From 0529a7adf3421acf251355444a012073abaffebc Mon Sep 17 00:00:00 2001 From: "Mark A. Greer" Date: Wed, 2 Jul 2014 09:03:49 -0700 Subject: [PATCH] NFC: digital: Clear poll_tech_count before activating target Currently, digital_target_found() has a race between the events started by calling nfc_targets_found() (which ultimately expect ddev->poll_tech_count to be zero) and setting ddev->poll_tech_count to zero after the call to nfc_targets_found(). When the race is "lost" (i.e., ddev->poll_tech_count is found to not be zero by the events started by nfc_targets_found()), an error message is printed and the target is not found. A similar race exists when digital_tg_recv_atr_req() calls nfc_tm_activated(). Fix this by first saving the current value of ddev->poll_tech_count and then clearing it before calling nfc_targets_found()/nfc_tm_activated(). Clearing ddev->poll_tech_count before calling nfc_targets_found()/nfc_tm_activated() eliminates the race. Saving the value is required so it can be restored when nfc_targets_found()/nfc_tm_activated() fails and polling needs to continue. Acked-by: Thierry Escande Signed-off-by: Mark A. Greer Signed-off-by: Samuel Ortiz --- Reading git-format-patch failed