| Message ID | 1585652976-17481-4-git-send-email-akashast@codeaurora.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add interconnect support to QSPI and QUP drivers | expand |
Hi Akash, On Tue, Mar 31, 2020 at 04:39:31PM +0530, Akash Asthana wrote: > QUP core clock is shared among all the SE drivers present on particular > QUP wrapper, the system will reset(unclocked access) if earlycon used after > QUP core clock is put to 0 from other SE drivers before real console comes > up. > > As earlycon can't vote for it's QUP core need, to fix this add ICC > support to common/QUP wrapper driver and put vote for QUP core from > probe on behalf of earlycon and remove vote during earlycon exit call. > > Signed-off-by: Akash Asthana <akashast@codeaurora.org> > Reported-by: Matthias Kaehlcke <mka@chromium.org> > --- > Change is V3: > - Add geni_remove_earlycon_icc_vote API that will be used by earlycon > exit function to remove ICC vote for earlyconsole. > - Remove suspend/resume hook for geni-se driver as we are no longer > removing earlyconsole ICC vote from system suspend, we are removing > from earlycon exit. > > drivers/soc/qcom/qcom-geni-se.c | 51 +++++++++++++++++++++++++++++++++++ > drivers/tty/serial/qcom_geni_serial.c | 7 +++++ > include/linux/qcom-geni-se.h | 2 ++ > 3 files changed, 60 insertions(+) > > diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c > index 9344c14..d30c282 100644 > --- a/drivers/soc/qcom/qcom-geni-se.c > +++ b/drivers/soc/qcom/qcom-geni-se.c > @@ -90,8 +90,11 @@ struct geni_wrapper { > struct device *dev; > void __iomem *base; > struct clk_bulk_data ahb_clks[NUM_AHB_CLKS]; > + struct geni_icc_path to_core; > }; > > +struct geni_wrapper *earlycon_wrapper; should be static > + > #define QUP_HW_VER_REG 0x4 > > /* Common SE registers */ > @@ -818,6 +821,26 @@ int geni_icc_vote_off(struct geni_se *se) > } > EXPORT_SYMBOL(geni_icc_vote_off); > > +void geni_remove_earlycon_icc_vote(void) > +{ > + struct geni_wrapper *wrapper = earlycon_wrapper; > + struct device_node *parent = of_get_next_parent(wrapper->dev->of_node); > + struct device_node *child; > + > + for_each_child_of_node(parent, child) { > + if (of_device_is_compatible(child, "qcom,geni-se-qup")) { > + wrapper = platform_get_drvdata(of_find_device_by_node( > + child)); > + icc_put(wrapper->to_core.path); > + wrapper->to_core.path = NULL; > + } > + } > + of_node_put(parent); > + > + earlycon_wrapper = NULL; > +} > +EXPORT_SYMBOL(geni_remove_earlycon_icc_vote); I didn't know that consoles have an exit handler, this is way nicer than the miscellaneous triggers we discussed earlier :) > + > static int geni_se_probe(struct platform_device *pdev) > { > struct device *dev = &pdev->dev; > @@ -845,6 +868,34 @@ static int geni_se_probe(struct platform_device *pdev) > } > } > > +#ifdef CONFIG_SERIAL_EARLYCON > + wrapper->to_core.path = devm_of_icc_get(dev, "qup-core"); > + if (IS_ERR(wrapper->to_core.path)) > + return PTR_ERR(wrapper->to_core.path); > + /* > + * Put minmal BW request on core clocks on behalf of early console. > + * The vote will be removed earlycon exit function. > + * > + * Note: We are putting vote on each QUP wrapper instead only to which > + * earlycon is connected because QUP core clock of different wrapper > + * share same voltage domain. If core1 is put to 0, then core2 will > + * also run at 0, if not voted. Default ICC vote will be removed ASA > + * we touch any of the core clock. > + * core1 = core2 = max(core1, core2) > + */ I don't really understand this part. According to the comment if we vote (let's say) for core2 but not for core1 then: core1: 0 core2: GENI_DEFAULT_BW core1 = core2 = max(core1, core2) or core1 = core2 = max(0, GENI_DEFAULT_BW) hence core1 = core2 = GENI_DEFAULT_BW What am I missing, why is it necessary to vote for both/all?
