Messages in this thread | | | Date | Fri, 29 Sep 2023 10:48:47 -0700 | Subject | Re: [PATCH net] net: stmmac: dwmac-stm32: fix resume on STM32 MCU | From | Jacob Keller <> |
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On 9/27/2023 10:57 AM, Ben Wolsieffer wrote: > 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. >
Why not just keep clk_rx enabled unconditionally or unconditionally stop it during suspend? I guess that might be part of a larger cleanup and has more side effects?
> 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. >
I'd guess the follow-up refactor would target next?
> Fixes: 6528e02cc9ff ("net: ethernet: stmmac: add adaptation for stm32mp157c.") > Signed-off-by: Ben Wolsieffer <ben.wolsieffer@hefring.com> > ---
This seems pretty small and targeted so it does make sense to me as a net fix, but it definitely feels like a workaround.
I look forward to reading the cleanup patch mentioned.
Reviewed-by: Jacob Keller <jacob.e.keller@intel.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[] = {
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