| Message ID | 20211008003302.1461733-1-linux@roeck-us.net (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | Revert "watchdog: iTCO_wdt: Account for rebooting on second timeout" | expand |
On 08.10.21 02:33, Guenter Roeck wrote: > This reverts commit cb011044e34c ("watchdog: iTCO_wdt: Account for > rebooting on second timeout") and commit aec42642d91f ("watchdog: iTCO_wdt: > Fix detection of SMI-off case") since those patches cause a regression > on certain boards (https://bugzilla.kernel.org/show_bug.cgi?id=213809). > > While this revert may result in some boards to only reset after twice > the configured timeout value, that is still better than a watchdog reset > after half the configured value. > > Fixes: cb011044e34c ("watchdog: iTCO_wdt: Account for rebooting on second timeout") > Fixes: aec42642d91f ("watchdog: iTCO_wdt: Fix detection of SMI-off case") > Cc: Jan Kiszka <jan.kiszka@siemens.com> > Cc: Mantas Mikulėnas <grawity@gmail.com> > Reported-by: Javier S. Pedro <debbugs@javispedro.com> > Signed-off-by: Guenter Roeck <linux@roeck-us.net> > --- > drivers/watchdog/iTCO_wdt.c | 12 +++--------- > 1 file changed, 3 insertions(+), 9 deletions(-) > > diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c > index 643c6c2d0b72..ced2fc0deb8c 100644 > --- a/drivers/watchdog/iTCO_wdt.c > +++ b/drivers/watchdog/iTCO_wdt.c > @@ -71,8 +71,6 @@ > #define TCOBASE(p) ((p)->tco_res->start) > /* SMI Control and Enable Register */ > #define SMI_EN(p) ((p)->smi_res->start) > -#define TCO_EN (1 << 13) > -#define GBL_SMI_EN (1 << 0) > > #define TCO_RLD(p) (TCOBASE(p) + 0x00) /* TCO Timer Reload/Curr. Value */ > #define TCOv1_TMR(p) (TCOBASE(p) + 0x01) /* TCOv1 Timer Initial Value*/ > @@ -357,12 +355,8 @@ static int iTCO_wdt_set_timeout(struct watchdog_device *wd_dev, unsigned int t) > > tmrval = seconds_to_ticks(p, t); > > - /* > - * If TCO SMIs are off, the timer counts down twice before rebooting. > - * Otherwise, the BIOS generally reboots when the SMI triggers. > - */ > - if (p->smi_res && > - (inl(SMI_EN(p)) & (TCO_EN | GBL_SMI_EN)) != (TCO_EN | GBL_SMI_EN)) > + /* For TCO v1 the timer counts down twice before rebooting */ > + if (p->iTCO_version == 1) > tmrval /= 2; > > /* from the specs: */ > @@ -527,7 +521,7 @@ static int iTCO_wdt_probe(struct platform_device *pdev) > * Disables TCO logic generating an SMI# > */ > val32 = inl(SMI_EN(p)); > - val32 &= ~TCO_EN; /* Turn off SMI clearing watchdog */ > + val32 &= 0xffffdfff; /* Turn off SMI clearing watchdog */ > outl(val32, SMI_EN(p)); > } > > Sigh, how broken is this architecture of the iTCO? Agreed, this leaves no option then. BTW, the fact that we saw an inconsistency in read-back timeout indicates that there is still an issue for the remaining /= 2 case (means v1), but I'm loosing interest in fixing those issues, given how hard it is to test broadly without breaking users first. Jan
On 10/8/21 12:52 AM, Jan Kiszka wrote: > On 08.10.21 02:33, Guenter Roeck wrote: >> This reverts commit cb011044e34c ("watchdog: iTCO_wdt: Account for >> rebooting on second timeout") and commit aec42642d91f ("watchdog: iTCO_wdt: >> Fix detection of SMI-off case") since those patches cause a regression >> on certain boards (https://bugzilla.kernel.org/show_bug.cgi?id=213809). >> >> While this revert may result in some boards to only reset after twice >> the configured timeout value, that is still better than a watchdog reset >> after