On Tue, Mar 31, 2020 at 11:24:57AM -0700, Matthias Kaehlcke wrote: > Hi Akash, > > On Tue, Mar 31, 2020 at 04:39:31PM +0530, Akash Asthana wrote: > > QUP core clock is shared among all the SE drivers present on particular > > QUP wrapper, the system will reset(unclocked access) if earlycon used after > > QUP core clock is put to 0 from other SE drivers before real console comes > > up. > > > > As earlycon can't vote for it's QUP core need, to fix this add ICC > > support to common/QUP wrapper driver and put vote for QUP core from > > probe on behalf of earlycon and remove vote during earlycon exit call. > > > > Signed-off-by: Akash Asthana <akashast@codeaurora.org> > > Reported-by: Matthias Kaehlcke <mka@chromium.org> > > --- > > Change is V3: > > - Add geni_remove_earlycon_icc_vote API that will be used by earlycon > > exit function to remove ICC vote for earlyconsole. > > - Remove suspend/resume hook for geni-se driver as we are no longer > > removing earlyconsole ICC vote from system suspend, we are removing > > from earlycon exit. > > > > drivers/soc/qcom/qcom-geni-se.c | 51 +++++++++++++++++++++++++++++++++++ > > drivers/tty/serial/qcom_geni_serial.c | 7 +++++ > > include/linux/qcom-geni-se.h | 2 ++ > > 3 files changed, 60 insertions(+) > > > > diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c > > index 9344c14..d30c282 100644 > > --- a/drivers/soc/qcom/qcom-geni-se.c > > +++ b/drivers/soc/qcom/qcom-geni-se.c > > @@ -90,8 +90,11 @@ struct geni_wrapper { > > struct device *dev; > > void __iomem *base; > > struct clk_bulk_data ahb_clks[NUM_AHB_CLKS]; > > + struct geni_icc_path to_core; > > }; > > > > +struct geni_wrapper *earlycon_wrapper; > > should be static > > > + > > #define QUP_HW_VER_REG 0x4 > > > > /* Common SE registers */ > > @@ -818,6 +821,26 @@ int geni_icc_vote_off(struct geni_se *se) > > } > > EXPORT_SYMBOL(geni_icc_vote_off); > > > > +void geni_remove_earlycon_icc_vote(void) > > +{ > > + struct geni_wrapper *wrapper = earlycon_wrapper; > > + struct device_node *parent = of_get_next_parent(wrapper->dev->of_node); > > + struct device_node *child; > > + > > + for_each_child_of_node(parent, child) { > > + if (of_device_is_compatible(child, "qcom,geni-se-qup")) { > > + wrapper = platform_get_drvdata(of_find_device_by_node( > > + child)); > > + icc_put(wrapper->to_core.path); > > + wrapper->to_core.path = NULL; > > + } > > + } > > + of_node_put(parent); > > + > > + earlycon_wrapper = NULL; > > +} > > +EXPORT_SYMBOL(geni_remove_earlycon_icc_vote); > > I didn't know that consoles have an exit handler, this is way nicer than > the miscellaneous triggers we discussed earlier :) No wonder I 'missed' this when looking at the console code for possible triggers, it is brand new and as of now only exists in -next: commit ed31685c96e18f773ca11dd1a637974d62130673 Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Date: Mon Feb 3 15:31:30 2020 +0200 console: Introduce ->exit() callback sharp timing!
