[SeaBIOS] usb-msc.c: TEST_UNIT_READY needs USB_DIR_OUT?
Paolo Bonzini
pbonzini at redhat.com
Fri Mar 16 18:54:46 CET 2012
Il 15/03/2012 02:31, Kevin O'Connor ha scritto:
> 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 at 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 at 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);
The patch changes the way TEST_UNIT_READY is composed in the
buffers and breaks virtio-scsi. Now I remember why I did it
this way. :)
You can squash this in:
diff --git a/src/virtio-scsi.c b/src/virtio-scsi.c
index 76c5f29..d03a562 100644
--- a/src/virtio-scsi.c
+++ b/src/virtio-scsi.c
@@ -46,9 +46,8 @@ virtio_scsi_cmd(u16 ioaddr, struct vring_virtqueue *vq, struct disk_op_s *op,
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;
+ int in_num = (datain ? 2 : 1);
+ int out_num = (len ? 3 : 2) - in_num;
sg[0].addr = MAKE_FLATPTR(GET_SEG(SS), &req);
sg[0].length = sizeof(req);
@@ -56,8 +56,11 @@ virtio_scsi_cmd(u16 ioaddr, struct vring_virtqueue *vq, struct disk_op_s *op,
sg[out_num].addr = MAKE_FLATPTR(GET_SEG(SS), &resp);
sg[out_num].length = sizeof(resp);
- sg[data_idx].addr = op->buf_fl;
- sg[data_idx].length = len;
+ if (len) {
+ int data_idx = (datain ? 2 : 1);
+ sg[data_idx].addr = op->buf_fl;
+ sg[data_idx].length = len;
+ }
/* Add to virtqueue and kick host */
vring_add_buf(vq, sg, out_num, in_num, 0, 0);
and apply the patch.
Thanks!
Paolo
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