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charset=utf-8 Content-Disposition: inline In-Reply-To: <1585652976-17481-4-git-send-email-akashast@codeaurora.org> User-Agent: Mutt/1.12.2 (2019-09-21) Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org 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 > Reported-by: Matthias Kaehlcke > --- > 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? From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthias Kaehlcke Subject: Re: [PATCH V3 3/8] soc: qcom-geni-se: Add interconnect support to fix earlycon crash Date: Tue, 31 Mar 2020 11:24:57 -0700 Message-ID: <20200331182457.GH199755@google.com> References: <1585652976-17481-1-git-send-email-akashast@codeaurora.org> <1585652976-17481-4-git-send-email-akashast@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <1585652976-17481-4-git-send-email-akashast-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Akash Asthana Cc: gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, agross-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, bjorn.andersson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org, broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, georgi.djakov-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, swboyd-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org, mgautam-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, linux-arm-msm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-serial-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org, evgreen-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org List-Id: linux-i2c@vger.kernel.org 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 > Reported-by: Matthias Kaehlcke > --- > 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?