2017-04-06 03:49:05

by Michał Mirosław

Subject: [PATCH v2] NFC: pn533: use constant off-stack buffer for sending acks

fix for WARN:

usb 3-2.4.1: NFC: Exchanging data failed (error 0x13)
llcp: nfc_llcp_recv: err -5
llcp: nfc_llcp_symm_timer: SYMM timeout
------------[ cut here ]------------
WARNING: CPU: 1 PID: 26397 at .../drivers/usb/core/hcd.c:1584 usb_hcd_map_urb_for_dma+0x370/0x550
transfer buffer not dma capable
[...]
Workqueue: events nfc_llcp_timeout_work [nfc]
Call Trace:
? dump_stack+0x46/0x5a
? __warn+0xb9/0xe0
? warn_slowpath_fmt+0x5a/0x80
? usb_hcd_map_urb_for_dma+0x370/0x550
? usb_hcd_submit_urb+0x2fb/0xa60
? dequeue_entity+0x3f2/0xc30
? pn533_usb_send_ack+0x5d/0x80 [pn533_usb]
? pn533_usb_abort_cmd+0x13/0x20 [pn533_usb]
? pn533_dep_link_down+0x32/0x70 [pn533]
? nfc_dep_link_down+0x87/0xd0 [nfc]
[...]
usb 3-2.4.1: NFC: Exchanging data failed (error 0x13)
llcp: nfc_llcp_recv: err -5
llcp: nfc_llcp_symm_timer: SYMM timeout

Signed-off-by: Michał Mirosław <[email protected]>
---
v2:
- "un-moved" other declarations
- rebased against nfc-next
---
drivers/nfc/pn533/i2c.c | 2 +-
drivers/nfc/pn533/usb.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/nfc/pn533/i2c.c b/drivers/nfc/pn533/i2c.c
index 2c2fb9cfe10a..8f60ce039b0d 100644
--- a/drivers/nfc/pn533/i2c.c
+++ b/drivers/nfc/pn533/i2c.c
@@ -51,7 +51,7 @@ static int pn533_i2c_send_ack(struct pn533 *dev, gfp_t flags)
{
struct pn533_i2c_phy *phy = dev->phy;
struct i2c_client *client = phy->i2c_dev;
- u8 ack[6] = {0x00, 0x00, 0xff, 0x00, 0xff, 0x00};
+ static const u8 ack[6] = {0x00, 0x00, 0xff, 0x00, 0xff, 0x00};
/* spec 6.2.1.3: Preamble, SoPC (2), ACK Code (2), Postamble */
int rc;

diff --git a/drivers/nfc/pn533/usb.c b/drivers/nfc/pn533/usb.c
index 000159ea9c5f..8ed203ea21ea 100644
--- a/drivers/nfc/pn533/usb.c
+++ b/drivers/nfc/pn533/usb.c
@@ -148,11 +148,11 @@ static int pn533_submit_urb_for_ack(struct pn533_usb_phy *phy, gfp_t flags)
static int pn533_usb_send_ack(struct pn533 *dev, gfp_t flags)
{
struct pn533_usb_phy *phy = dev->phy;
- u8 ack[6] = {0x00, 0x00, 0xff, 0x00, 0xff, 0x00};
+ static const u8 ack[6] = {0x00, 0x00, 0xff, 0x00, 0xff, 0x00};
/* spec 7.1.1.3: Preamble, SoPC (2), ACK Code (2), Postamble */
int rc;

- phy->out_urb->transfer_buffer = ack;
+ phy->out_urb->transfer_buffer = (u8 *)ack;
phy->out_urb->transfer_buffer_length = sizeof(ack);
rc = usb_submit_urb(phy->out_urb, flags);

--
2.11.0

2017-04-16 22:37:42

by Samuel Ortiz

Subject: Re: [PATCH v2] NFC: pn533: use constant off-stack buffer for sending acks

Hi Michał,

On Thu, Apr 06, 2017 at 05:49:02AM +0200, Michał Mirosław wrote:
> fix for WARN:
>
> usb 3-2.4.1: NFC: Exchanging data failed (error 0x13)
> llcp: nfc_llcp_recv: err -5
> llcp: nfc_llcp_symm_timer: SYMM timeout
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 26397 at .../drivers/usb/core/hcd.c:1584 usb_hcd_map_urb_for_dma+0x370/0x550
> transfer buffer not dma capable
> [...]
> Workqueue: events nfc_llcp_timeout_work [nfc]
> Call Trace:
> ? dump_stack+0x46/0x5a
> ? __warn+0xb9/0xe0
> ? warn_slowpath_fmt+0x5a/0x80
> ? usb_hcd_map_urb_for_dma+0x370/0x550
> ? usb_hcd_submit_urb+0x2fb/0xa60
> ? dequeue_entity+0x3f2/0xc30
> ? pn533_usb_send_ack+0x5d/0x80 [pn533_usb]
> ? pn533_usb_abort_cmd+0x13/0x20 [pn533_usb]
> ? pn533_dep_link_down+0x32/0x70 [pn533]
> ? nfc_dep_link_down+0x87/0xd0 [nfc]
> [...]
> usb 3-2.4.1: NFC: Exchanging data failed (error 0x13)
> llcp: nfc_llcp_recv: err -5
> llcp: nfc_llcp_symm_timer: SYMM timeout
>
> Signed-off-by: Michał Mirosław <[email protected]>
> ---
> v2:
> - "un-moved" other declarations
> - rebased against nfc-next
> ---
> drivers/nfc/pn533/i2c.c | 2 +-
> drivers/nfc/pn533/usb.c | 4 ++--
> 2 files changed, 3 insertions(+), 3 deletions(-)
Applied to nfc-next, thanks.

Cheers,
Samuel.