[3.11.y.z extended stable] Patch "iwlwifi: mvm: don't allow A band if SKU forbids it" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    iwlwifi: mvm: don't allow A band if SKU forbids it

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From ea8089e871352b6cdbb2a0db345a7809883a3e16 Mon Sep 17 00:00:00 2001
From: Emmanuel Grumbach <emmanuel.grumbach at intel.com>
Date: Thu, 5 Dec 2013 22:42:55 +0200
Subject: iwlwifi: mvm: don't allow A band if SKU forbids it

commit c512865446e6dd5b6e91e81187e75b734ad7cfc7 upstream.

The driver wasn't reading the NVM properly. While this
didn't lead to any issue until now, it seems that there
is an old version of the NVM in the wild.
In this version, the A band channels appear to be valid
but the SKU capabilities (another field of the NVM) says
that A band isn't supported at all.
With this specific version of the NVM, the driver would
think that A band is supported while the HW / firmware
don't. This leads to asserts.

Reviewed-by: Johannes Berg <johannes.berg at intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/wireless/iwlwifi/iwl-nvm-parse.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/wireless/iwlwifi/iwl-nvm-parse.c b/drivers/net/wireless/iwlwifi/iwl-nvm-parse.c
index acd2665..de3c827 100644
--- a/drivers/net/wireless/iwlwifi/iwl-nvm-parse.c
+++ b/drivers/net/wireless/iwlwifi/iwl-nvm-parse.c
@@ -181,6 +181,11 @@ static int iwl_init_channel_map(struct device *dev, const struct iwl_cfg *cfg,

 	for (ch_idx = 0; ch_idx < IWL_NUM_CHANNELS; ch_idx++) {
 		ch_flags = __le16_to_cpup(nvm_ch_flags + ch_idx);
+
+		if (ch_idx >= NUM_2GHZ_CHANNELS &&
+		    !data->sku_cap_band_52GHz_enable)
+			ch_flags &= ~NVM_CHANNEL_VALID;
+
 		if (!(ch_flags & NVM_CHANNEL_VALID)) {
 			IWL_DEBUG_EEPROM(dev,
 					 "Ch. %d Flags %x [%sGHz] - No traffic\n",
--
1.9.0