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authorAvri Altman <avri.altman@wdc.com>2019-02-20 09:11:12 +0200
committerMartin K. Petersen <martin.petersen@oracle.com>2019-02-27 08:56:32 -0500
commit4eaa329e331343dd64996297583f2eee7d215e2a (patch)
tree7e6a2cffd23c310a9077ba89b295f90928688eb6 /Documentation/scsi/ufs.txt
parente9cb9655f84137c020496572ac6e43beafe0b4a7 (diff)
scsi: ufs-bsg: Change the calling convention for write descriptor
When we had a write descriptor query upiu, we appended the descriptor right after the bsg request. This was fine as the bsg driver allows to allocate whatever buffer we needed in its job request. Still, the proper way to deliver payload, however small (we only write config descriptors of 144 bytes), is by using the job request payload data buffer. So change this ABI now, while ufs-bsg is still new, and nobody is actually using it. Signed-off-by: Avri Altman <avri.altman@wdc.com> Reviewed-by: Evan Green <evgreen@chromium.org> Reviewed-by: Bean Huo <beanhuo@micron.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'Documentation/scsi/ufs.txt')
-rw-r--r--Documentation/scsi/ufs.txt6
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/scsi/ufs.txt b/Documentation/scsi/ufs.txt
index 520b5b033256..78fe7cbfae48 100644
--- a/Documentation/scsi/ufs.txt
+++ b/Documentation/scsi/ufs.txt
@@ -147,6 +147,12 @@ send SG_IO with the applicable sg_io_v4:
io_hdr_v4.max_response_len = reply_len;
io_hdr_v4.request_len = request_len;
io_hdr_v4.request = (__u64)request_upiu;
+ if (dir == SG_DXFER_TO_DEV) {
+ io_hdr_v4.dout_xfer_len = (uint32_t)byte_cnt;
+ io_hdr_v4.dout_xferp = (uintptr_t)(__u64)buff;
+ }
+
+If you wish to write a descriptor, use the dout_xferp sg_io_v4.
UFS Specifications can be found at,
UFS - http://www.jedec.org/sites/default/files/docs/JESD220.pdf