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authorClemens Ladisch <clemens@ladisch.de>2011-12-03 23:41:31 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2012-01-12 11:35:25 -0800
commit766b8a7f7ee006dfd73dbc676addd80f7dbe86ef (patch)
tree818c4c1709838ac321940e68624ec6d0228b9db1
parent0d5b25f934978301b2a1385c72f3b6abe04db484 (diff)
downloadlwn-766b8a7f7ee006dfd73dbc676addd80f7dbe86ef.tar.gz
lwn-766b8a7f7ee006dfd73dbc676addd80f7dbe86ef.zip
usb: fix number of mapped SG DMA entries
commit bc677d5b64644c399cd3db6a905453e611f402ab upstream. 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: <IRQ> [<ffffffff81036d3b>] warn_slowpath_common+0x80/0x98 [<ffffffff81036de7>] warn_slowpath_fmt+0x41/0x43 [<ffffffff811fa5ae>] check_unmap+0x4e4/0x695 [<ffffffff8105e92c>] ? trace_hardirqs_off+0xd/0xf [<ffffffff8147208b>] ? _raw_spin_unlock_irqrestore+0x33/0x50 [<ffffffff811fa84a>] debug_dma_unmap_sg+0xeb/0x117 [<ffffffff8137b02f>] usb_hcd_unmap_urb_for_dma+0x71/0x188 [<ffffffff8137b166>] unmap_urb_for_dma+0x20/0x22 [<ffffffff8137b1c5>] usb_hcd_giveback_urb+0x5d/0xc0 [<ffffffffa0000d02>] ehci_urb_done+0xf7/0x10c [ehci_hcd] [<ffffffffa0001140>] qh_completions+0x429/0x4bd [ehci_hcd] [<ffffffffa000340a>] ehci_work+0x95/0x9c0 [ehci_hcd] ... ---[ end trace f29ac88a5a48c580 ]--- Mapped at: [<ffffffff811faac4>] debug_dma_map_sg+0x45/0x139 [<ffffffff8137bc0b>] usb_hcd_map_urb_for_dma+0x22e/0x478 [<ffffffff8137c494>] usb_hcd_submit_urb+0x63f/0x6fa [<ffffffff8137d01c>] usb_submit_urb+0x2c7/0x2de [<ffffffff8137dcd4>] usb_sg_wait+0x55/0x161 Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/usb/core/hcd.c5
-rw-r--r--drivers/usb/host/ehci-q.c2
-rw-r--r--drivers/usb/host/uhci-q.c2
-rw-r--r--drivers/usb/host/whci/qset.c4
-rw-r--r--drivers/usb/host/xhci-ring.c4
-rw-r--r--include/linux/usb.h1
6 files changed, 9 insertions, 9 deletions
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 39ea00bfb9c4..691d212cac49 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1387,11 +1387,10 @@ 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 0917e3a32465..2499b3bce360 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -649,7 +649,7 @@ 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 84ed28b34f93..82539913ad84 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 a403b53e86b9..76083ae92138 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 b4b06910f684..c0c5d6c7cb69 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2570,7 +2570,7 @@ 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");
@@ -2754,7 +2754,7 @@ 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,
le16_to_cpu(urb->ep->desc.wMaxPacketSize));
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 73c7df489607..b08e04cf202b 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -1202,6 +1202,7 @@ 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 */