Messages in this thread Patch in this message | | | Date | Thu, 27 Jan 2022 01:31:05 +0800 | From | Jisheng Zhang <> | Subject | Re: [PATCH] net: stmmac: dwmac-sun8i: fix double disable and unprepare "stmmaceth" clk |
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On Thu, Jan 27, 2022 at 12:00:42AM +0800, Jisheng Zhang wrote: > On Wed, Jan 26, 2022 at 11:12:28PM +0800, Jisheng Zhang wrote: > > On Sun, Jan 23, 2022 at 01:43:37PM -0600, Samuel Holland wrote: > > > On 1/23/22 7:28 AM, Jisheng Zhang wrote: > > > > Fix warnings on Allwinner D1 platform: > > > > > > > > [ 1.604695] ------------[ cut here ]------------ > > > > [ 1.609328] bus-emac already disabled > > > > [ 1.613015] WARNING: CPU: 0 PID: 38 at drivers/clk/clk.c:952 clk_core_disable+0xcc/0xec > > > > [ 1.621039] CPU: 0 PID: 38 Comm: kworker/u2:1 Not tainted 5.14.0-rc4#1 > > > > [ 1.627653] Hardware name: Allwinner D1 NeZha (DT) > > > > [ 1.632443] Workqueue: events_unbound deferred_probe_work_func > > > > [ 1.638286] epc : clk_core_disable+0xcc/0xec > > > > [ 1.642561] ra : clk_core_disable+0xcc/0xec > > > > [ 1.646835] epc : ffffffff8023c2ec ra : ffffffff8023c2ec sp : ffffffd00411bb10 > > > > [ 1.654054] gp : ffffffff80ec9988 tp : ffffffe00143a800 t0 : ffffffff80ed6a6f > > > > [ 1.661272] t1 : ffffffff80ed6a60 t2 : 0000000000000000 s0 : ffffffe001509e00 > > > > [ 1.668489] s1 : 0000000000000001 a0 : 0000000000000019 a1 : ffffffff80e80bd8 > > > > [ 1.675707] a2 : 00000000ffffefff a3 : 00000000000000f4 a4 : 0000000000000002 > > > > [ 1.682924] a5 : 0000000000000001 a6 : 0000000000000030 a7 : 00000000028f5c29 > > > > [ 1.690141] s2 : 0000000000000800 s3 : ffffffe001375000 s4 : ffffffe01fdf7a80 > > > > [ 1.697358] s5 : ffffffe001375010 s6 : ffffffff8001fc10 s7 : ffffffffffffffff > > > > [ 1.704577] s8 : 0000000000000001 s9 : ffffffff80ecb248 s10: ffffffe001b80000 > > > > [ 1.711794] s11: ffffffe001b80760 t3 : 0000000000000062 t4 : ffffffffffffffff > > > > [ 1.719012] t5 : ffffffff80e0f6d8 t6 : ffffffd00411b8f0 > > > > [ 1.724321] status: 8000000201800100 badaddr: 0000000000000000 cause: 0000000000000003 > > > > [ 1.732233] [<ffffffff8023c2ec>] clk_core_disable+0xcc/0xec > > > > [ 1.737810] [<ffffffff80240430>] clk_disable+0x38/0x78 > > > > [ 1.742956] [<ffffffff8001fc0c>] worker_thread+0x1a8/0x4d8 > > > > [ 1.748451] [<ffffffff8031a500>] stmmac_remove_config_dt+0x1c/0x4c > > > > [ 1.754646] [<ffffffff8031c8ec>] sun8i_dwmac_probe+0x378/0x82c > > > > [ 1.760484] [<ffffffff8001fc0c>] worker_thread+0x1a8/0x4d8 > > > > [ 1.765975] [<ffffffff8029a6c8>] platform_probe+0x64/0xf0 > > > > [ 1.771382] [<ffffffff8029833c>] really_probe.part.0+0x8c/0x30c > > > > [ 1.777305] [<ffffffff8029865c>] __driver_probe_device+0xa0/0x148 > > > > [ 1.783402] [<ffffffff8029873c>] driver_probe_device+0x38/0x138 > > > > [ 1.789324] [<ffffffff802989cc>] __device_attach_driver+0xd0/0x170 > > > > [ 1.795508] [<ffffffff802988f8>] __driver_attach_async_helper+0xbc/0xc0 > > > > [ 1.802125] [<ffffffff802965ac>] bus_for_each_drv+0x68/0xb4 > > > > [ 1.807701] [<ffffffff80298d1c>] __device_attach+0xd8/0x184 > > > > [ 1.813277] [<ffffffff802967b0>] bus_probe_device+0x98/0xbc > > > > [ 1.818852] [<ffffffff80297904>] deferred_probe_work_func+0x90/0xd4 > > > > [ 1.825122] [<ffffffff8001f8b8>] process_one_work+0x1e4/0x390 > > > > [ 1.830872] [<ffffffff8001fd80>] worker_thread+0x31c/0x4d8 > > > > [ 1.836362] [<ffffffff80026bf4>] kthreadd+0x94/0x188 > > > > [ 1.841335] [<ffffffff80026bf4>] kthreadd+0x94/0x188 > > > > [ 1.846304] [<ffffffff8001fa60>] process_one_work+0x38c/0x390 > > > > [ 1.852054] [<ffffffff80026564>] kthread+0x124/0x160 > > > > [ 1.857021] [<ffffffff8002643c>] set_kthread_struct+0x5c/0x60 > > > > [ 1.862770] [<ffffffff80001f08>] ret_from_syscall_rejected+0x8/0xc > > > > [ 1.868956] ---[ end trace 8d5c6046255f84a0 ]--- > > > > [ 