| Message ID | 20210126150241.10009-1-saiprakash.ranjan@codeaurora.org (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | watchdog: qcom: Remove incorrect usage of QCOM_WDT_ENABLE_IRQ | expand |
On 1/26/21 7:02 AM, Sai Prakash Ranjan wrote: > As per register documentation, QCOM_WDT_ENABLE_IRQ which is BIT(1) > of watchdog control register is wakeup interrupt enable bit and > not related to bark interrupt at all, BIT(0) is used for that. > So remove incorrect usage of this bit when supporting bark irq for > pre-timeout notification. Currently with this bit set and bark > interrupt specified, pre-timeout notification and/or watchdog > reset/bite does not occur. > > Fixes: 36375491a439 ("watchdog: qcom: support pre-timeout when the bark irq is available") > Cc: stable@vger.kernel.org > Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> Assuming that pretimeout _does_ work with this patch applied, Reviewed-by: Guenter Roeck <linux@roeck-us.net> > --- > > Reading the conversations from when qcom pre-timeout support was > added [1], Bjorn already had mentioned it was not right to touch this > bit, not sure which SoC the pre-timeout was tested on at that time, > but I have tested this on SDM845, SM8150, SC7180 and watchdog bark > and bite does not occur with enabling this bit with the bark irq > specified in DT. > > [1] https://lore.kernel.org/linux-watchdog/20190906174009.GC11938@tuxbook-pro/ > > --- > drivers/watchdog/qcom-wdt.c | 13 +------------ > 1 file changed, 1 insertion(+), 12 deletions(-) > > diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c > index 7cf0f2ec649b..e38a87ffe5f5 100644 > --- a/drivers/watchdog/qcom-wdt.c > +++ b/drivers/watchdog/qcom-wdt.c > @@ -22,7 +22,6 @@ enum wdt_reg { > }; > > #define QCOM_WDT_ENABLE BIT(0) > -#define QCOM_WDT_ENABLE_IRQ BIT(1) > > static const u32 reg_offset_data_apcs_tmr[] = { > [WDT_RST] = 0x38, > @@ -63,16 +62,6 @@ struct qcom_wdt *to_qcom_wdt(struct watchdog_device *wdd) > return container_of(wdd, struct qcom_wdt, wdd); > } > > -static inline int qcom_get_enable(struct watchdog_device *wdd) > -{ > - int enable = QCOM_WDT_ENABLE; > - > - if (wdd->pretimeout) > - enable |= QCOM_WDT_ENABLE_IRQ; > - > - return enable; > -} > - > static irqreturn_t qcom_wdt_isr(int irq, void *arg) > { > struct watchdog_device *wdd = arg; > @@ -91,7 +80,7 @@ static int qcom_wdt_start(struct watchdog_device *wdd) > writel(1, wdt_addr(wdt, WDT_RST)); > writel(bark * wdt->rate, wdt_addr(wdt, WDT_BARK_TIME)); > writel(wdd->timeout * wdt->rate, wdt_addr(wdt, WDT_BITE_TIME)); > - writel(qcom_get_enable(wdd), wdt_addr(wdt, WDT_EN)); > + writel(QCOM_WDT_ENABLE, wdt_addr(wdt, WDT_EN)); > return 0; > } > >
On 2021-01-26 20:53, Guenter Roeck wrote: > On 1/26/21 7:02 AM, Sai Prakash Ranjan wrote: >> As per register documentation, QCOM_WDT_ENABLE_IRQ which is BIT(1) >> of watchdog control register is wakeup interrupt enable bit and >> not related to bark interrupt at all, BIT(0) is used for that. >> So remove incorrect usage of this bit when supporting bark irq for >> pre-timeout notification. Currently with this bit set and bark >> interrupt specified, pre-timeout notification and/or watchdog >> reset/bite does not occur. >> >> Fixes: 36375491a439 ("watchdog: qcom: support pre-timeout when the >> bark irq is available") >> Cc: stable@vger.kernel.org >> Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> > > Assuming that pretimeout _does_ work with this patch applied, > > Reviewed-by: Guenter Roeck <linux@roeck-us.net> > Thanks Guenter. Yes I have patchset ready and tested [1] on 4 different SoCs on which pretimeout works with this patch and without this, watchdog functionality would be broken on all those platforms and possibly more(the ones I couldn't get access to) if we add bark irq to the watchdog DT node. [1] https://lore.kernel.org/patchwork/cover/1371270/ Thanks, Sai