Hi Matthias On 4/2/2020 1:16 AM, Matthias Kaehlcke wrote: > On Tue, Mar 31, 2020 at 11:24:57AM -0700, Matthias Kaehlcke wrote: >> Hi Akash, >> >> On Tue, Mar 31, 2020 at 04:39:31PM +0530, Akash Asthana wrote: >>> QUP core clock is shared among all the SE drivers present on particular >>> QUP wrapper, the system will reset(unclocked access) if earlycon used after >>> QUP core clock is put to 0 from other SE drivers before real console comes >>> up. >>> >>> As earlycon can't vote for it's QUP core need, to fix this add ICC >>> support to common/QUP wrapper driver and put vote for QUP core from >>> probe on behalf of earlycon and remove vote during earlycon exit call. >>> >>> Signed-off-by: Akash Asthana <akashast@codeaurora.org> >>> Reported-by: Matthias Kaehlcke <mka@chromium.org> >>> --- >>> Change is V3: >>> - Add geni_remove_earlycon_icc_vote API that will be used by earlycon >>> exit function to remove ICC vote for earlyconsole. >>> - Remove suspend/resume hook for geni-se driver as we are no longer >>> removing earlyconsole ICC vote from system suspend, we are removing >>> from earlycon exit. >>> >>> drivers/soc/qcom/qcom-geni-se.c | 51 +++++++++++++++++++++++++++++++++++ >>> drivers/tty/serial/qcom_geni_serial.c | 7 +++++ >>> include/linux/qcom-geni-se.h | 2 ++ >>> 3 files changed, 60 insertions(+) >>> >>> diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c >>> index 9344c14..d30c282 100644 >>> --- a/drivers/soc/qcom/qcom-geni-se.c >>> +++ b/drivers/soc/qcom/qcom-geni-se.c >>> @@ -90,8 +90,11 @@ struct geni_wrapper { >>> struct device *dev; >>> void __iomem *base; >>> struct clk_bulk_data ahb_clks[NUM_AHB_CLKS]; >>> + struct geni_icc_path to_core; >>> }; >>> >>> +struct geni_wrapper *earlycon_wrapper; >> should be static Yeah ok, I missed it. >> >>> + >>> #define QUP_HW_VER_REG 0x4 >>> >>> /* Common SE registers */ >>> @@ -818,6 +821,26 @@ int geni_icc_vote_off(struct geni_se *se) >>> } >>> EXPORT_SYMBOL(geni_icc_vote_off); >>> >>> +void geni_remove_earlycon_icc_vote(void) >>> +{ >>> + struct geni_wrapper *wrapper = earlycon_wrapper; >>> + struct device_node *parent = of_get_next_parent(wrapper->dev->of_node); >>> + struct device_node *child; >>> + >>> + for_each_child_of_node(parent, child) { >>> + if (of_device_is_compatible(child, "qcom,geni-se-qup")) { >>> + wrapper = platform_get_drvdata(of_find_device_by_node( >>> + child)); >>> + icc_put(wrapper->to_core.path); >>> + wrapper->to_core.path = NULL; >>> + } >>> + } >>> + of_node_put(parent); >>> + >>> + earlycon_wrapper = NULL; >>> +} >>> +EXPORT_SYMBOL(geni_remove_earlycon_icc_vote); >> I didn't know that consoles have an exit handler, this is way nicer than >> the miscellaneous triggers we discussed earlier :) > No wonder I 'missed' this when looking at the console code for possible > triggers, it is brand new and as of now only exists in -next: > > commit ed31685c96e18f773ca11dd1a637974d62130673 > Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Date: Mon Feb 3 15:31:30 2020 +0200 > > console: Introduce ->exit() callback > > > sharp timing! Yeah this is added recently, even I was not aware of it, Bjorn suggested me to use this. Indeed sharp timing! :) Regards, Akash
Hi Matthias, >> static int geni_se_probe(struct platform_device *pdev) >> { >> struct device *dev = &pdev->dev; >> @@ -845,6 +868,34 @@ static int geni_se_probe(struct platform_device *pdev) >> } >> } >> >> +#ifdef CONFIG_SERIAL_EARLYCON >> + wrapper->to_core.path = devm_of_icc_get(dev, "qup-core"); >> + if (IS_ERR(wrapper->to_core.path)) >> + return PTR_ERR(wrapper->to_core.path); >> + /* >> + * Put minmal BW request on core clocks on behalf of early console. >> + * The vote will be removed earlycon exit function. >> + * >> + * Note: We are putting vote on each