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From: Ben Wolsieffer <ben.wolsieffer@hefring.com>
To: linux-stm32@st-md-mailman.stormreply.com,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>,
	Jose Abreu <joabreu@synopsys.com>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	Christophe Roullier <christophe.roullier@st.com>,
	Ben Wolsieffer <ben.wolsieffer@hefring.com>
Subject: [PATCH net] net: stmmac: dwmac-stm32: fix resume on STM32 MCU
Date: Wed, 27 Sep 2023 13:57:49 -0400	[thread overview]
Message-ID: <20230927175749.1419774-1-ben.wolsieffer@hefring.com> (raw)

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: 6528e02cc9ff ("net: ethernet: stmmac: add adaptation for stm32mp157c.")
Signed-off-by: Ben Wolsieffer <ben.wolsieffer@hefring.com>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
index bdb4de59a672..28c8ca5fba6c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
@@ -105,6 +105,7 @@ 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)
@@ -122,7 +123,8 @@ 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);
@@ -514,7 +516,8 @@ 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[] = {
-- 
2.42.0


WARNING: multiple messages have this Message-ID (diff)
From: Ben Wolsieffer <ben.wolsieffer@hefring.com>
To: linux-stm32@st-md-mailman.stormreply.com,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>,
	Jose Abreu <joabreu@synopsys.com>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	Christophe Roullier <christophe.roullier@st.com>,
	Ben Wolsieffer <ben.wolsieffer@hefring.com>
Subject: [PATCH net] net: stmmac: dwmac-stm32: fix resume on STM32 MCU
Date: Wed, 27 Sep 2023 13:57:49 -0400	[thread overview]
Message-ID: <20230927175749.1419774-1-ben.wolsieffer@hefring.com> (raw)

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: 6528e02cc9ff ("net: ethernet: stmmac: add adaptation for stm32mp157c.")
Signed-off-by: Ben Wolsieffer <ben.wolsieffer@hefring.com>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
index bdb4de59a672..28c8ca5fba6c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
@@ -105,6 +105,7 @@ 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)
@@ -122,7 +123,8 @@ 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);
@@ -514,7 +516,8 @@ 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[] = {
-- 
2.42.0


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             reply	other threads:[~2023-09-27 17:58 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-27 17:57 Ben Wolsieffer [this message]
2023-09-27 17:57 ` [PATCH net] net: stmmac: dwmac-stm32: fix resume on STM32 MCU Ben Wolsieffer
2023-09-29 17:48 ` Jacob Keller
2023-09-29 17:48   ` Jacob Keller
2023-10-02 13:54   ` Ben Wolsieffer
2023-10-02 13:54     ` Ben Wolsieffer
2023-10-06 11:47     ` Alexandre TORGUE
2023-10-06 11:47       ` Alexandre TORGUE
2023-10-04 20:30 ` patchwork-bot+netdevbpf
2023-10-04 20:30   ` patchwork-bot+netdevbpf

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