From d94f9c55ff22397cc3436840437da533e9263716 Mon Sep 17 00:00:00 2001 From: Eric Lapuyade Date: Thu, 3 May 2012 16:33:32 +0200 Subject: [PATCH] NFC: nfc_targets_found() should accept zero target found The semantics for a zero target found event is that the polling operation could not complete. Signed-off-by: Eric Lapuyade Signed-off-by: Samuel Ortiz --- net/nfc/core.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/net/nfc/core.c b/net/nfc/core.c index 94ccf07374a5..749ee48d3600 100644 --- a/net/nfc/core.c +++ b/net/nfc/core.c @@ -560,6 +560,8 @@ EXPORT_SYMBOL(nfc_alloc_recv_skb); * The device driver must call this function when one or many nfc targets * are found. After calling this function, the device driver must stop * polling for targets. + * NOTE: This function can be called with targets=NULL and n_targets=0 to + * notify a driver error, meaning that the polling operation cannot complete. * IMPORTANT: this function must not be called from an atomic context. * In addition, it must also not be called from a context that would prevent * the NFC Core to call other nfc ops entry point concurrently. @@ -586,13 +588,18 @@ int nfc_targets_found(struct nfc_dev *dev, dev->targets_generation++; kfree(dev->targets); - dev->targets = kmemdup(targets, n_targets * sizeof(struct nfc_target), - GFP_ATOMIC); + dev->targets = NULL; - if (!dev->targets) { - dev->n_targets = 0; - device_unlock(&dev->dev); - return -ENOMEM; + if (targets) { + dev->targets = kmemdup(targets, + n_targets * sizeof(struct nfc_target), + GFP_ATOMIC); + + if (!dev->targets) { + dev->n_targets = 0; + device_unlock(&dev->dev); + return -ENOMEM; + } } dev->n_targets = n_targets;