QUP wrapper instead only to which >> + * earlycon is connected because QUP core clock of different wrapper >> + * share same voltage domain. If core1 is put to 0, then core2 will >> + * also run at 0, if not voted. Default ICC vote will be removed ASA >> + * we touch any of the core clock. >> + * core1 = core2 = max(core1, core2) >> + */ > I don't really understand this part. According to the comment if we vote > (let's say) for core2 but not for core1 then: > > core1: 0 > core2: GENI_DEFAULT_BW > > core1 = core2 = max(core1, core2) > or > core1 = core2 = max(0, GENI_DEFAULT_BW) > > hence > > core1 = core2 = GENI_DEFAULT_BW > > What am I missing, why is it necessary to vote for both/all? say core1 is for earlycon usecase There is common switch to control both the QUP core clock. I guess most appropriate description would be switch = max(vote_on_core1, vote_on_core2) + default_vote. During early bootup, vote_on_core1 = 0, vote_on_core2 = 0; As earlycon was working even without voting it's core need because there was some default vote present on the core switch by ICC during bootup. So if any child(say SPI) of other QUP wrapper resumed and suspended before earlycon wrapper comes up. This will make core clock to run at zero and will cause NOC issue because vote_on_core1 = 0, vote_on_core2 = 0; and it seems default votes from core switch is removed ASA it's voted on any core. Regards, Akash
Hi Akash, On Tue, Apr 07, 2020 at 05:04:17PM +0530, Akash Asthana wrote: > Hi Matthias, > > > > > static int geni_se_probe(struct platform_device *pdev) > > > { > > > struct device *dev = &pdev->dev; > > > @@ -845,6 +868,34 @@ static int geni_se_probe(struct platform_device *pdev) > > > } > > > } > > > +#ifdef CONFIG_SERIAL_EARLYCON > > > + wrapper->to_core.path = devm_of_icc_get(dev, "qup-core"); > > > + if (IS_ERR(wrapper->to_core.path)) > > > + return PTR_ERR(wrapper->to_core.path); > > > + /* > > > + * Put minmal BW request on core clocks on behalf of early console. > > > + * The vote will be removed earlycon exit function. > > > + * > > > + * Note: We are putting vote on each QUP wrapper instead only to which > > > + * earlycon is connected because QUP core clock of different wrapper > > > + * share same voltage domain. If core1 is put to 0, then core2 will > > > + * also run at 0, if not voted. Default ICC vote will be removed ASA > > > + * we touch any of the core clock. > > > + * core1 = core2 = max(core1, core2) > > > + */ > > I don't really understand this part. According to the comment if we vote > > (let's say) for core2 but not for core1 then: > > > > core1: 0 > > core2: GENI_DEFAULT_BW > > > > core1 = core2 = max(core1, core2) > > or > > core1 = core2 = max(0, GENI_DEFAULT_BW) > > > > hence > > > > core1 = core2 = GENI_DEFAULT_BW > > > > What am I missing, why is it necessary to vote for both/all? > say core1 is for earlycon usecase > > There is common switch to control both the QUP core clock. I guess most > appropriate description would be switch = max(vote_on_core1, > vote_on_core2) + default_vote. > > During early bootup, vote_on_core1 = 0, vote_on_core2 = 0; > > As earlycon was working even without voting it's core need because there was > some default vote present on the core switch by ICC during bootup. > > So if any child(say SPI) of other QUP wrapper resumed and suspended before > earlycon wrapper comes up. This will make core clock to run at zero and will > cause NOC issue because vote_on_core1 = 0, vote_on_core2 = 0; and it seems > default votes from core switch is removed ASA it's voted on any core. Thanks for the explication! You are probably totally right, but for some reason my brain still resists to get it ... With the above my current interpretation is (assuming earlycon only votes on core1): core1 core2 default switch early boot 0 0 1 1 SPI resume (core2) 0 1 0 1 SPI suspend (core2) 0 0 0 0 earlycon init 1 0 0 1 What is wrong in the above table? Thanks for bearing with me :) Matthias
