| Message ID | 1586946198-13912-5-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| State | Superseded |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 Wed, Apr 15, 2020 at 03:53:13PM +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 in 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. > > Change in V4: > - As per Matthias comment make 'earlycon_wrapper' as static structure. > > drivers/soc/qcom/qcom-geni-se.c | 50 +++++++++++++++++++++++++++++++++++ > drivers/tty/serial/qcom_geni_serial.c | 7 +++++ > include/linux/qcom-geni-se.h | 2 ++ > 3 files changed, 59 insertions(+) > > diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c > index 1527bc4..727ad2e 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; > }; > > +static struct geni_wrapper *earlycon_wrapper; > + > #define QUP_HW_VER_REG 0x4 > > /* Common SE registers */ > @@ -781,6 +784,26 @@ 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; > @@ -808,6 +831,33 @@ 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, 0); > + 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; The idea of using the exit handler of the early console to remove the votes seemed appealing at first, however it has a drawback: the bandwidth requests in geni_se_probe() are always made when CONFIG_SERIAL_EARLYCON=y, also when the system doesn't actually use an early console. On such a system the votes would never be removed. A possible alternative could seem to remove the vote at the end of qcom_geni_serial_probe() of the 'normal' console, but it has a similar problem: the system could not even have a normal console. One could possibly argue that CONFIG_SERIAL_QCOM_GENI_CONSOLE shouldn't be set on such a system, however it could be enabled to have a console for development, and in production the same kernel config is used, but with the console disabled through the device tree. I don't really have a good idea at this point, maybe we just need something as ugly as a delayed work to remove the votes. Other suggestions are welcome :)
Hi Matthias, On 4/16/2020 6:01 AM, Matthias Kaehlcke wrote: > Hi Akash, > > On Wed, Apr 15, 2020 at 03:53:13PM +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 in 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. >> >> Change in V4: >> - As per Matthias comment make 'earlycon_wrapper' as static structure. >> >> drivers/soc/qcom/qcom-geni-se.c | 50 +++++++++++++++++++++++++++++++++++ >> drivers/tty/serial/qcom_geni_serial.c | 7 +++++ >> include/linux/qcom-geni-se.h | 2 ++ >> 3 files changed, 59 insertions(+) >> >> diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c >> index 1527bc4..727ad2e 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; >> }; >> >> +static struct geni_wrapper *earlycon_wrapper; >> + >> #define QUP_HW_VER_REG 0x4 >> >> /* Common SE registers */ >> @@ -781,6 +784,26 @@ 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; >> @@ -808,6 +831,33 @@ 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, 0); >> + 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; > The idea of using the exit handler of the early console to remove the > votes seemed appealing at first, however it has a drawback: the bandwidth > requests in geni_se_probe() are always made when CONFIG_SERIAL_EARLYCON=y, > also when the system doesn't actually use an early console. On such a > system the votes would never be removed. > > A possible alternative could seem to remove the vote at the end of > qcom_geni_serial_probe() of the 'normal' console, but it has a similar > problem: the system could not even have a normal console. One could > possibly argue that CONFIG_SERIAL_QCOM_GENI_CONSOLE shouldn't be set > on such a system, however it could be enabled to have a console for > development, and in production the same kernel config is used, but > with the console disabled through the device tree. > > I don't really have a good idea at this point, maybe we just need > something as ugly as a delayed work to remove the votes. Other > suggestions are welcome :) I think we can do something like below. Before voting we are checking whether earlyconsole ("qcom_geni") exits or not. The name is fixed from earlycon declaration file@drivers/tty/serial/qcom_geni_serial.c OF_EARLYCON_DECLARE(qcom_geni, "qcom,geni-debug-uart", qcom_geni_serial_earlycon_setup); ==================================================================================== @@ -809,6 +809,8 @@ static int geni_se_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct resource *res; struct geni_wrapper *wrapper; + struct console *bcon = NULL; + int earlycon_present = 0; int ret; wrapper = devm_kzalloc(dev, sizeof(*wrapper), GFP_KERNEL); @@ -832,6 +834,15 @@ static int geni_se_probe(struct platform_device *pdev) } #ifdef CONFIG_SERIAL_EARLYCON + if (console_drivers) + for_each_console(bcon) + if (!strcmp(bcon->name, "qcom_geni")) { + earlycon_present = 1; + break; + } + if(!earlycon_present) + goto exit; + 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); @@ -858,6 +869,7 @@ static int geni_se_probe(struct platform_device *pdev) of_node_put(pdev->dev.of_node); #endif +exit: dev_set_drvdata(dev, wrapper); dev_dbg(dev, "GENI SE Driver probed\n"); return devm_of_platform_populate(dev); ====================================================================================== Regards, Akash
Hi Akash, On Tue, Apr 28, 2020 at 03:51:44PM +0530, Akash Asthana wrote: > Hi Matthias, > > On 4/16/2020 6:01 AM, Matthias Kaehlcke wrote: > > Hi Akash, > > > > On Wed, Apr 15, 2020 at 03:53:13PM +0530, Akash Asthana wrote: ... > > > 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; > > The idea of using the exit handler of the early console to remove the > > votes seemed appealing at first, however it has a drawback: the bandwidth > > requests in geni_se_probe() are always made when CONFIG_SERIAL_EARLYCON=y, > > also when the system doesn't actually use an early console. On such a > > system the votes would never be removed. > > > > A possible alternative could seem to remove the vote at the end of > > qcom_geni_serial_probe() of the 'normal' console, but it has a similar > > problem: the system could not even have a normal console. One could > > possibly argue that CONFIG_SERIAL_QCOM_GENI_CONSOLE shouldn't be set > > on such a system, however it could be enabled to have a console for > > development, and in production the same kernel config is used, but > > with the console disabled through the device tree. > > > > I don't really have a good idea at this point, maybe we just need > > something as ugly as a delayed work to remove the votes. Other > > suggestions are welcome :) > > I think we can do something like below. Before voting we are checking > whether earlyconsole ("qcom_geni") exits or not. The name is fixed from > earlycon declaration file@drivers/tty/serial/qcom_geni_serial.c > > OF_EARLYCON_DECLARE(qcom_geni, "qcom,geni-debug-uart", > qcom_geni_serial_earlycon_setup); > > ==================================================================================== > > @@ -809,6 +809,8 @@ static int geni_se_probe(struct platform_device *pdev) > struct device *dev = &pdev->dev; > struct resource *res; > struct geni_wrapper *wrapper; > + struct console *bcon = NULL; nit: initialization is not needed > + int earlycon_present = 0; > int ret; > > wrapper = devm_kzalloc(dev, sizeof(*wrapper), GFP_KERNEL); > @@ -832,6 +834,15 @@ static int geni_se_probe(struct platform_device *pdev) > } > > #ifdef CONFIG_SERIAL_EARLYCON > + if (console_drivers) > + for_each_console(bcon) > + if (!strcmp(bcon->name, "qcom_geni")) { > + earlycon_present = 1; > + break; > + } > + if(!earlycon_present) > + goto exit; > + > 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); > @@ -858,6 +869,7 @@ static int geni_se_probe(struct platform_device *pdev) > of_node_put(pdev->dev.of_node); > #endif > > +exit: > dev_set_drvdata(dev, wrapper); > dev_dbg(dev, "GENI SE Driver probed\n"); > return devm_of_platform_populate(dev); > This should work as long as the early console is always set up before geni_se is probed, which seems a safe assumption.
diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c index 1527bc4..727ad2e 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; }; +static struct geni_wrapper *earlycon_wrapper; + #define QUP_HW_VER_REG 0x4 /* Common SE registers */ @@ -781,6 +784,26 @@ 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; @@ -808,6 +831,33 @@ 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, 0); + 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 b5b9316..cf2b8d4 100644 --- a/include/linux/qcom-geni-se.h +++ b/include/linux/qcom-geni-se.h @@ -447,5 +447,7 @@ int geni_icc_get(struct geni_se *se, const char *icc_ddr); 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 in 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. Change in V4: - As per Matthias comment make 'earlycon_wrapper' as static structure. drivers/soc/qcom/qcom-geni-se.c | 50 +++++++++++++++++++++++++++++++++++ drivers/tty/serial/qcom_geni_serial.c | 7 +++++ include/linux/qcom-geni-se.h | 2 ++ 3 files changed, 59 insertions(+)