1.873675] ------------[ cut here ]------------ > > > > [ 1.878366] bus-emac already unprepared > > > > [ 1.882378] WARNING: CPU: 0 PID: 38 at drivers/clk/clk.c:810 clk_core_unprepare+0xe4/0x168 > > > > [ 1.890673] CPU: 0 PID: 38 Comm: kworker/u2:1 Tainted: G W 5.14.0-rc4 #1 > > > > [ 1.898674] Hardware name: Allwinner D1 NeZha (DT) > > > > [ 1.903464] Workqueue: events_unbound deferred_probe_work_func > > > > [ 1.909305] epc : clk_core_unprepare+0xe4/0x168 > > > > [ 1.913840] ra : clk_core_unprepare+0xe4/0x168 > > > > [ 1.918375] epc : ffffffff8023d6cc ra : ffffffff8023d6cc sp : ffffffd00411bb10 > > > > [ 1.925593] gp : ffffffff80ec9988 tp : ffffffe00143a800 t0 : 0000000000000002 > > > > [ 1.932811] t1 : ffffffe01f743be0 t2 : 0000000000000040 s0 : ffffffe001509e00 > > > > [ 1.940029] s1 : 0000000000000001 a0 : 000000000000001b a1 : ffffffe00143a800 > > > > [ 1.947246] a2 : 0000000000000000 a3 : 00000000000000f4 a4 : 0000000000000001 > > > > [ 1.954463] a5 : 0000000000000000 a6 : 0000000005fce2a5 a7 : 0000000000000001 > > > > [ 1.961680] s2 : 0000000000000800 s3 : ffffffff80afeb90 s4 : ffffffe01fdf7a80 > > > > [ 1.968898] s5 : ffffffe001375010 s6 : ffffffff8001fc10 s7 : ffffffffffffffff > > > > [ 1.976115] s8 : 0000000000000001 s9 : ffffffff80ecb248 s10: ffffffe001b80000 > > > > [ 1.983333] s11: ffffffe001b80760 t3 : ffffffff80b39120 t4 : 0000000000000001 > > > > [ 1.990550] t5 : 0000000000000000 t6 : ffffffe001600002 > > > > [ 1.995859] status: 8000000201800120 badaddr: 0000000000000000 cause: 0000000000000003 > > > > [ 2.003771] [<ffffffff8023d6cc>] clk_core_unprepare+0xe4/0x168 > > > > [ 2.009609] [<ffffffff802403a0>] clk_unprepare+0x24/0x3c > > > > [ 2.014929] [<ffffffff8031a508>] stmmac_remove_config_dt+0x24/0x4c > > > > [ 2.021125] [<ffffffff8031c8ec>] sun8i_dwmac_probe+0x378/0x82c > > > > [ 2.026965] [<ffffffff8001fc0c>] worker_thread+0x1a8/0x4d8 > > > > [ 2.032463] [<ffffffff8029a6c8>] platform_probe+0x64/0xf0 > > > > [ 2.037871] [<ffffffff8029833c>] really_probe.part.0+0x8c/0x30c > > > > [ 2.043795] [<ffffffff8029865c>] __driver_probe_device+0xa0/0x148 > > > > [ 2.049892] [<ffffffff8029873c>] driver_probe_device+0x38/0x138 > > > > [ 2.055815] [<ffffffff802989cc>] __device_attach_driver+0xd0/0x170 > > > > [ 2.061999] [<ffffffff802988f8>] __driver_attach_async_helper+0xbc/0xc0 > > > > [ 2.068616] [<ffffffff802965ac>] bus_for_each_drv+0x68/0xb4 > > > > [ 2.074193] [<ffffffff80298d1c>] __device_attach+0xd8/0x184 > > > > [ 2.079769] [<ffffffff802967b0>] bus_probe_device+0x98/0xbc > > > > [ 2.085345] [<ffffffff80297904>] deferred_probe_work_func+0x90/0xd4 > > > > [ 2.091616] [<ffffffff8001f8b8>] process_one_work+0x1e4/0x390 > > > > [ 2.097367] [<ffffffff8001fd80>] worker_thread+0x31c/0x4d8 > > > > [ 2.102858] [<ffffffff80026bf4>] kthreadd+0x94/0x188 > > > > [ 2.107830] [<ffffffff80026bf4>] kthreadd+0x94/0x188 > > > > [ 2.112800] [<ffffffff8001fa60>] process_one_work+0x38c/0x390 > > > > [ 2.118551] [<ffffffff80026564>] kthread+0x124/0x160 > > > > [ 2.123520] [<ffffffff8002643c>] set_kthread_struct+0x5c/0x60 > > > > [ 2.129268] [<ffffffff80001f08>] ret_from_syscall_rejected+0x8/0xc > > > > [ 2.135455] ---[ end trace 8d5c6046255f84a1 ]--- > > > > > > > > the dwmmac-sun8i driver will get the "stmmaceth" clk as tx_clk during > > > > driver initialization. If stmmac_dvr_probe() fails due to various > > > > reasons, sun8i_dwmac_exit() will disable and unprepare the "stmmaceth" > > > > clk, then stmmac_remove_config_dt() will disable and unprepare the > > > > clk again. > > > > > > This should still be balanced, because both stmmac_probe_config_dt and > > > sun8i_dwmac_init prepare/enable the clock, so the dwmac-sun8i glue layer calls > > > stmmac_dvr_probe with the clock having an enable count of 2. It looks like the > > > underlying issue is that commit 5ec55823438e ("net: stmmac: add clocks > > > management for gmac driver") introduces unbalanced runtime PM. > > > > I added some printk then retested, the problem is triggered as below: > > > > stmmac_probe_config_dt() enable the clk > > sun8i_dwmac_init() enble the clk again > > stmmac_dvr_probe() succeed, but it calls pm_runtime_put(), so rpm will > > disable the clk > > sun8i_dwmac_reset() fails due to various reason > > sun8i_dwmac_exit() disable the clk, this is fine > > stmmac_remove_config_dt() disable the clk again, so ccf complains. > > > > The key here is: whether we should let stmmac_dvr_probe() calls > > pm_runtime_put() or let stmmac users to determine whether we could > > let rpm go? > > If we keep current behavior: stmmac users need to take care > > the code after stmmac_dvr_probe, including error handling code path, > > if we touch access registers, we need to call pm_runtime_get_sync() > > firstly. > > > > Since the commit 5ec55823438e has been in for a long time, I'll submit > > a patch to follow this way. > > > > After reading the code and commit history, I found some users suffering > from the runtimepm issues, for example, dwmac-rk.c, so I changed my > idea. I think it's better to let stmmac users to call pm_runtime_put(): > > First of all, only the users know whether it's safe to finally > keep the mac runtime suspended after probe. > > Secondly, if the users need to do platform specific operations after > stmmac_dvr_probe(), especially needs to access some registers, we have > to resume the mac firstly. The error handling code path also needs to > take care of it. It looks a bit strange resume immediately resume the > mac after suspending it. > > Any suggestion is welcome. > > PS: Since this would partially revert commit 5ec55823438e, I add Joakim > into the email thread. > If we keep current behavior as is, and let stmmac users to take care necessary runtime resume before specific handling, we need similar patch as dwmac-sun8i below for all stmmac users, especially the error handling path:
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c index 09644ab0d87a..ef2acea3d036 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c @@ -16,6 +16,7 @@ #include <linux/of_net.h> #include <linux/phy.h> #include <linux/platform_device.h> +#include <linux/pm_runtime.h> #include <linux/regulator/consumer.h> #include <linux/regmap.h> #include <linux/stmmac.h> @@ -1254,6 +1255,7 @@ static int sun8i_dwmac_probe(struct platform_device *pdev) ndev = dev_get_drvdata(&pdev->dev); priv = netdev_priv(ndev); + pm_runtime_get_sync(&pdev->dev); /* The mux must be registered after parent MDIO * so after stmmac_dvr_probe() */ @@ -1272,12 +1274,15 @@ static int sun8i_dwmac_probe(struct platform_device *pdev) goto dwmac_remove; } + pm_runtime_put(&pdev->dev); + return 0; dwmac_mux: reset_control_put(gmac->rst_ephy); clk_put(gmac->ephy_clk); dwmac_remove: + pm_runtime_put_noidle(&pdev->dev); stmmac_dvr_remove(&pdev->dev); dwmac_exit: sun8i_dwmac_exit(pdev, gmac); diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 8ded4be08b00..2f9bd1eacb81 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -7133,6 +7133,10 @@ int stmmac_dvr_remove(struct device *dev) netdev_info(priv->dev, "%s: removing driver", __func__); + pm_runtime_get_sync(dev); + pm_runtime_disable(dev); + pm_runtime_put_noidle(dev); + stmmac_stop_all_dma(priv); stmmac_mac_set(priv, priv->ioaddr, false); netif_carrier_off(ndev); @@ -7151,8 +7155,6 @@ int stmmac_dvr_remove(struct device *dev) if (priv->plat->stmmac_rst) reset_control_assert(priv->plat->stmmac_rst); reset_control_assert(priv->plat->stmmac_ahb_rst); - pm_runtime_put(dev); - pm_runtime_disable(dev); if (priv->hw->pcs != STMMAC_PCS_TBI && priv->hw->pcs != STMMAC_PCS_RTBI) stmmac_mdio_unregister(ndev);
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