Hi Matthias, On 4/7/2020 10:56 PM, Matthias Kaehlcke wrote: > Hi Akash, > > On Tue, Apr 07, 2020 at 05:04:17PM +0530, Akash Asthana wrote: >> Hi Matthias, >> >> >>>> static int geni_se_probe(struct platform_device *pdev) >>>> { >>>> struct device *dev = &pdev->dev; >>>> @@ -845,6 +868,34 @@ static int geni_se_probe(struct platform_device *pdev) >>>> } >>>> } >>>> +#ifdef CONFIG_SERIAL_EARLYCON >>>> + wrapper->to_core.path = devm_of_icc_get(dev, "qup-core"); >>>> + if (IS_ERR(wrapper->to_core.path)) >>>> + return PTR_ERR(wrapper->to_core.path); >>>> + /* >>>> + * Put minmal BW request on core clocks on behalf of early console. >>>> + * The vote will be removed earlycon exit function. >>>> + * >>>> + * Note: We are putting vote on each QUP wrapper instead only to which >>>> + * earlycon is connected because QUP core clock of different wrapper >>>> + * share same voltage domain. If core1 is put to 0, then core2 will >>>> + * also run at 0, if not voted. Default ICC vote will be removed ASA >>>> + * we touch any of the core clock. >>>> + * core1 = core2 = max(core1, core2) >>>> + */ >>> I don't really understand this part. According to the comment if we vote >>> (let's say) for core2 but not for core1 then: >>> >>> core1: 0 >>> core2: GENI_DEFAULT_BW >>> >>> core1 = core2 = max(core1, core2) >>> or >>> core1 = core2 = max(0, GENI_DEFAULT_BW) >>> >>> hence >>> >>> core1 = core2 = GENI_DEFAULT_BW >>> >>> What am I missing, why is it necessary to vote for both/all? >> say core1 is for earlycon usecase >> >> There is common switch to control both the QUP core clock. I guess most >> appropriate description would be switch = max(vote_on_core1, >> vote_on_core2) + default_vote. >> >> During early bootup, vote_on_core1 = 0, vote_on_core2 = 0; >> >> As earlycon was working even without voting it's core need because there was >> some default vote present on the core switch by ICC during bootup. >> >> So if any child(say SPI) of other QUP wrapper resumed and suspended before >> earlycon wrapper comes up. This will make core clock to run at zero and will >> cause NOC issue because vote_on_core1 = 0, vote_on_core2 = 0; and it seems >> default votes from core switch is removed ASA it's voted on any core. > Thanks for the explication! > > You are probably totally right, but for some reason my brain still resists > to get it ... > > With the above my current interpretation is (assuming earlycon only votes on > core1): > > core1 core2 default switch > early boot 0 0 1 1 > SPI resume (core2) 0 1 0 1 > SPI suspend (core2) 0 0 0 0 > earlycon init 1 0 0 1 > > > What is wrong in the above table? > > Thanks for bearing with me :) NP :) I guess you meant QUP WRAPPER 1 probe by "earlycon init". core1 core2 default switch Time early boot 0 0 1 1 0s SPI resume (core2) 0 1 0 1 3.2s SPI suspend (core2) 0 0 0 0 3.3s QUP WRAPPER 1(probe) 1 0 0 1 5s (say) So switch is at 0 in time interval [3.3, 5] that will make core clock to run at 0. If we use earlycon during this time interval it will reset the board. Did above answered the query? Regards, Akash > > Matthias
