On Wed, Mar 14, 2012 at 01:02:39PM -0600, Steve Goodrich wrote:
I've been working with coreboot and SeaBIOS lately to try to get a platform working, including having boot capability using an SD-to-USB adapter. I got stuck on this last part: the USB/SD adapter would start enumeration, but would fail out during TEST_UNIT_READY because the device came back with a STALL (this via a LeCroy/CACT USB analyzer). I compared the transactions to those done during USB enumeration/configuration in Linux, and I noticed that the Direction bit in bmCBWFlags is *cleared* for the TEST_UNIT_READY command in Linux, but *set* in coreboot.
If Linux always clears the direction bit for zero length transfers, then I think it should be safe to do that in SeaBIOS also. How about the patch below?
-Kevin
From 1fd9a89082b807a4bb4ab6ce1285df474cb75746 Mon Sep 17 00:00:00 2001
From: Kevin O'Connor kevin@koconnor.net Date: Wed, 14 Mar 2012 21:27:45 -0400 Subject: [PATCH] Use OUT mode for all zero byte "scsi" transfers.
Some devices can get confused if asked to "read" data during a zero byte transfer, so consider these transfers as "writes". (Reported by Steve Goodrich.)
Also, extract out the code to determine the transfer direction into cdb_is_read().
Signed-off-by: Kevin O'Connor kevin@koconnor.net --- src/blockcmd.c | 7 +++++++ src/blockcmd.h | 1 + src/usb-msc.c | 4 ++-- src/virtio-scsi.c | 7 ++++--- 4 files changed, 14 insertions(+), 5 deletions(-)
diff --git a/src/blockcmd.c b/src/blockcmd.c index 8d881a5..2dda04d 100644 --- a/src/blockcmd.c +++ b/src/blockcmd.c @@ -35,6 +35,13 @@ cdb_cmd_data(struct disk_op_s *op, void *cdbcmd, u16 blocksize) } }
+// Determine if the command is a request to pull data from the device +int +cdb_is_read(u8 *cdbcmd, u16 blocksize) +{ + return blocksize && cdbcmd[0] != CDB_CMD_WRITE_10; +} + int scsi_is_ready(struct disk_op_s *op) { diff --git a/src/blockcmd.h b/src/blockcmd.h index ccfeeaf..8459d3e 100644 --- a/src/blockcmd.h +++ b/src/blockcmd.h @@ -100,6 +100,7 @@ struct cdbres_mode_sense_geom { } PACKED;
// blockcmd.c +int cdb_is_read(u8 *cdbcmd, u16 blocksize); int cdb_get_inquiry(struct disk_op_s *op, struct cdbres_inquiry *data); int cdb_get_sense(struct disk_op_s *op, struct cdbres_request_sense *data); int cdb_test_unit_ready(struct disk_op_s *op); diff --git a/src/usb-msc.c b/src/usb-msc.c index dadb9ca..c53a1f5 100644 --- a/src/usb-msc.c +++ b/src/usb-msc.c @@ -77,13 +77,13 @@ usb_cmd_data(struct disk_op_s *op, void *cdbcmd, u16 blocksize) cbw.dCBWSignature = CBW_SIGNATURE; cbw.dCBWTag = 999; // XXX cbw.dCBWDataTransferLength = bytes; - cbw.bmCBWFlags = (cbw.CBWCB[0] == CDB_CMD_WRITE_10) ? USB_DIR_OUT : USB_DIR_IN; + cbw.bmCBWFlags = cdb_is_read(cdbcmd, blocksize) ? USB_DIR_IN : USB_DIR_OUT; cbw.bCBWLUN = 0; // XXX cbw.bCBWCBLength = USB_CDB_SIZE;
// Transfer cbw to device. int ret = usb_msc_send(udrive_g, USB_DIR_OUT - , MAKE_FLATPTR(GET_SEG(SS), &cbw), sizeof(cbw)); + , MAKE_FLATPTR(GET_SEG(SS), &cbw), sizeof(cbw)); if (ret) goto fail;
diff --git a/src/virtio-scsi.c b/src/virtio-scsi.c index 3c59438..50339d7 100644 --- a/src/virtio-scsi.c +++ b/src/virtio-scsi.c @@ -31,7 +31,7 @@ struct virtio_lun_s {
static int virtio_scsi_cmd(u16 ioaddr, struct vring_virtqueue *vq, struct disk_op_s *op, - void *cdbcmd, u16 target, u16 lun, u32 len) + void *cdbcmd, u16 target, u16 lun, u16 blocksize) { struct virtio_scsi_req_cmd req; struct virtio_scsi_resp_cmd resp; @@ -44,7 +44,8 @@ virtio_scsi_cmd(u16 ioaddr, struct vring_virtqueue *vq, struct disk_op_s *op, req.lun[3] = (lun & 0xff); memcpy(req.cdb, cdbcmd, 16);
- int datain = (req.cdb[0] != CDB_CMD_WRITE_10); + u32 len = op->count * blocksize; + int datain = cdb_is_read(cdbcmd, blocksize); int data_idx = (datain ? 2 : 1); int out_num = (datain ? 1 : 2); int in_num = (len ? 3 : 2) - out_num; @@ -89,7 +90,7 @@ virtio_scsi_cmd_data(struct disk_op_s *op, void *cdbcmd, u16 blocksize) return virtio_scsi_cmd(GET_GLOBAL(vlun->ioaddr), GET_GLOBAL(vlun->vq), op, cdbcmd, GET_GLOBAL(vlun->target), GET_GLOBAL(vlun->lun), - blocksize * op->count); + blocksize); }
static int