half the configured value. >> >> Fixes: cb011044e34c ("watchdog: iTCO_wdt: Account for rebooting on second timeout") >> Fixes: aec42642d91f ("watchdog: iTCO_wdt: Fix detection of SMI-off case") >> Cc: Jan Kiszka <jan.kiszka@siemens.com> >> Cc: Mantas Mikulėnas <grawity@gmail.com> >> Reported-by: Javier S. Pedro <debbugs@javispedro.com> >> Signed-off-by: Guenter Roeck <linux@roeck-us.net> >> --- >> drivers/watchdog/iTCO_wdt.c | 12 +++--------- >> 1 file changed, 3 insertions(+), 9 deletions(-) >> >> diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c >> index 643c6c2d0b72..ced2fc0deb8c 100644 >> --- a/drivers/watchdog/iTCO_wdt.c >> +++ b/drivers/watchdog/iTCO_wdt.c >> @@ -71,8 +71,6 @@ >> #define TCOBASE(p) ((p)->tco_res->start) >> /* SMI Control and Enable Register */ >> #define SMI_EN(p) ((p)->smi_res->start) >> -#define TCO_EN (1 << 13) >> -#define GBL_SMI_EN (1 << 0) >> >> #define TCO_RLD(p) (TCOBASE(p) + 0x00) /* TCO Timer Reload/Curr. Value */ >> #define TCOv1_TMR(p) (TCOBASE(p) + 0x01) /* TCOv1 Timer Initial Value*/ >> @@ -357,12 +355,8 @@ static int iTCO_wdt_set_timeout(struct watchdog_device *wd_dev, unsigned int t) >> >> tmrval = seconds_to_ticks(p, t); >> >> - /* >> - * If TCO SMIs are off, the timer counts down twice before rebooting. >> - * Otherwise, the BIOS generally reboots when the SMI triggers. >> - */ >> - if (p->smi_res && >> - (inl(SMI_EN(p)) & (TCO_EN | GBL_SMI_EN)) != (TCO_EN | GBL_SMI_EN)) >> + /* For TCO v1 the timer counts down twice before rebooting */ >> + if (p->iTCO_version == 1) >> tmrval /= 2; >> >> /* from the specs: */ >> @@ -527,7 +521,7 @@ static int iTCO_wdt_probe(struct platform_device *pdev) >> * Disables TCO logic generating an SMI# >> */ >> val32 = inl(SMI_EN(p)); >> - val32 &= ~TCO_EN; /* Turn off SMI clearing watchdog */ >> + val32 &= 0xffffdfff; /* Turn off SMI clearing watchdog */ >> outl(val32, SMI_EN(p)); >> } >> >> > > Sigh, how broken is this architecture of the iTCO? Agreed, this leaves > no option then. > > BTW, the fact that we saw an inconsistency in read-back timeout > indicates that there is still an issue for the remaining /= 2 case > (means v1), but I'm loosing interest in fixing those issues, given how > hard it is to test broadly without breaking users first. > Agreed. This is because the /=2 handling is only implemented in iTCO_wdt_set_timeout() without matching code in iTCO_wdt_get_timeleft(). I don't have hardware to test, so I am not going to touch that code myself. We can address that if/when someone reports the actual problem and has the ability to test a fix. Thanks, Guenter
Wim, On Thu, Oct 07, 2021 at 05:33:02PM -0700, Guenter Roeck wrote: > This reverts commit cb011044e34c ("watchdog: iTCO_wdt: Account for > rebooting on second timeout") and commit aec42642d91f ("watchdog: iTCO_wdt: > Fix detection of SMI-off case") since those patches cause a regression > on certain boards (https://bugzilla.kernel.org/show_bug.cgi?id=213809). > > While this revert may result in some boards to only reset after twice > the configured timeout value, that is still better than a watchdog reset > after half the configured value. > > Fixes: cb011044e34c ("watchdog: iTCO_wdt: Account for rebooting on second timeout") > Fixes: aec42642d91f ("watchdog: iTCO_wdt: Fix detection of SMI-off case") > Cc: Jan Kiszka <jan.kiszka@siemens.com> > Cc: Mantas Mikulėnas <grawity@gmail.com> > Reported-by: Javier S. Pedro <debbugs@javispedro.com> > Signed-off-by: Guenter Roeck <linux@roeck-us.net> Any chance you can send a pull request with this patch prior to the v5.15 release ? Thanks, Guenter
