From bc677d5b64644c399cd3db6a905453e611f402ab Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Sat, 3 Dec 2011 23:41:31 +0100 Subject: [PATCH] usb: fix number of mapped SG DMA entries Add a new field num_mapped_sgs to struct urb so that we have a place to store the number of mapped entries and can also retain the original value of entries in num_sgs. Previously, usb_hcd_map_urb_for_dma() would overwrite this with the number of mapped entries, which would break dma_unmap_sg() because it requires the original number of entries. This fixes warnings like the following when using USB storage devices: ------------[ cut here ]------------ WARNING: at lib/dma-debug.c:902 check_unmap+0x4e4/0x695() ehci_hcd 0000:00:12.2: DMA-API: device driver frees DMA sg list with different entry count [map count=4] [unmap count=1] Modules linked in: ohci_hcd ehci_hcd Pid: 0, comm: kworker/0:1 Not tainted 3.2.0-rc2+ #319 Call Trace: [] warn_slowpath_common+0x80/0x98 [] warn_slowpath_fmt+0x41/0x43 [] check_unmap+0x4e4/0x695 [] ? trace_hardirqs_off+0xd/0xf [] ? _raw_spin_unlock_irqrestore+0x33/0x50 [] debug_dma_unmap_sg+0xeb/0x117 [] usb_hcd_unmap_urb_for_dma+0x71/0x188 [] unmap_urb_for_dma+0x20/0x22 [] usb_hcd_giveback_urb+0x5d/0xc0 [] ehci_urb_done+0xf7/0x10c [ehci_hcd] [] qh_completions+0x429/0x4bd [ehci_hcd] [] ehci_work+0x95/0x9c0 [ehci_hcd] ... ---[ end trace f29ac88a5a48c580 ]--- Mapped at: [] debug_dma_map_sg+0x45/0x139 [] usb_hcd_map_urb_for_dma+0x22e/0x478 [] usb_hcd_submit_urb+0x63f/0x6fa [] usb_submit_urb+0x2c7/0x2de [] usb_sg_wait+0x55/0x161 Signed-off-by: Clemens Ladisch Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hcd.c | 5 ++--- drivers/usb/host/ehci-q.c | 2 +- drivers/usb/host/uhci-q.c | 2 +- drivers/usb/host/whci/qset.c | 4 ++-- drivers/usb/host/xhci-ring.c | 4 ++-- include/linux/usb.h | 1 + 6 files changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 43a89e4ba928..2cec49d1773d 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -1398,11 +1398,10 @@ int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, ret = -EAGAIN; else urb->transfer_flags |= URB_DMA_MAP_SG; - if (n != urb->num_sgs) { - urb->num_sgs = n; + urb->num_mapped_sgs = n; + if (n != urb->num_sgs) urb->transfer_flags |= URB_DMA_SG_COMBINED; - } } else if (urb->sg) { struct scatterlist *sg = urb->sg; urb->transfer_dma = dma_map_page( diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c index f136f7f1c4f4..36ca5077cdf7 100644 --- a/drivers/usb/host/ehci-q.c +++ b/drivers/usb/host/ehci-q.c @@ -658,7 +658,7 @@ qh_urb_transaction ( /* * data transfer stage: buffer setup */ - i = urb->num_sgs; + i = urb->num_mapped_sgs; if (len > 0 && i > 0) { sg = urb->sg; buf = sg_dma_address(sg); diff --git a/drivers/usb/host/uhci-q.c b/drivers/usb/host/uhci-q.c index f6ca80ee4cec..d2c6f5ac4626 100644 --- a/drivers/usb/host/uhci-q.c +++ b/drivers/usb/host/uhci-q.c @@ -943,7 +943,7 @@ static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb, if (usb_pipein(urb->pipe)) status |= TD_CTRL_SPD; - i = urb->num_sgs; + i = urb->num_mapped_sgs; if (len > 0 && i > 0) { sg = urb->sg; data = sg_dma_address(sg); diff --git a/drivers/usb/host/whci/qset.c b/drivers/usb/host/whci/qset.c index d6e175428618..a91712c8bff5 100644 --- a/drivers/usb/host/whci/qset.c +++ b/drivers/usb/host/whci/qset.c @@ -443,7 +443,7 @@ static int qset_add_urb_sg(struct whc *whc, struct whc_qset *qset, struct urb *u remaining = urb->transfer_buffer_length; - for_each_sg(urb->sg, sg, urb->num_sgs, i) { + for_each_sg(urb->sg, sg, urb->num_mapped_sgs, i) { dma_addr_t dma_addr; size_t dma_remaining; dma_addr_t sp, ep; @@ -561,7 +561,7 @@ static int qset_add_urb_sg_linearize(struct whc *whc, struct whc_qset *qset, remaining = urb->transfer_buffer_length; - for_each_sg(urb->sg, sg, urb->num_sgs, i) { + for_each_sg(urb->sg, sg, urb->num_mapped_sgs, i) { size_t len; size_t sg_remaining; void *orig; diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 133ce302c860..d030f0b2bfa2 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2551,7 +2551,7 @@ static unsigned int count_sg_trbs_needed(struct xhci_hcd *xhci, struct urb *urb) struct scatterlist *sg; sg = NULL; - num_sgs = urb->num_sgs; + num_sgs = urb->num_mapped_sgs; temp = urb->transfer_buffer_length; xhci_dbg(xhci, "count sg list trbs: \n"); @@ -2735,7 +2735,7 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, return -EINVAL; num_trbs = count_sg_trbs_needed(xhci, urb); - num_sgs = urb->num_sgs; + num_sgs = urb->num_mapped_sgs; total_packet_count = roundup(urb->transfer_buffer_length, usb_endpoint_maxp(&urb->ep->desc)); diff --git a/include/linux/usb.h b/include/linux/usb.h index 2f05a7fa1ecf..4269c3f88148 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -1221,6 +1221,7 @@ struct urb { void *transfer_buffer; /* (in) associated data buffer */ dma_addr_t transfer_dma; /* (in) dma addr for transfer_buffer */ struct scatterlist *sg; /* (in) scatter gather buffer list */ + int num_mapped_sgs; /* (internal) mapped sg entries */ int num_sgs; /* (in) number of entries in the sg list */ u32 transfer_buffer_length; /* (in) data buffer length */ u32 actual_length; /* (return) actual transfer length */ -- GitLab