On Wed, Apr 08, 2020 at 05:08:01PM +0530, Akash Asthana wrote: > Hi Matthias, > > On 4/7/2020 10:56 PM, Matthias Kaehlcke wrote: > > Hi Akash, > > > > On Tue, Apr 07, 2020 at 05:04:17PM +0530, Akash Asthana wrote: > > > Hi Matthias, > > > > > > > > > > > static int geni_se_probe(struct platform_device *pdev) > > > > > { > > > > > struct device *dev = &pdev->dev; > > > > > @@ -845,6 +868,34 @@ static int geni_se_probe(struct platform_device *pdev) > > > > > } > > > > > } > > > > > +#ifdef CONFIG_SERIAL_EARLYCON > > > > > + wrapper->to_core.path = devm_of_icc_get(dev, "qup-core"); > > > > > + if (IS_ERR(wrapper->to_core.path)) > > > > > + return PTR_ERR(wrapper->to_core.path); > > > > > + /* > > > > > + * Put minmal BW request on core clocks on behalf of early console. > > > > > + * The vote will be removed earlycon exit function. > > > > > + * > > > > > + * Note: We are putting vote on each QUP wrapper instead only to which > > > > > + * earlycon is connected because QUP core clock of different wrapper > > > > > + * share same voltage domain. If core1 is put to 0, then core2 will > > > > > + * also run at 0, if not voted. Default ICC vote will be removed ASA > > > > > + * we touch any of the core clock. > > > > > + * core1 = core2 = max(core1, core2) > > > > > + */ > > > > I don't really understand this part. According to the comment if we vote > > > > (let's say) for core2 but not for core1 then: > > > > > > > > core1: 0 > > > > core2: GENI_DEFAULT_BW > > > > > > > > core1 = core2 = max(core1, core2) > > > > or > > > > core1 = core2 = max(0, GENI_DEFAULT_BW) > > > > > > > > hence > > > > > > > > core1 = core2 = GENI_DEFAULT_BW > > > > > > > > What am I missing, why is it necessary to vote for both/all? > > > say core1 is for earlycon usecase > > > > > > There is common switch to control both the QUP core clock. I guess most > > > appropriate description would be switch = max(vote_on_core1, > > > vote_on_core2) + default_vote. > > > > > > During early bootup, vote_on_core1 = 0, vote_on_core2 = 0; > > > > > > As earlycon was working even without voting it's core need because there was > > > some default vote present on the core switch by ICC during bootup. > > > > > > So if any child(say SPI) of other QUP wrapper resumed and suspended before > > > earlycon wrapper comes up. This will make core clock to run at zero and will > > > cause NOC issue because vote_on_core1 = 0, vote_on_core2 = 0; and it seems > > > default votes from core switch is removed ASA it's voted on any core. > > Thanks for the explication! > > > > You are probably totally right, but for some reason my brain still resists > > to get it ... > > > > With the above my current interpretation is (assuming earlycon only votes on > > core1): > > > > core1 core2 default switch > > early boot 0 0 1 1 > > SPI resume (core2) 0 1 0 1 > > SPI suspend (core2) 0 0 0 0 > > earlycon init 1 0 0 1 > > > > > > What is wrong in the above table? > > > > Thanks for bearing with me :) > NP :) > > I guess you meant QUP WRAPPER 1 probe by "earlycon init". > > core1 core2 default switch Time > early boot 0 0 1 1 0s > SPI resume (core2) 0 1 0 1 3.2s > SPI suspend (core2) 0 0 0 0 3.3s > QUP WRAPPER 1(probe) 1 0 0 1 5s (say) > > So switch is at 0 in time interval [3.3, 5] that will make core clock to run at 0. > If we use earlycon during this time interval it will reset the board. > > Did above answered the query? now it finally made 'click', thanks :)
diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c index 9344c14..d30c282 100644 --- a/drivers/soc/qcom/qcom-geni-se.c +++ b/drivers/soc/qcom/qcom-geni-se.c @@ -90,8 +90,11 @@ struct geni_wrapper { struct device *dev; void __iomem *base; struct clk_bulk_data ahb_clks[NUM_AHB_CLKS]; + struct geni_icc_path to_core; }; +struct geni_wrapper *earlycon_wrapper; + #define QUP_HW_VER_REG 0x4 /* Common SE registers */ @@ -818,6 +821,26 @@ int geni_icc_vote_off(struct geni_se *se) } EXPORT_SYMBOL(geni_icc_vote_off); +void geni_remove_earlycon_icc_vote(void) +{ + struct geni_wrapper *wrapper = earlycon_wrapper; + struct device_node *parent = of_get_next_parent(wrapper->dev->of_node); + struct device_node *child; + + for_each_child_of_node(parent, child) { + if (of_device_is_compatible(child, "qcom,geni-se-qup")) { + wrapper = platform_get_drvdata(of_find_device_by_node( + child)); + icc_put(wrapper->to_core.path); + wrapper->to_core.path = NULL; + } + } + of_node_put(parent); + + earlycon_wrapper = NULL; +} +EXPORT_SYMBOL(geni_remove_earlycon_icc_vote); + static int geni_se_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -845,6 +868,34 @@ static int geni_se_probe(struct platform_device *pdev) } } +#ifdef CONFIG_SERIAL_EARLYCON + wrapper->to_core.path = devm_of_icc_get(dev, "qup-core"); + if (IS_ERR(wrapper->to_core.path)) + return PTR_ERR(wrapper->to_core.path); + /* + * Put minmal BW request on core clocks on behalf of early console. + * The vote will be removed earlycon exit function. + * + * Note: We are putting vote on each QUP wrapper instead only to which + * earlycon is connected because QUP core clock of different wrapper + * share same voltage domain. If core1 is put to 0, then core2 will + * also run at 0, if not voted. Default ICC vote will be removed ASA + * we touch any of the core clock. + * core1 = core2 = max(core1, core2) + */ + ret = icc_set_bw(wrapper->to_core.path, GENI_DEFAULT_BW, + GENI_DEFAULT_BW); + if (ret) { + dev_err(&pdev->dev, "%s: ICC BW voting failed for core\n", + __func__); + return ret; + } + + if (of_get_compatible_child(pdev->dev.of_node, "qcom,geni-debug-uart")) + earlycon_wrapper = wrapper; + of_node_put(pdev->dev.of_node); +#endif + dev_set_drvdata(dev, wrapper); dev_dbg(dev, "GENI SE Driver probed\n"); return devm_of_platform_populate(dev); diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 6119090..8c5d97c 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -1090,6 +1090,12 @@ static void qcom_geni_serial_earlycon_write(struct console *con, __qcom_geni_serial_console_write(&dev->port, s, n); } +static int qcom_geni_serial_earlycon_exit(struct console *con) +{ + geni_remove_earlycon_icc_vote(); + return 0; +} + static int __init qcom_geni_serial_earlycon_setup(struct earlycon_device *dev, const char *opt) { @@ -1135,6 +1141,7 @@ static int __init qcom_geni_serial_earlycon_setup(struct earlycon_device *dev, writel(stop_bit_len, uport->membase + SE_UART_TX_STOP_BIT_LEN); dev->con->write = qcom_geni_serial_earlycon_write; + dev->con->exit = qcom_geni_serial_earlycon_exit; dev->con->setup = NULL; return 0; } diff --git a/include/linux/qcom-geni-se.h b/include/linux/qcom-geni-se.h index a83c86b..c830b38 100644 --- a/include/linux/qcom-geni-se.h +++ b/include/linux/qcom-geni-se.h @@ -452,5 +452,7 @@ int geni_icc_get(struct geni_se *se, const char *icc_core, const char *icc_cpu, int geni_icc_vote_on(struct geni_se *se); int geni_icc_vote_off(struct geni_se *se); + +void geni_remove_earlycon_icc_vote(void); #endif #endif
QUP core clock is shared among all the SE drivers present on particular QUP wrapper, the system will reset(unclocked access) if earlycon used after QUP core clock is put to 0 from other SE drivers before real console comes up. As earlycon can't vote for it's QUP core need, to fix this add ICC support to common/QUP wrapper driver and put vote for QUP core from probe on behalf of earlycon and remove vote during earlycon exit call. Signed-off-by: Akash Asthana <akashast@codeaurora.org> Reported-by: Matthias Kaehlcke <mka@chromium.org> --- Change is V3: - Add geni_remove_earlycon_icc_vote API that will be used by earlycon exit function to remove ICC vote for earlyconsole. - Remove suspend/resume hook for geni-se driver as we are no longer removing earlyconsole ICC vote from system suspend, we are removing from earlycon exit. drivers/soc/qcom/qcom-geni-se.c | 51 +++++++++++++++++++++++++++++++++++ drivers/tty/serial/qcom_geni_serial.c | 7 +++++ include/linux/qcom-geni-se.h | 2 ++ 3 files changed, 60 insertions(+)