Hi Guenter, > On Thu, Oct 07, 2021 at 05:33:02PM -0700, Guenter Roeck wrote: > > This reverts commit cb011044e34c ("watchdog: iTCO_wdt: Account for > > rebooting on second timeout") and commit aec42642d91f ("watchdog: iTCO_wdt: > > Fix detection of SMI-off case") since those patches cause a regression > > on certain boards (https://bugzilla.kernel.org/show_bug.cgi?id=213809). > > > > While this revert may result in some boards to only reset after twice > > the configured timeout value, that is still better than a watchdog reset > > after half the configured value. > > > > Fixes: cb011044e34c ("watchdog: iTCO_wdt: Account for rebooting on second timeout") > > Fixes: aec42642d91f ("watchdog: iTCO_wdt: Fix detection of SMI-off case") > > Cc: Jan Kiszka <jan.kiszka@siemens.com> > > Cc: Mantas Mikulėnas <grawity@gmail.com> > > Reported-by: Javier S. Pedro <debbugs@javispedro.com> > > Signed-off-by: Guenter Roeck <linux@roeck-us.net> > > Any chance you can send a pull request with this patch prior to the v5.15 > release ? Will do it this evening. Kind regards, Wim.
diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c index 643c6c2d0b72..ced2fc0deb8c 100644 --- a/drivers/watchdog/iTCO_wdt.c +++ b/drivers/watchdog/iTCO_wdt.c @@ -71,8 +71,6 @@ #define TCOBASE(p) ((p)->tco_res->start) /* SMI Control and Enable Register */ #define SMI_EN(p) ((p)->smi_res->start) -#define TCO_EN (1 << 13) -#define GBL_SMI_EN (1 << 0) #define TCO_RLD(p) (TCOBASE(p) + 0x00) /* TCO Timer Reload/Curr. Value */ #define TCOv1_TMR(p) (TCOBASE(p) + 0x01) /* TCOv1 Timer Initial Value*/ @@ -357,12 +355,8 @@ static int iTCO_wdt_set_timeout(struct watchdog_device *wd_dev, unsigned int t) tmrval = seconds_to_ticks(p, t); - /* - * If TCO SMIs are off, the timer counts down twice before rebooting. - * Otherwise, the BIOS generally reboots when the SMI triggers. - */ - if (p->smi_res && - (inl(SMI_EN(p)) & (TCO_EN | GBL_SMI_EN)) != (TCO_EN | GBL_SMI_EN)) + /* For TCO v1 the timer counts down twice before rebooting */ + if (p->iTCO_version == 1) tmrval /= 2; /* from the specs: */ @@ -527,7 +521,7 @@ static int iTCO_wdt_probe(struct platform_device *pdev) * Disables TCO logic generating an SMI# */ val32 = inl(SMI_EN(p)); - val32 &= ~TCO_EN; /* Turn off SMI clearing watchdog */ + val32 &= 0xffffdfff; /* Turn off SMI clearing watchdog */ outl(val32, SMI_EN(p)); }
This reverts commit cb011044e34c ("watchdog: iTCO_wdt: Account for rebooting on second timeout") and commit aec42642d91f ("watchdog: iTCO_wdt: Fix detection of SMI-off case") since those patches cause a regression on certain boards (https://bugzilla.kernel.org/show_bug.cgi?id=213809). While this revert may result in some boards to only reset after twice the configured timeout value, that is still better than a watchdog reset after half the configured value. Fixes: cb011044e34c ("watchdog: iTCO_wdt: Account for rebooting on second timeout") Fixes: aec42642d91f ("watchdog: iTCO_wdt: Fix detection of SMI-off case") Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Mantas Mikulėnas <grawity@gmail.com> Reported-by: Javier S. Pedro <debbugs@javispedro.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> --- drivers/watchdog/iTCO_wdt.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-)