diff options
Diffstat (limited to 'drivers/usb/storage/protocol.c')
| -rw-r--r-- | drivers/usb/storage/protocol.c | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/drivers/usb/storage/protocol.c b/drivers/usb/storage/protocol.c index 9ad30428d2d..cc8f7c52c72 100644 --- a/drivers/usb/storage/protocol.c +++ b/drivers/usb/storage/protocol.c @@ -157,7 +157,7 @@ void usb_stor_transparent_scsi_command(struct scsi_cmnd *srb, * pick up from where this one left off. */ unsigned int usb_stor_access_xfer_buf(unsigned char *buffer, - unsigned int buflen, struct scsi_cmnd *srb, unsigned int *index, + unsigned int buflen, struct scsi_cmnd *srb, struct scatterlist **sgptr, unsigned int *offset, enum xfer_buf_dir dir) { unsigned int cnt; @@ -184,16 +184,17 @@ unsigned int usb_stor_access_xfer_buf(unsigned char *buffer, * located in high memory -- then kmap() will map it to a temporary * position in the kernel's virtual address space. */ } else { - struct scatterlist *sg = - (struct scatterlist *) srb->request_buffer - + *index; + struct scatterlist *sg = *sgptr; + + if (!sg) + sg = (struct scatterlist *) srb->request_buffer; /* This loop handles a single s-g list entry, which may * include multiple pages. Find the initial page structure * and the starting offset within the page, and update * the *offset and *index values for the next loop. */ cnt = 0; - while (cnt < buflen && *index < srb->use_sg) { + while (cnt < buflen) { struct page *page = sg->page + ((sg->offset + *offset) >> PAGE_SHIFT); unsigned int poff = @@ -209,8 +210,7 @@ unsigned int usb_stor_access_xfer_buf(unsigned char *buffer, /* Transfer continues to next s-g entry */ *offset = 0; - ++*index; - ++sg; + sg = sg_next(sg); } /* Transfer the data for all the pages in this @@ -234,6 +234,7 @@ unsigned int usb_stor_access_xfer_buf(unsigned char *buffer, sglen -= plen; } } + *sgptr = sg; } /* Return the amount actually transferred */ @@ -245,9 +246,10 @@ unsigned int usb_stor_access_xfer_buf(unsigned char *buffer, void usb_stor_set_xfer_buf(unsigned char *buffer, unsigned int buflen, struct scsi_cmnd *srb) { - unsigned int index = 0, offset = 0; + unsigned int offset = 0; + struct scatterlist *sg = NULL; - usb_stor_access_xfer_buf(buffer, buflen, srb, &index, &offset, + usb_stor_access_xfer_buf(buffer, buflen, srb, &sg, &offset, TO_XFER_BUF); if (buflen < srb->request_bufflen) srb->resid = srb->request_bufflen - buflen; |