From: Samuel Ortiz <sameo@linux.intel.com>
To: "John W. Linville" <linville@tuxdriver.com>
Cc: Lauro Ramos Venancio <lauro.venancio@openbossa.org>,
Aloisio Almeida Jr <aloisio.almeida@openbossa.org>,
Ilan Elias <ilane@ti.com>,
linux-wireless@vger.kernel.org, linux-nfc@lists.01.org,
Eric Lapuyade <eric.lapuyade@intel.com>,
Samuel Ortiz <sameo@linux.intel.com>
Subject: [PATCH 13/33] NFC: Error management documentation
Date: Fri, 6 Jul 2012 22:09:33 +0200 [thread overview]
Message-ID: <1341605393-32056-14-git-send-email-sameo@linux.intel.com> (raw)
In-Reply-To: <1341605393-32056-1-git-send-email-sameo@linux.intel.com>
From: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
---
Documentation/nfc/nfc-hci.txt | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)
diff --git a/Documentation/nfc/nfc-hci.txt b/Documentation/nfc/nfc-hci.txt
index 320f933..89a339c 100644
--- a/Documentation/nfc/nfc-hci.txt
+++ b/Documentation/nfc/nfc-hci.txt
@@ -178,3 +178,36 @@ ANY_GET_PARAMETER to the reader A gate to get information on the target
that was discovered).
Typically, such an event will be propagated to NFC Core from MSGRXWQ context.
+
+Error management
+----------------
+
+Errors that occur synchronously with the execution of an NFC Core request are
+simply returned as the execution result of the request. These are easy.
+
+Errors that occur asynchronously (e.g. in a background protocol handling thread)
+must be reported such that upper layers don't stay ignorant that something
+went wrong below and know that expected events will probably never happen.
+Handling of these errors is done as follows:
+
+- driver (pn544) fails to deliver an incoming frame: it stores the error such
+that any subsequent call to the driver will result in this error. Then it calls
+the standard nfc_shdlc_recv_frame() with a NULL argument to report the problem
+above. shdlc stores a EREMOTEIO sticky status, which will trigger SMW to
+report above in turn.
+
+- SMW is basically a background thread to handle incoming and outgoing shdlc
+frames. This thread will also check the shdlc sticky status and report to HCI
+when it discovers it is not able to run anymore because of an unrecoverable
+error that happened within shdlc or below. If the problem occurs during shdlc
+connection, the error is reported through the connect completion.
+
+- HCI: if an internal HCI error happens (frame is lost), or HCI is reported an
+error from a lower layer, HCI will either complete the currently executing
+command with that error, or notify NFC Core directly if no command is executing.
+
+- NFC Core: when NFC Core is notified of an error from below and polling is
+active, it will send a tag discovered event with an empty tag list to the user
+space to let it know that the poll operation will never be able to detect a tag.
+If polling is not active and the error was sticky, lower levels will return it
+at next invocation.
--
1.7.10
next prev parent reply other threads:[~2012-07-06 19:59 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-06 20:09 [PATCH 00/33] NFC updates for 3.6 Samuel Ortiz
2012-07-06 20:09 ` [PATCH 01/33] NFC: Prepare asynchronous error management for driver and shdlc Samuel Ortiz
2012-07-06 20:09 ` [PATCH 02/33] NFC: Removed addressed shdlc TODOs Samuel Ortiz
2012-07-06 20:09 ` [PATCH 03/33] NFC: Handle SHDLC RSET frames from an SHDLC connected chip Samuel Ortiz
2012-07-06 20:09 ` [PATCH 04/33] NFC: Remove an impossible HCI error case Samuel Ortiz
2012-07-06 20:09 ` [PATCH 05/33] NFC: Implement HCP reaggregation allocation " Samuel Ortiz
2012-07-06 20:09 ` [PATCH 06/33] NFC: Changed HCI cmd execution completion result to std linux errno Samuel Ortiz
2012-07-06 20:09 ` [PATCH 07/33] NFC: Driver failure API Samuel Ortiz
2012-07-06 20:09 ` [PATCH 08/33] NFC: Factorize HCI cmd completion Samuel Ortiz
2012-07-06 20:09 ` [PATCH 09/33] NFC: Implement HCI driver or internal error management Samuel Ortiz
2012-07-06 20:09 ` [PATCH 10/33] NFC: Core must test the device polling state inside the device lock Samuel Ortiz
2012-07-06 20:09 ` [PATCH 11/33] NFC: nfc_targets_found() should accept zero target found Samuel Ortiz
2012-07-06 20:09 ` [PATCH 12/33] NFC: nfc_driver_failure() implementation Samuel Ortiz
2012-07-06 20:09 ` Samuel Ortiz [this message]
2012-07-06 20:09 ` [PATCH 14/33] NFC: update PN544 HCI driver state when opened/closed Samuel Ortiz
2012-07-06 20:09 ` [PATCH 15/33] NFC: Allow HCI driver to pre-open pipes to some gates Samuel Ortiz
2012-07-06 20:09 ` [PATCH 16/33] NFC: Add modules alias for NFC sockets Samuel Ortiz
2012-07-06 20:09 ` [PATCH 17/33] NFC: Add netlink module alias for NFC Samuel Ortiz
2012-07-06 20:09 ` [PATCH 18/33] NFC: Update LLCP socket target index when getting a connection Samuel Ortiz
2012-07-06 20:09 ` [PATCH 19/33] NFC: Fix LLCP getname socket op Samuel Ortiz
2012-07-06 20:09 ` [PATCH 20/33] NFC: Build LLCP general bytes upon request Samuel Ortiz
2012-07-06 20:09 ` [PATCH 21/33] NFC: Close listening LLCP sockets when the device is gone Samuel Ortiz
2012-07-06 20:09 ` [PATCH 22/33] NFC: Release LLCP SAP when the owner is released Samuel Ortiz
2012-07-06 20:09 ` [PATCH 23/33] NFC: Forbid LLCP service name reusing Samuel Ortiz
2012-07-06 20:09 ` [PATCH 24/33] NFC: Forbid SSAP binding to a not well known LLCP service Samuel Ortiz
2012-07-06 20:09 ` [PATCH 25/33] NFC: LLCP late binding Samuel Ortiz
2012-07-06 20:09 ` [PATCH 26/33] NFC: Handle LLCP Disconnected Mode frames Samuel Ortiz
2012-07-06 20:09 ` [PATCH 27/33] NFC: Remove warning from nfc_llcp_local_put Samuel Ortiz
2012-07-06 20:09 ` [PATCH 28/33] NFC: Do not return EBUSY when stopping a poll that's already stopped Samuel Ortiz
2012-07-06 20:09 ` [PATCH 29/33] NFC: Dereference LLCP bind socket address after checking for it to be NULL Samuel Ortiz
2012-07-06 20:09 ` [PATCH 30/33] NFC: Add initial Sony RC-S360 support to pn533 Samuel Ortiz
2012-07-06 20:09 ` [PATCH 31/33] NFC: Use communicate thru only for PaSoRi when trying to read Felica tags Samuel Ortiz
2012-07-06 20:09 ` [PATCH 32/33] NFC: Add ISO 14443 type B protocol Samuel Ortiz
2012-07-06 20:09 ` [PATCH 33/33] NFC: Check for llcp_sock and its device from llcp_sock_getname Samuel Ortiz
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