| Message ID | 20211101233751.49222-3-jae.hyun.yoo@intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | Add LCLK control into Aspeed LPC sub drivers | expand |
On 11/2/21 00:37, jae.hyun.yoo@intel.com wrote: > From: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> > > If LPC BT driver is registered ahead of lpc-ctrl module, LPC BT > hardware block will be enabled without heart beating of LCLK until > lpc-ctrl enables the LCLK. This issue causes improper handling on > host interrupts when the host sends interrupts in that time frame. > Then kernel eventually forcibly disables the interrupt with > dumping stack and printing a 'nobody cared this irq' message out. > > To prevent this issue, all LPC sub drivers should enable LCLK > individually so this patch adds clock control logic into the LPC > BT driver. > > Fixes: 54f9c4d0778b ("ipmi: add an Aspeed BT IPMI BMC driver") > Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> LGTM, Reviewed-by: Cédric Le Goater <clg@kaod.org> Thanks, C. > --- > drivers/char/ipmi/bt-bmc.c | 24 +++++++++++++++++++++++- > 1 file changed, 23 insertions(+), 1 deletion(-) > > diff --git a/drivers/char/ipmi/bt-bmc.c b/drivers/char/ipmi/bt-bmc.c > index 7450904e330a..a20f92cc7b18 100644 > --- a/drivers/char/ipmi/bt-bmc.c > +++ b/drivers/char/ipmi/bt-bmc.c > @@ -5,6 +5,7 @@ > > #include <linux/atomic.h> > #include <linux/bt-bmc.h> > +#include <linux/clk.h> > #include <linux/errno.h> > #include <linux/interrupt.h> > #include <linux/io.h> > @@ -62,6 +63,7 @@ struct bt_bmc { > wait_queue_head_t queue; > struct timer_list poll_timer; > struct mutex mutex; > + struct clk *clk; > }; > > static atomic_t open_count = ATOMIC_INIT(0); > @@ -423,6 +425,19 @@ static int bt_bmc_probe(struct platform_device *pdev) > if (IS_ERR(bt_bmc->base)) > return PTR_ERR(bt_bmc->base); > > + bt_bmc->clk = devm_clk_get(dev, NULL); > + if (IS_ERR(bt_bmc->clk)) { > + rc = PTR_ERR(bt_bmc->clk); > + if (rc != -EPROBE_DEFER) > + dev_err(dev, "Unable to get clock\n"); > + return rc; > + } > + rc = clk_prepare_enable(bt_bmc->clk); > + if (rc) { > + dev_err(dev, "Unable to enable clock\n"); > + return rc; > + } > + > mutex_init(&bt_bmc->mutex); > init_waitqueue_head(&bt_bmc->queue); > > @@ -433,7 +448,7 @@ static int bt_bmc_probe(struct platform_device *pdev) > rc = misc_register(&bt_bmc->miscdev); > if (rc) { > dev_err(dev, "Unable to register misc device\n"); > - return rc; > + goto err; > } > > bt_bmc_config_irq(bt_bmc, pdev); > @@ -457,6 +472,11 @@ static int bt_bmc_probe(struct platform_device *pdev) > clr_b_busy(bt_bmc); > > return 0; > + > +err: > + clk_disable_unprepare(bt_bmc->clk); > + > + return rc; > } > > static int bt_bmc_remove(struct platform_device *pdev) > @@ -466,6 +486,8 @@ static int bt_bmc_remove(struct platform_device *pdev) > misc_deregister(&bt_bmc->miscdev); > if (bt_bmc->irq < 0) > del_timer_sync(&bt_bmc->poll_timer); > + clk_disable_unprepare(bt_bmc->clk); > + > return 0; > } > >
> Reviewed-by: Cédric Le Goater <clg@kaod.org>
Thanks a lot Cédric!
On Tue, 2 Nov 2021, at 10:07, jae.hyun.yoo@intel.com wrote: > From: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> > > If LPC BT driver is registered ahead of lpc-ctrl module, LPC BT > hardware block will be enabled without heart beating of LCLK until > lpc-ctrl enables the LCLK. This issue causes improper handling on > host interrupts when the host sends interrupts in that time frame. > Then kernel eventually forcibly disables the interrupt with > dumping stack and printing a 'nobody cared this irq' message out. > > To prevent this issue, all LPC sub drivers should enable LCLK > individually so this patch adds clock control logic into the LPC > BT driver. > > Fixes: 54f9c4d0778b ("ipmi: add an Aspeed BT IPMI BMC driver") > Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
diff --git a/drivers/char/ipmi/bt-bmc.c b/drivers/char/ipmi/bt-bmc.c index 7450904e330a..a20f92cc7b18 100644 --- a/drivers/char/ipmi/bt-bmc.c +++ b/drivers/char/ipmi/bt-bmc.c @@ -5,6 +5,7 @@ #include <linux/atomic.h> #include <linux/bt-bmc.h> +#include <linux/clk.h> #include <linux/errno.h> #include <linux/interrupt.h> #include <linux/io.h> @@ -62,6 +63,7 @@ struct bt_bmc { wait_queue_head_t queue; struct timer_list poll_timer; struct mutex mutex; + struct clk *clk; }; static atomic_t open_count = ATOMIC_INIT(0); @@ -423,6 +425,19 @@ static int bt_bmc_probe(struct platform_device *pdev) if (IS_ERR(bt_bmc->base)) return PTR_ERR(bt_bmc->base); + bt_bmc->clk = devm_clk_get(dev, NULL); + if (IS_ERR(bt_bmc->clk)) { + rc = PTR_ERR(bt_bmc->clk); + if (rc != -EPROBE_DEFER) + dev_err(dev, "Unable to get clock\n"); + return rc; + } + rc = clk_prepare_enable(bt_bmc->clk); + if (rc) { + dev_err(dev, "Unable to enable clock\n"); + return rc; + } + mutex_init(&bt_bmc->mutex); init_waitqueue_head(&bt_bmc->queue); @@ -433,7 +448,7 @@ static int bt_bmc_probe(struct platform_device *pdev) rc = misc_register(&bt_bmc->miscdev); if (rc) { dev_err(dev, "Unable to register misc device\n"); - return rc; + goto err; } bt_bmc_config_irq(bt_bmc, pdev); @@ -457,6 +472,11 @@ static int bt_bmc_probe(struct platform_device *pdev) clr_b_busy(bt_bmc); return 0; + +err: + clk_disable_unprepare(bt_bmc->clk); + + return rc; } static int bt_bmc_remove(struct platform_device *pdev) @@ -466,6 +486,8 @@ static int bt_bmc_remove(struct platform_device *pdev) misc_deregister(&bt_bmc->miscdev); if (bt_bmc->irq < 0) del_timer_sync(&bt_bmc->poll_timer); + clk_disable_unprepare(bt_bmc->clk); + return 0; }