This is a note to let you know that I've just added the patch titled

iwlwifi: fix access to prph when transport is stopped

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: iwlwifi-fix-access-to-prph-when-transport-is-stopped.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Thu Feb 1 13:45:42 CET 2018

From: Sara Sharon sara.sharon@intel.com Date: Mon, 20 Nov 2017 13:25:05 +0200 Subject: iwlwifi: fix access to prph when transport is stopped

From: Sara Sharon sara.sharon@intel.com

[ Upstream commit 0232d2cd7aa8e1b810fe84fb4059a0bd1eabe2ba ]

When getting HW rfkill we get stop_device being called from two paths. One path is the IRQ calling stop device, and updating op mode and stack. As a result, cfg80211 is running rfkill sync work that shuts down all devices (second path). In the second path, we eventually get to iwl_mvm_stop_device which calls iwl_fw_dump_conf_clear->iwl_fw_dbg_stop_recording, that access periphery registers. The device may be stopped at this point from the first path, which will result with a failure to access those registers. Simply checking for the trans status is insufficient, since the race will still exist, only minimized. Instead, move the stop from iwl_fw_dump_conf_clear (which is getting called only from stop path) to the transport stop device function, where the access is always safe. This has the added value, of actually stopping dbgc before stopping device even when the stop is initiated from the transport.

Fixes: 1efc3843a4ee ("iwlwifi: stop dbgc recording before stopping DMA") Signed-off-by: Sara Sharon sara.sharon@intel.com Signed-off-by: Luca Coelho luciano.coelho@intel.com Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/wireless/intel/iwlwifi/fw/dbg.h | 2 -- drivers/net/wireless/intel/iwlwifi/pcie/trans-gen2.c | 6 ++++++ drivers/net/wireless/intel/iwlwifi/pcie/trans.c | 9 +++++++++ 3 files changed, 15 insertions(+), 2 deletions(-)

--- a/drivers/net/wireless/intel/iwlwifi/fw/dbg.h +++ b/drivers/net/wireless/intel/iwlwifi/fw/dbg.h @@ -209,8 +209,6 @@ static inline void iwl_fw_dbg_stop_recor

static inline void iwl_fw_dump_conf_clear(struct iwl_fw_runtime *fwrt) { - iwl_fw_dbg_stop_recording(fwrt); - fwrt->dump.conf = FW_DBG_INVALID; }

--- a/drivers/net/wireless/intel/iwlwifi/pcie/trans-gen2.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans-gen2.c @@ -49,6 +49,7 @@ * *****************************************************************************/ #include "iwl-trans.h" +#include "iwl-prph.h" #include "iwl-context-info.h" #include "internal.h"

@@ -156,6 +157,11 @@ void _iwl_trans_pcie_gen2_stop_device(st

trans_pcie->is_down = true;

+ /* Stop dbgc before stopping device */ + iwl_write_prph(trans, DBGC_IN_SAMPLE, 0); + udelay(100); + iwl_write_prph(trans, DBGC_OUT_CTRL, 0); + /* tell the device to stop sending interrupts */ iwl_disable_interrupts(trans);

--- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c @@ -1138,6 +1138,15 @@ static void _iwl_trans_pcie_stop_device(

trans_pcie->is_down = true;

+ /* Stop dbgc before stopping device */ + if (trans->cfg->device_family == IWL_DEVICE_FAMILY_7000) { + iwl_set_bits_prph(trans, MON_BUFF_SAMPLE_CTL, 0x100); + } else { + iwl_write_prph(trans, DBGC_IN_SAMPLE, 0); + udelay(100); + iwl_write_prph(trans, DBGC_OUT_CTRL, 0); + } + /* tell the device to stop sending interrupts */ iwl_disable_interrupts(trans);

Patches currently in stable-queue which might be from sara.sharon@intel.com are

queue-4.14/iwlwifi-fix-access-to-prph-when-transport-is-stopped.patch