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Commit 7fbce1e4 authored by Ben Wolsieffer's avatar Ben Wolsieffer Committed by Greg Kroah-Hartman
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net: stmmac: dwmac-stm32: fix resume on STM32 MCU 



[ Upstream commit 6f195d6b0da3b689922ba9e302af2f49592fa9fc ]

The STM32MP1 keeps clk_rx enabled during suspend, and therefore the
driver does not enable the clock in stm32_dwmac_init() if the device was
suspended. The problem is that this same code runs on STM32 MCUs, which
do disable clk_rx during suspend, causing the clock to never be
re-enabled on resume.

This patch adds a variant flag to indicate that clk_rx remains enabled
during suspend, and uses this to decide whether to enable the clock in
stm32_dwmac_init() if the device was suspended.

This approach fixes this specific bug with limited opportunity for
unintended side-effects, but I have a follow up patch that will refactor
the clock configuration and hopefully make it less error prone.

Fixes: 6528e02c ("net: ethernet: stmmac: add adaptation for stm32mp157c.")
Signed-off-by: default avatarBen Wolsieffer <ben.wolsieffer@hefring.com>
Reviewed-by: default avatarJacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/20230927175749.1419774-1-ben.wolsieffer@hefring.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent f110aa37

drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c

+5 −2
Original line number Diff line number Diff line
@@ -111,6 +111,7 @@ struct stm32_ops { 
	int (*parse_data)(struct stm32_dwmac *dwmac,

			  struct device *dev);

	u32 syscfg_eth_mask;

	bool clk_rx_enable_in_suspend;

};



static int stm32_dwmac_init(struct plat_stmmacenet_data *plat_dat)
@@ -128,7 +129,8 @@ static int stm32_dwmac_init(struct plat_stmmacenet_data *plat_dat) 
	if (ret)

		return ret;



	if (!dwmac->dev->power.is_suspended) {

	if (!dwmac->ops->clk_rx_enable_in_suspend ||

	    !dwmac->dev->power.is_suspended) {

		ret = clk_prepare_enable(dwmac->clk_rx);

		if (ret) {

			clk_disable_unprepare(dwmac->clk_tx);
@@ -508,7 +510,8 @@ static struct stm32_ops stm32mp1_dwmac_data = { 
	.suspend = stm32mp1_suspend,

	.resume = stm32mp1_resume,

	.parse_data = stm32mp1_parse_data,

	.syscfg_eth_mask = SYSCFG_MP1_ETH_MASK

	.syscfg_eth_mask = SYSCFG_MP1_ETH_MASK,

	.clk_rx_enable_in_suspend = true

};



static const struct of_device_id stm32_dwmac_match[] = {