| Message ID | 20220225175320.11041-4-biju.das.jz@bp.renesas.com |
|---|---|
| State | New |
| Headers | show |
| Series | RZG2L_WDT Fixes and Improvements | expand |
On Fri, Feb 25, 2022 at 05:53:16PM +0000, Biju Das wrote: > This patch fixes the issue 'BUG: Invalid wait context' during restart() > callback by using clk_prepare_enable() instead of pm_runtime_get_sync() > for turning on the clocks during restart. > > This issue is noticed when testing with renesas_defconfig. > > [ 42.213802] reboot: Restarting system > [ 42.217860] > [ 42.219364] ============================= > [ 42.223368] [ BUG: Invalid wait context ] > [ 42.227372] 5.17.0-rc5-arm64-renesas-00002-g10393723e35e #522 Not tainted > [ 42.234153] ----------------------------- > [ 42.238155] systemd-shutdow/1 is trying to lock: > [ 42.242766] ffff00000a650828 (&genpd->mlock){+.+.}-{3:3}, at: genpd_lock_mtx+0x14/0x20 > [ 42.250709] other info that might help us debug this: > [ 42.255753] context-{4:4} > [ 42.258368] 2 locks held by systemd-shutdow/1: > [ 42.262806] #0: ffff80000944e1c8 (system_transition_mutex#2){+.+.}-{3:3}, at: __do_sys_reboot+0xd0/0x250 > [ 42.272388] #1: ffff8000094c4e40 (rcu_read_lock){....}-{1:2}, at: atomic_notifier_call_chain+0x0/0x150 > [ 42.281795] stack backtrace: > [ 42.284672] CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 5.17.0-rc5-arm64-renesas-00002-g10393723e35e #522 > [ 42.294577] Hardware name: Renesas SMARC EVK based on r9a07g044c2 (DT) > [ 42.301096] Call trace: > [ 42.303538] dump_backtrace+0xcc/0xd8 > [ 42.307203] show_stack+0x14/0x30 > [ 42.310517] dump_stack_lvl+0x88/0xb0 > [ 42.314180] dump_stack+0x14/0x2c > [ 42.317492] __lock_acquire+0x1b24/0x1b50 > [ 42.321502] lock_acquire+0x120/0x3a8 > [ 42.325162] __mutex_lock+0x84/0x8f8 > [ 42.328737] mutex_lock_nested+0x30/0x58 > [ 42.332658] genpd_lock_mtx+0x14/0x20 > [ 42.336319] genpd_runtime_resume+0xc4/0x228 > [ 42.340587] __rpm_callback+0x44/0x170 > [ 42.344337] rpm_callback+0x64/0x70 > [ 42.347824] rpm_resume+0x4e0/0x6b8 > [ 42.351310] __pm_runtime_resume+0x50/0x78 > [ 42.355404] rzg2l_wdt_restart+0x28/0x68 > [ 42.359329] watchdog_restart_notifier+0x1c/0x30 > [ 42.363943] atomic_notifier_call_chain+0x94/0x150 > [ 42.368732] do_kernel_restart+0x24/0x30 > [ 42.372652] machine_restart+0x44/0x70 > [ 42.376399] kernel_restart+0x3c/0x60 > [ 42.380058] __do_sys_reboot+0x228/0x250 > [ 42.383977] __arm64_sys_reboot+0x20/0x28 > [ 42.387983] invoke_syscall+0x40/0xf8 > > Fixes: 2cbc5cd0b55fa2 ("watchdog: Add Watchdog Timer driver for RZ/G2L") > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> > Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Guenter Roeck <linux@roeck-us.net> > --- > V4->V5: > * Added Rb tag from Geert. > * CC'ed Linux PM. > V4: > * New patch > --- > drivers/watchdog/rzg2l_wdt.c | 25 +++++++++++++------------ > 1 file changed, 13 insertions(+), 12 deletions(-) > > diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c > index 0fc73b8a9567..48dfe6e5e64f 100644 > --- a/drivers/watchdog/rzg2l_wdt.c > +++ b/drivers/watchdog/rzg2l_wdt.c > @@ -43,6 +43,8 @@ struct rzg2l_wdt_priv { > struct reset_control *rstc; > unsigned long osc_clk_rate; > unsigned long delay; > + struct clk *pclk; > + struct clk *osc_clk; > }; > > static void rzg2l_wdt_wait_delay(struct rzg2l_wdt_priv *priv) > @@ -118,7 +120,9 @@ static int rzg2l_wdt_restart(struct watchdog_device *wdev, > > /* Reset the module before we modify any register */ > reset_control_reset(priv->rstc); > - pm_runtime_get_sync(wdev->parent); > + > + clk_prepare_enable(priv->pclk); > + clk_prepare_enable(priv->osc_clk); > > /* smallest counter value to reboot soon */ > rzg2l_wdt_write(priv, WDTSET_COUNTER_VAL(1), WDTSET); > @@ -165,7 +169,6 @@ static int rzg2l_wdt_probe(struct platform_device *pdev) > struct device *dev = &pdev->dev; > struct rzg2l_wdt_priv *priv; > unsigned long pclk_rate; > - struct clk *wdt_clk; > int ret; > > priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > @@ -177,22 +180,20 @@ static int rzg2l_wdt_probe(struct platform_device *pdev) > return PTR_ERR(priv->base); > > /* Get watchdog main clock */ > - wdt_clk = clk_get(&pdev->dev, "oscclk"); > - if (IS_ERR(wdt_clk)) > - return dev_err_probe(&pdev->dev, PTR_ERR(wdt_clk), "no oscclk"); > + priv->osc_clk = devm_clk_get(&pdev->dev, "oscclk"); > + if (IS_ERR(priv->osc_clk)) > + return dev_err_probe(&pdev->dev, PTR_ERR(priv->osc_clk), "no oscclk"); > > - priv->osc_clk_rate = clk_get_rate(wdt_clk); > - clk_put(wdt_clk); > + priv->osc_clk_rate = clk_get_rate(priv->osc_clk); > if (!priv->osc_clk_rate) > return dev_err_probe(&pdev->dev, -EINVAL, "oscclk rate is 0"); > > /* Get Peripheral clock */ > - wdt_clk = clk_get(&pdev->dev, "pclk"); > - if (IS_ERR(wdt_clk)) > - return dev_err_probe(&pdev->dev, PTR_ERR(wdt_clk), "no pclk"); > + priv->pclk = devm_clk_get(&pdev->dev, "pclk"); > + if (IS_ERR(priv->pclk)) > + return dev_err_probe(&pdev->dev, PTR_ERR(priv->pclk), "no pclk"); > > - pclk_rate = clk_get_rate(wdt_clk); > - clk_put(wdt_clk); > + pclk_rate = clk_get_rate(priv->pclk); > if (!pclk_rate) > return dev_err_probe(&pdev->dev, -EINVAL, "pclk rate is 0"); > > -- > 2.17.1 >
diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c index 0fc73b8a9567..48dfe6e5e64f 100644 --- a/drivers/watchdog/rzg2l_wdt.c +++ b/drivers/watchdog/rzg2l_wdt.c @@ -43,6 +43,8 @@ struct rzg2l_wdt_priv { struct reset_control *rstc; unsigned long osc_clk_rate; unsigned long delay; + struct clk *pclk; + struct clk *osc_clk; }; static void rzg2l_wdt_wait_delay(struct rzg2l_wdt_priv *priv) @@ -118,7 +120,9 @@ static int rzg2l_wdt_restart(struct watchdog_device *wdev, /* Reset the module before we modify any register */ reset_control_reset(priv->rstc); - pm_runtime_get_sync(wdev->parent); + + clk_prepare_enable(priv->pclk); + clk_prepare_enable(priv->osc_clk); /* smallest counter value to reboot soon */ rzg2l_wdt_write(priv, WDTSET_COUNTER_VAL(1), WDTSET); @@ -165,7 +169,6 @@ static int rzg2l_wdt_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct rzg2l_wdt_priv *priv; unsigned long pclk_rate; - struct clk *wdt_clk; int ret; priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); @@ -177,22 +180,20 @@ static int rzg2l_wdt_probe(struct platform_device *pdev) return PTR_ERR(priv->base); /* Get watchdog main clock */ - wdt_clk = clk_get(&pdev->dev, "oscclk"); - if (IS_ERR(wdt_clk)) - return dev_err_probe(&pdev->dev, PTR_ERR(wdt_clk), "no oscclk"); + priv->osc_clk = devm_clk_get(&pdev->dev, "oscclk"); + if (IS_ERR(priv->osc_clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(priv->osc_clk), "no oscclk"); - priv->osc_clk_rate = clk_get_rate(wdt_clk); - clk_put(wdt_clk); + priv->osc_clk_rate = clk_get_rate(priv->osc_clk); if (!priv->osc_clk_rate) return dev_err_probe(&pdev->dev, -EINVAL, "oscclk rate is 0"); /* Get Peripheral clock */ - wdt_clk = clk_get(&pdev->dev, "pclk"); - if (IS_ERR(wdt_clk)) - return dev_err_probe(&pdev->dev, PTR_ERR(wdt_clk), "no pclk"); + priv->pclk = devm_clk_get(&pdev->dev, "pclk"); + if (IS_ERR(priv->pclk)) + return dev_err_probe(&pdev->dev, PTR_ERR(priv->pclk), "no pclk"); - pclk_rate = clk_get_rate(wdt_clk); - clk_put(wdt_clk); + pclk_rate = clk_get_rate(priv->pclk); if (!pclk_rate) return dev_err_probe(&pdev->dev, -EINVAL, "pclk rate is 0");
This patch fixes the issue 'BUG: Invalid wait context' during restart() callback by using clk_prepare_enable() instead of pm_runtime_get_sync() for turning on the clocks during restart. This issue is noticed when testing with renesas_defconfig. [ 42.213802] reboot: Restarting system [ 42.217860] [ 42.219364] ============================= [ 42.223368] [ BUG: Invalid wait context ] [ 42.227372] 5.17.0-rc5-arm64-renesas-00002-g10393723e35e #522 Not tainted [ 42.234153] ----------------------------- [ 42.238155] systemd-shutdow/1 is trying to lock: [ 42.242766] ffff00000a650828 (&genpd->mlock){+.+.}-{3:3}, at: genpd_lock_mtx+0x14/0x20 [ 42.250709] other info that might help us debug this: [ 42.255753] context-{4:4} [ 42.258368] 2 locks held by systemd-shutdow/1: [ 42.262806] #0: ffff80000944e1c8 (system_transition_mutex#2){+.+.}-{3:3}, at: __do_sys_reboot+0xd0/0x250 [ 42.272388] #1: ffff8000094c4e40 (rcu_read_lock){....}-{1:2}, at: atomic_notifier_call_chain+0x0/0x150 [ 42.281795] stack backtrace: [ 42.284672] CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 5.17.0-rc5-arm64-renesas-00002-g10393723e35e #522 [ 42.294577] Hardware name: Renesas SMARC EVK based on r9a07g044c2 (DT) [ 42.301096] Call trace: [ 42.303538] dump_backtrace+0xcc/0xd8 [ 42.307203] show_stack+0x14/0x30 [ 42.310517] dump_stack_lvl+0x88/0xb0 [ 42.314180] dump_stack+0x14/0x2c [ 42.317492] __lock_acquire+0x1b24/0x1b50 [ 42.321502] lock_acquire+0x120/0x3a8 [ 42.325162] __mutex_lock+0x84/0x8f8 [ 42.328737] mutex_lock_nested+0x30/0x58 [ 42.332658] genpd_lock_mtx+0x14/0x20 [ 42.336319] genpd_runtime_resume+0xc4/0x228 [ 42.340587] __rpm_callback+0x44/0x170 [ 42.344337] rpm_callback+0x64/0x70 [ 42.347824] rpm_resume+0x4e0/0x6b8 [ 42.351310] __pm_runtime_resume+0x50/0x78 [ 42.355404] rzg2l_wdt_restart+0x28/0x68 [ 42.359329] watchdog_restart_notifier+0x1c/0x30 [ 42.363943] atomic_notifier_call_chain+0x94/0x150 [ 42.368732] do_kernel_restart+0x24/0x30 [ 42.372652] machine_restart+0x44/0x70 [ 42.376399] kernel_restart+0x3c/0x60 [ 42.380058] __do_sys_reboot+0x228/0x250 [ 42.383977] __arm64_sys_reboot+0x20/0x28 [ 42.387983] invoke_syscall+0x40/0xf8 Fixes: 2cbc5cd0b55fa2 ("watchdog: Add Watchdog Timer driver for RZ/G2L") Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> --- V4->V5: * Added Rb tag from Geert. * CC'ed Linux PM. V4: * New patch --- drivers/watchdog/rzg2l_wdt.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-)