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| author | Billy Tsai <billy_tsai@aspeedtech.com> | 2026-04-07 16:53:23 +0800 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2026-04-12 22:06:02 +0200 |
| commit | d35a6db887eeae7c57b719521e39d64f929c6dc3 (patch) | |
| tree | 1b85fbbe3994e83a074c46dde13e1024ae2b6aec /drivers/i3c | |
| parent | 0b73da96b6eb6b9354654f96a9d423ab22cb222d (diff) | |
| download | linux-next-d35a6db887eeae7c57b719521e39d64f929c6dc3.tar.gz linux-next-d35a6db887eeae7c57b719521e39d64f929c6dc3.zip | |
i3c: mipi-i3c-hci: fix IBI payload length calculation for final status
In DMA mode, the IBI status descriptor encodes the payload using
CHUNKS (number of chunks) and DATA_LENGTH (valid bytes in the last
chunk). All preceding chunks are implicitly full-sized.
The current code accumulates full chunk sizes for non-final status
descriptors, but for the final status descriptor it only adds
DATA_LENGTH. This ignores the contribution of the preceding full
chunks described by the same final status entry.
As a result, the computed IBI payload length is truncated whenever
the final status spans multiple chunks. For example, with a chunk
size of 4 bytes, CHUNKS=2 and DATA_LENGTH=1 should result in a total
payload size of 5 bytes, but the current code reports only 1 byte.
Fix the calculation by adding the size of (CHUNKS - 1) full chunks
plus DATA_LENGTH for the last chunk.
Fixes: 9ad9a52cce28 ("i3c/master: introduce the mipi-i3c-hci driver")
Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260407-i3c-hci-dma-v2-1-a583187b9d22@aspeedtech.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers/i3c')
| -rw-r--r-- | drivers/i3c/master/mipi-i3c-hci/dma.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c index e487ef52f6b4..e4daaa612055 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dma.c +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c @@ -754,7 +754,10 @@ static void hci_dma_process_ibi(struct i3c_hci *hci, struct hci_rh_data *rh) if (!(ibi_status & IBI_LAST_STATUS)) { ibi_size += chunks * rh->ibi_chunk_sz; } else { - ibi_size += FIELD_GET(IBI_DATA_LENGTH, ibi_status); + if (chunks) { + ibi_size += (chunks - 1) * rh->ibi_chunk_sz; + ibi_size += FIELD_GET(IBI_DATA_LENGTH, ibi_status); + } last_ptr = ptr; break; } |