When A/UX configures the CDROM device it sends a truncated MODE SELECT request for page 1 (MODE_PAGE_R_W_ERROR) which is only 6 bytes in length rather than 10. This seems to be due to bug in Apple's code which calculates the CDB message length incorrectly.
According to [1] this truncated request is accepted on real hardware whereas in QEMU it generates an INVALID_PARAM_LEN sense code which causes A/UX to get stuck in a loop retrying the command in an attempt to succeed. Alter the mode page request length check so that truncated requests are allowed as per real hardware, adding a trace event to enable the condition to be detected. [1] https://68kmla.org/bb/index.php?threads/scsi2sd-project-anyone-interested.29040/page-7#post-316444 Signed-off-by: Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk> --- hw/scsi/scsi-disk.c | 2 +- hw/scsi/trace-events | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c index 71fdf132c1..c657e4f5da 100644 --- a/hw/scsi/scsi-disk.c +++ b/hw/scsi/scsi-disk.c @@ -1525,7 +1525,7 @@ static int mode_select_pages(SCSIDiskReq *r, uint8_t *p, int len, bool change) goto invalid_param; } if (page_len > len) { - goto invalid_param_len; + trace_scsi_disk_mode_select_page_truncated(page, page_len, len); } if (!change) { diff --git a/hw/scsi/trace-events b/hw/scsi/trace-events index e91b55a961..25eae9f307 100644 --- a/hw/scsi/trace-events +++ b/hw/scsi/trace-events @@ -339,6 +339,7 @@ scsi_disk_dma_command_READ(uint64_t lba, uint32_t len) "Read (sector %" PRId64 " scsi_disk_dma_command_WRITE(const char *cmd, uint64_t lba, int len) "Write %s(sector %" PRId64 ", count %u)" scsi_disk_new_request(uint32_t lun, uint32_t tag, const char *line) "Command: lun=%d tag=0x%x data=%s" scsi_disk_aio_sgio_command(uint32_t tag, uint8_t cmd, uint64_t lba, int len, uint32_t timeout) "disk aio sgio: tag=0x%x cmd=0x%x (sector %" PRId64 ", count %d) timeout=%u" +scsi_disk_mode_select_page_truncated(int page, int len, int page_len) "page %d expected length %d but received length %d" # scsi-generic.c scsi_generic_command_complete_noio(void *req, uint32_t tag, int statuc) "Command complete %p tag=0x%x status=%d" -- 2.20.1