Quoting Sai Prakash Ranjan (2021-01-26 07:02:41) > As per register documentation, QCOM_WDT_ENABLE_IRQ which is BIT(1) > of watchdog control register is wakeup interrupt enable bit and > not related to bark interrupt at all, BIT(0) is used for that. > So remove incorrect usage of this bit when supporting bark irq for > pre-timeout notification. Currently with this bit set and bark > interrupt specified, pre-timeout notification and/or watchdog > reset/bite does not occur. It looks like the QCOM_WDT_ENABLE_IRQ bit is to catch a problem where a pending irq is unmasked but the watchdog irq isn't handled in time? So some sort of irq storm? > > Fixes: 36375491a439 ("watchdog: qcom: support pre-timeout when the bark irq is available") > Cc: stable@vger.kernel.org > Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> > --- Reviewed-by: Stephen Boyd <swboyd@chromium.org>
On 26/01/21, Sai Prakash Ranjan wrote: > As per register documentation, QCOM_WDT_ENABLE_IRQ which is BIT(1) > of watchdog control register is wakeup interrupt enable bit and > not related to bark interrupt at all, BIT(0) is used for that. > So remove incorrect usage of this bit when supporting bark irq for > pre-timeout notification. Currently with this bit set and bark > interrupt specified, pre-timeout notification and/or watchdog > reset/bite does not occur. > > Fixes: 36375491a439 ("watchdog: qcom: support pre-timeout when the bark irq is available") > Cc: stable@vger.kernel.org > Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> > --- > > Reading the conversations from when qcom pre-timeout support was > added [1], Bjorn already had mentioned it was not right to touch this > bit, not sure which SoC the pre-timeout was tested on at that time, > but I have tested this on SDM845, SM8150, SC7180 and watchdog bark > and bite does not occur with enabling this bit with the bark irq > specified in DT. this was tested on QCS404. have you validated there? unfortunately I no longer have access to that hardware or the documentation > > [1] https://lore.kernel.org/linux-watchdog/20190906174009.GC11938@tuxbook-pro/ > > --- > drivers/watchdog/qcom-wdt.c | 13 +------------ > 1 file changed, 1 insertion(+), 12 deletions(-) > > diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c > index 7cf0f2ec649b..e38a87ffe5f5 100644 > --- a/drivers/watchdog/qcom-wdt.c > +++ b/drivers/watchdog/qcom-wdt.c > @@ -22,7 +22,6 @@ enum wdt_reg { > }; > > #define QCOM_WDT_ENABLE BIT(0) > -#define QCOM_WDT_ENABLE_IRQ BIT(1) > > static const u32 reg_offset_data_apcs_tmr[] = { > [WDT_RST] = 0x38, > @@ -63,16 +62,6 @@ struct qcom_wdt *to_qcom_wdt(struct watchdog_device *wdd) > return container_of(wdd, struct qcom_wdt, wdd); > } > > -static inline int qcom_get_enable(struct watchdog_device *wdd) > -{ > - int enable = QCOM_WDT_ENABLE; > - > - if (wdd->pretimeout) > - enable |= QCOM_WDT_ENABLE_IRQ; > - > - return enable; > -} > - > static irqreturn_t qcom_wdt_isr(int irq, void *arg) > { > struct watchdog_device *wdd = arg; > @@ -91,7 +80,7 @@ static int qcom_wdt_start(struct watchdog_device *wdd) > writel(1, wdt_addr(wdt, WDT_RST)); > writel(bark * wdt->rate, wdt_addr(wdt, WDT_BARK_TIME)); > writel(wdd->timeout * wdt->rate, wdt_addr(wdt, WDT_BITE_TIME)); > - writel(qcom_get_enable(wdd), wdt_addr(wdt, WDT_EN)); > + writel(QCOM_WDT_ENABLE, wdt_addr(wdt, WDT_EN)); > return 0; > } > > -- > QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member > of Code Aurora Forum, hosted by The Linux Foundation >
On 2021-01-28 07:03, Stephen Boyd wrote: > Quoting Sai Prakash Ranjan (2021-01-26 07:02:41) >> As per register documentation, QCOM_WDT_ENABLE_IRQ which is BIT(1) >> of watchdog control register is wakeup interrupt enable bit and >> not related to bark interrupt at all, BIT(0) is used for that. >> So remove incorrect usage of this bit when supporting bark irq for >> pre-timeout notification. Currently with this bit set and bark >> interrupt specified, pre-timeout notification and/or watchdog >> reset/bite does not occur. > > It looks like the QCOM_WDT_ENABLE_IRQ bit is to catch a problem where a > pending irq is unmasked but the watchdog irq isn't handled in time? So > some sort of irq storm? > In sleep mode, this bit is used to enable unmasked irq to wakeup watchdog timer. The watchdog counter can be brought out of reset either by writing 1 to WDOG_RESET or setting this BIT(1) to 1. >> >> Fixes: 36375491a439 ("watchdog: qcom: support pre-timeout when the >> bark irq is available") >> Cc: stable@vger.kernel.org >> Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> >> --- > > Reviewed-by: Stephen Boyd <swboyd@chromium.org> > Thanks, Sai
