getter for the FIFO bits.ISRmention its other name, IIR, which datasheets and Linux also use.🤖 Generated with Claude Code