[PATCH AUTOSEL 4.19 72/74] ath9k: fix sleeping in atomic context

[Sasha Levin]

From: Miaoqing Pan <miaoqing@xxxxxxxxxxxxxx>

[ Upstream commit 7c48662b9d56666219f526a71ace8c15e6e12f1f ]

The problem is that gpio_free() can sleep and the cfg_soc() can be
called with spinlocks held. One problematic call tree is:

--> ath_reset_internal() takes &sc->sc_pcu_lock spin lock
   --> ath9k_hw_reset()
      --> ath9k_hw_gpio_request_in()
         --> ath9k_hw_gpio_request()
            --> ath9k_hw_gpio_cfg_soc()

Remove gpio_free(), use error message instead, so we should make sure
there is no GPIO conflict.

Also remove ath9k_hw_gpio_free() from ath9k_hw_apply_gpio_override(),
as gpio_mask will never be set for SOC chips.

Signed-off-by: Miaoqing Pan <miaoqing@xxxxxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/1628481916-15030-1-git-send-email-miaoqing@xxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/wireless/ath/ath9k/hw.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index 9f438d8e59f2..daad9e7b17cf 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1622,7 +1622,6 @@ static void ath9k_hw_apply_gpio_override(struct ath_hw *ah)
 		ath9k_hw_gpio_request_out(ah, i, NULL,
 					  AR_GPIO_OUTPUT_MUX_AS_OUTPUT);
 		ath9k_hw_set_gpio(ah, i, !!(ah->gpio_val & BIT(i)));
-		ath9k_hw_gpio_free(ah, i);
 	}
 }
 
@@ -2729,14 +2728,17 @@ static void ath9k_hw_gpio_cfg_output_mux(struct ath_hw *ah, u32 gpio, u32 type)
 static void ath9k_hw_gpio_cfg_soc(struct ath_hw *ah, u32 gpio, bool out,
 				  const char *label)
 {
+	int err;
+
 	if (ah->caps.gpio_requested & BIT(gpio))
 		return;
 
-	/* may be requested by BSP, free anyway */
-	gpio_free(gpio);
-
-	if (gpio_request_one(gpio, out ? GPIOF_OUT_INIT_LOW : GPIOF_IN, label))
+	err = gpio_request_one(gpio, out ? GPIOF_OUT_INIT_LOW : GPIOF_IN, label);
+	if (err) {
+		ath_err(ath9k_hw_common(ah), "request GPIO%d failed:%d\n",
+			gpio, err);
 		return;
+	}
 
 	ah->caps.gpio_requested |= BIT(gpio);
 }
-- 
2.30.2