Revert "ath9k: export HW random number generator"

This reverts commit 274f981cc891be4c2732d9e3d0024dc7ac0e8ee7. Oleksij Rempel
noticed that the randomness doesn't look to be good enough and Stephan Mueller
commented:

"I would say that the discussed RNG does not seem fit for hooking it up with the
hwrandom framework."

http://lkml.kernel.org/g/3945775.m5HblJPgiO@tauon.atsec.com

So let's the revert the patch until we are sure that we can trust this random
generator.

Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

diff --git a/drivers/net/wireless/ath/ath9k/Kconfig b/drivers/net/wireless/ath/ath9k/Kconfig
index bde62ec98bc7fdda37f996b350adde78e31e8f77..fee0cadb0f5ed592fba313f1040b2e1f5ed1ebde 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/Kconfig
+++ b/drivers/net/wireless/ath/ath9k/Kconfig
@@ -176,10 +176,3 @@ config ATH9K_HTC_DEBUGFS
        depends on ATH9K_HTC && DEBUG_FS
        ---help---
          Say Y, if you need access to ath9k_htc's statistics.
-
-config ATH9K_HWRNG
-       bool "Random number generator support"
-       depends on ATH9K && (HW_RANDOM = y || HW_RANDOM = ATH9K)
-       default y
-       ---help---
-         Provides a hardware random number generator to the kernel.

diff --git a/drivers/net/wireless/ath/ath9k/Makefile b/drivers/net/wireless/ath/ath9k/Makefile
index 76f9dc37500b18f70e4de8516b3ecb98ef24b511..ecda613c2d547d4278ac0665c8c0eeaaf594c66a 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/Makefile
+++ b/drivers/net/wireless/ath/ath9k/Makefile
@@ -15,7 +15,6 @@ ath9k-$(CONFIG_ATH9K_DFS_DEBUGFS) += dfs_debug.o
 ath9k-$(CONFIG_ATH9K_DFS_CERTIFIED) += dfs.o
 ath9k-$(CONFIG_ATH9K_TX99) += tx99.o
 ath9k-$(CONFIG_ATH9K_WOW) += wow.o
-ath9k-$(CONFIG_ATH9K_HWRNG) += rng.o
 
 ath9k-$(CONFIG_ATH9K_DEBUGFS) += debug.o
 

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 45596e5ae4db38a9084c9aaeadecd418f13551f9..a7a81b3969cec7e79b2cb73959c4d8ff1fb7489e 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -23,7 +23,6 @@
 #include <linux/leds.h>
 #include <linux/completion.h>
 #include <linux/time.h>
-#include <linux/hw_random.h>
 
 #include "common.h"
 #include "debug.h"
@@ -1042,12 +1041,6 @@ struct ath_softc {
        u32 wow_intr_before_sleep;
        bool force_wow;
 #endif
-
-#ifdef CONFIG_ATH9K_HWRNG
-       struct hwrng rng;
-       bool rng_initialized;
-       u32 rng_last;
-#endif
 };
 
 /********/
@@ -1070,22 +1063,6 @@ static inline int ath9k_tx99_send(struct ath_softc *sc,
 }
 #endif /* CONFIG_ATH9K_TX99 */
 
-/***************************/
-/* Random Number Generator */
-/***************************/
-#ifdef CONFIG_ATH9K_HWRNG
-void ath9k_rng_register(struct ath_softc *sc);
-void ath9k_rng_unregister(struct ath_softc *sc);
-#else
-static inline void ath9k_rng_register(struct ath_softc *sc)
-{
-}
-
-static inline void ath9k_rng_unregister(struct ath_softc *sc)
-{
-}
-#endif
-
 static inline void ath_read_cachesize(struct ath_common *common, int *csz)
 {
        common->bus_ops->read_cachesize(common, csz);

diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 5916ab2f4a3de9b34d4ab83225e4338741025d9e..cfd45cb8ccfc13df856bb4bbe07d8e2bef21228f 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -739,8 +739,6 @@ static int ath9k_start(struct ieee80211_hw *hw)
 
        ath9k_ps_restore(sc);
 
-       ath9k_rng_register(sc);
-
        return 0;
 }
 
@@ -830,8 +828,6 @@ static void ath9k_stop(struct ieee80211_hw *hw)
 
        ath9k_deinit_channel_context(sc);
 
-       ath9k_rng_unregister(sc);
-
        mutex_lock(&sc->mutex);
 
        ath_cancel_work(sc);

diff --git a/drivers/net/wireless/ath/ath9k/rng.c b/drivers/net/wireless/ath/ath9k/rng.c
deleted file mode 100644 (file)
index d8fa7a5..0000000
--- a/drivers/net/wireless/ath/ath9k/rng.c
+++ /dev/null
@@ -1,75 +0,0 @@
-/*
- * Copyright (c) 2015 Qualcomm Atheros, Inc.
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
-
-#include "ath9k.h"
-#include "hw.h"
-#include "ar9003_phy.h"
-
-static int ath9k_rng_data_read(struct hwrng *rng, u32 *data)
-{
-       u32 v1, v2;
-       struct ath_softc *sc = (struct ath_softc *)rng->priv;
-       struct ath_hw *ah = sc->sc_ah;
-
-       ath9k_ps_wakeup(sc);
-
-       REG_RMW_FIELD(ah, AR_PHY_TEST, AR_PHY_TEST_BBB_OBS_SEL, 5);
-       REG_CLR_BIT(ah, AR_PHY_TEST, AR_PHY_TEST_RX_OBS_SEL_BIT5);
-       REG_RMW_FIELD(ah, AR_PHY_TEST_CTL_STATUS, AR_PHY_TEST_CTL_RX_OBS_SEL, 0);
-
-       v1 = REG_READ(ah, AR_PHY_TST_ADC);
-       v2 = REG_READ(ah, AR_PHY_TST_ADC);
-
-       ath9k_ps_restore(sc);
-
-       /* wait for data ready */
-       if (v1 && v2 && sc->rng_last != v1 && v1 != v2) {
-               *data = (v1 & 0xffff) | (v2 << 16);
-               sc->rng_last = v2;
-
-               return sizeof(u32);
-       }
-
-       sc->rng_last = v2;
-
-       return 0;
-}
-
-void ath9k_rng_register(struct ath_softc *sc)
-{
-       struct ath_hw *ah = sc->sc_ah;
-
-       if (WARN_ON(sc->rng_initialized))
-               return;
-
-       if (!AR_SREV_9300_20_OR_LATER(ah))
-               return;
-
-       sc->rng.name = "ath9k";
-       sc->rng.data_read = ath9k_rng_data_read;
-       sc->rng.priv = (unsigned long)sc;
-
-       if (!hwrng_register(&sc->rng))
-               sc->rng_initialized = true;
-}
-
-void ath9k_rng_unregister(struct ath_softc *sc)
-{
-       if (sc->rng_initialized) {
-               hwrng_unregister(&sc->rng);
-               sc->rng_initialized = false;
-       }
-}