From: Billy Tsai Date: Tue, 7 Apr 2026 08:53:23 +0000 (+0800) Subject: i3c: mipi-i3c-hci: fix IBI payload length calculation for final status X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=d35a6db887eeae7c57b719521e39d64f929c6dc3;p=thirdparty%2Fkernel%2Flinux.git 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 Reviewed-by: Frank Li Link: https://patch.msgid.link/20260407-i3c-hci-dma-v2-1-a583187b9d22@aspeedtech.com Signed-off-by: Alexandre Belloni --- 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; }