On 2021-01-28 13:49, Jorge Ramirez-Ortiz, Foundries wrote: > On 26/01/21, Sai Prakash Ranjan wrote: >> As per register documentation, QCOM_WDT_ENABLE_IRQ which is BIT(1) >> of watchdog control register is wakeup interrupt enable bit and >> not related to bark interrupt at all, BIT(0) is used for that. >> So remove incorrect usage of this bit when supporting bark irq for >> pre-timeout notification. Currently with this bit set and bark >> interrupt specified, pre-timeout notification and/or watchdog >> reset/bite does not occur. >> >> Fixes: 36375491a439 ("watchdog: qcom: support pre-timeout when the >> bark irq is available") >> Cc: stable@vger.kernel.org >> Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> >> --- >> >> Reading the conversations from when qcom pre-timeout support was >> added [1], Bjorn already had mentioned it was not right to touch this >> bit, not sure which SoC the pre-timeout was tested on at that time, >> but I have tested this on SDM845, SM8150, SC7180 and watchdog bark >> and bite does not occur with enabling this bit with the bark irq >> specified in DT. > > this was tested on QCS404. have you validated there? unfortunately I > no longer have access to that hardware or the documentation > I didn't validate on qcs404 yet since I didn't have access to it. But now that you mention it, let me arrange for a setup and test it there as well. Note: I did not see bark irq entry in upstream qcs404 dtsi, so you must have had some local change when you tested? Thanks, Sai
diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c index 7cf0f2ec649b..e38a87ffe5f5 100644 --- a/drivers/watchdog/qcom-wdt.c +++ b/drivers/watchdog/qcom-wdt.c @@ -22,7 +22,6 @@ enum wdt_reg { }; #define QCOM_WDT_ENABLE BIT(0) -#define QCOM_WDT_ENABLE_IRQ BIT(1) static const u32 reg_offset_data_apcs_tmr[] = { [WDT_RST] = 0x38, @@ -63,16 +62,6 @@ struct qcom_wdt *to_qcom_wdt(struct watchdog_device *wdd) return container_of(wdd, struct qcom_wdt, wdd); } -static inline int qcom_get_enable(struct watchdog_device *wdd) -{ - int enable = QCOM_WDT_ENABLE; - - if (wdd->pretimeout) - enable |= QCOM_WDT_ENABLE_IRQ; - - return enable; -} - static irqreturn_t qcom_wdt_isr(int irq, void *arg) { struct watchdog_device *wdd = arg; @@ -91,7 +80,7 @@ static int qcom_wdt_start(struct watchdog_device *wdd) writel(1, wdt_addr(wdt, WDT_RST)); writel(bark * wdt->rate, wdt_addr(wdt, WDT_BARK_TIME)); writel(wdd->timeout * wdt->rate, wdt_addr(wdt, WDT_BITE_TIME)); - writel(qcom_get_enable(wdd), wdt_addr(wdt, WDT_EN)); + writel(QCOM_WDT_ENABLE, wdt_addr(wdt, WDT_EN)); return 0; }
As per register documentation, QCOM_WDT_ENABLE_IRQ which is BIT(1) of watchdog control register is wakeup interrupt enable bit and not related to bark interrupt at all, BIT(0) is used for that. So remove incorrect usage of this bit when supporting bark irq for pre-timeout notification. Currently with this bit set and bark interrupt specified, pre-timeout notification and/or watchdog reset/bite does not occur. Fixes: 36375491a439 ("watchdog: qcom: support pre-timeout when the bark irq is available") Cc: stable@vger.kernel.org Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> --- Reading the conversations from when qcom pre-timeout support was added [1], Bjorn already had mentioned it was not right to touch this bit, not sure which SoC the pre-timeout was tested on at that time, but I have tested this on SDM845, SM8150, SC7180 and watchdog bark and bite does not occur with enabling this bit with the bark irq specified in DT. [1] https://lore.kernel.org/linux-watchdog/20190906174009.GC11938@tuxbook-pro/ --- drivers/watchdog/qcom-wdt.c | 13 +------------ 1 file changed, 1 insertion(+), 12 deletions(-)