Date: Sun, 13 Jan 2008 14:58:21 GMT From: Hans Petter Selasky <hselasky@FreeBSD.org> To: Perforce Change Reviews <perforce@FreeBSD.org> Subject: PERFORCE change 133192 for review Message-ID: <200801131458.m0DEwLim022888@repoman.freebsd.org>
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http://perforce.freebsd.org/chv.cgi?CH=133192 Change 133192 by hselasky@hselasky_laptop001 on 2008/01/13 14:58:20 Important patch. Sometimes the BUS-DMA framework will not report all segments, even if the virtual memory we load is crossing a segment! Because BUS-DMA starts counting "maxsegsz" from the "aligned" memory location, and when align=1 byte we are in for trouble. I'm not sure sure if this is a bug in BUS-DMA. Solution: Manually extend the last segment. Affected files ... .. //depot/projects/usb/src/sys/dev/usb/usb_subr.c#86 edit Differences ... ==== //depot/projects/usb/src/sys/dev/usb/usb_subr.c#86 (text+ko) ==== @@ -2269,6 +2269,7 @@ struct usbd_page *pg; uint32_t rem; uint8_t owned; + uint8_t ext_seg; /* extend last segment */ pc = arg; xfer = pc->xfer; @@ -2297,6 +2298,12 @@ rem = segs->ds_addr & (USB_PAGE_SIZE - 1); pc->page_offset_buf = rem; pc->page_offset_end += rem; + if (nseg < ((pc->page_offset_end + + (USB_PAGE_SIZE - 1)) / USB_PAGE_SIZE)) { + ext_seg = 1; + } else { + ext_seg = 0; + } nseg--; while (nseg > 0) { @@ -2306,6 +2313,14 @@ pg->physaddr = segs->ds_addr & ~(USB_PAGE_SIZE - 1); } + /* + * XXX The segments we get from BUS-DMA are not aligned, + * XXX so we need to extend the last segment if we are + * XXX unaligned and cross the segment boundary! + */ + if (ext_seg) { + (pg + 1)->physaddr = pg->physaddr + USB_PAGE_SIZE; + } if (xfer) { owned = mtx_owned(xfer->priv_mtx); if (!owned) @@ -2572,6 +2587,7 @@ struct usbd_page *pg; uint32_t rem; uint8_t owned; + uint8_t ext_seg; /* extend last segment */ xfer = pc->xfer; @@ -2599,6 +2615,12 @@ rem = segs->ds_addr & (USB_PAGE_SIZE - 1); pc->page_offset_buf = rem; pc->page_offset_end += rem; + if (nseg < ((pc->page_offset_end + + (USB_PAGE_SIZE - 1)) / USB_PAGE_SIZE)) { + ext_seg = 1; + } else { + ext_seg = 0; + } nseg--; while (nseg > 0) { @@ -2608,6 +2630,14 @@ pg->physaddr = segs->ds_addr & ~(USB_PAGE_SIZE - 1); } + /* + * XXX The segments we get from BUS-DMA are not aligned, + * XXX so we need to extend the last segment if we are + * XXX unaligned and cross the segment boundary! + */ + if (ext_seg) { + (pg + 1)->physaddr = pg->physaddr + USB_PAGE_SIZE; + } if (xfer) { owned = mtx_owned(xfer->priv_mtx); if (!owned)
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