[PATCH AUTOSEL 5.13 215/219] ath9k: fix sleeping in atomic context

Sasha Levin
2021-09-09T12:31:52Z

From: Miaoqing Pan <miaoqing@codeaurora.org>

[ 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@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1628481916-15030-1-git-send-email-miaoqing@codeaurora.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 2ca3b86714a9..172081ffe477 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1621,7 +1621,6 @@ 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);
}
}

@@ -2728,14 +2727,17 @@ 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