iwlwifi: protect SRAM debugfs

commit 4fc79db178f0a0ede479b4713e00df2d106028b3 upstream.

If the device is not started, we can't read its
SRAM and attempting to do so will cause issues.
Protect the debugfs read.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
[bwh: Backported to 3.2:
 - Adjust context
 - Pass iwl_shared not iwl_priv pointer to iwl_is_ready_rf()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/net/wireless/iwlwifi/iwl-debugfs.c b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
index a1670e3..93e6179 100644 (file)
--- a/drivers/net/wireless/iwlwifi/iwl-debugfs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
@@ -232,6 +232,9 @@ static ssize_t iwl_dbgfs_sram_read(struct file *file,
        struct iwl_priv *priv = file->private_data;
        size_t bufsz;
 
+       if (!iwl_is_ready_rf(priv->shrd))
+               return -EAGAIN;
+
        /* default is to dump the entire data segment */
        if (!priv->dbgfs_sram_offset && !priv->dbgfs_sram_len) {
                priv->dbgfs_sram_offset = 0x800000;