| Message ID | 20200630100546.862468-1-maz@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Chanwoo Choi |
| Headers | show |
| Series | [v3] PM / devfreq: rk3399_dmc: Fix kernel oops when rockchip,pmu is absent | expand |
Hi Marc, On 6/30/20 7:05 PM, Marc Zyngier wrote: > Booting a recent kernel on a rk3399-based system (nanopc-t4), > equipped with a recent u-boot and ATF results in an Oops due > to a NULL pointer dereference. > > This turns out to be due to the rk3399-dmc driver looking for > an *undocumented* property (rockchip,pmu), and happily using > a NULL pointer when the property isn't there. > > Instead, make most of what was brought in with 9173c5ceb035 > ("PM / devfreq: rk3399_dmc: Pass ODT and auto power down parameters > to TF-A.") conditioned on finding this property in the device-tree, > preventing the driver from exploding. > > Cc: stable@vger.kernel.org > Fixes: 9173c5ceb035 ("PM / devfreq: rk3399_dmc: Pass ODT and auto power down parameters to TF-A.") > Signed-off-by: Marc Zyngier <maz@kernel.org> > --- > * From v2: > - Trimmed down commit message > - Cc stable > > drivers/devfreq/rk3399_dmc.c | 42 ++++++++++++++++++++---------------- > 1 file changed, 23 insertions(+), 19 deletions(-) > > diff --git a/drivers/devfreq/rk3399_dmc.c b/drivers/devfreq/rk3399_dmc.c > index 24f04f78285b..027769e39f9b 100644 > --- a/drivers/devfreq/rk3399_dmc.c > +++ b/drivers/devfreq/rk3399_dmc.c > @@ -95,18 +95,20 @@ static int rk3399_dmcfreq_target(struct device *dev, unsigned long *freq, > > mutex_lock(&dmcfreq->lock); > > - if (target_rate >= dmcfreq->odt_dis_freq) > - odt_enable = true; > - > - /* > - * This makes a SMC call to the TF-A to set the DDR PD (power-down) > - * timings and to enable or disable the ODT (on-die termination) > - * resistors. > - */ > - arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, dmcfreq->odt_pd_arg0, > - dmcfreq->odt_pd_arg1, > - ROCKCHIP_SIP_CONFIG_DRAM_SET_ODT_PD, > - odt_enable, 0, 0, 0, &res); > + if (dmcfreq->regmap_pmu) { > + if (target_rate >= dmcfreq->odt_dis_freq) > + odt_enable = true; > + > + /* > + * This makes a SMC call to the TF-A to set the DDR PD > + * (power-down) timings and to enable or disable the > + * ODT (on-die termination) resistors. > + */ > + arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, dmcfreq->odt_pd_arg0, > + dmcfreq->odt_pd_arg1, > + ROCKCHIP_SIP_CONFIG_DRAM_SET_ODT_PD, > + odt_enable, 0, 0, 0, &res); > + } > > /* > * If frequency scaling from low to high, adjust voltage first. > @@ -371,13 +373,14 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev) > } > > node = of_parse_phandle(np, "rockchip,pmu", 0); > - if (node) { > - data->regmap_pmu = syscon_node_to_regmap(node); > - of_node_put(node); > - if (IS_ERR(data->regmap_pmu)) { > - ret = PTR_ERR(data->regmap_pmu); > - goto err_edev; > - } > + if (!node) > + goto no_pmu; > + > + data->regmap_pmu = syscon_node_to_regmap(node); > + of_node_put(node); > + if (IS_ERR(data->regmap_pmu)) { > + ret = PTR_ERR(data->regmap_pmu); > + goto err_edev; > } > > regmap_read(data->regmap_pmu, RK3399_PMUGRF_OS_REG2, &val); > @@ -399,6 +402,7 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev) > goto err_edev; > }; > > +no_pmu: > arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, 0, 0, > ROCKCHIP_SIP_CONFIG_DRAM_INIT, > 0, 0, 0, 0, &res); > Applied it. Thanks.
diff --git a/drivers/devfreq/rk3399_dmc.c b/drivers/devfreq/rk3399_dmc.c index 24f04f78285b..027769e39f9b 100644 --- a/drivers/devfreq/rk3399_dmc.c +++ b/drivers/devfreq/rk3399_dmc.c @@ -95,18 +95,20 @@ static int rk3399_dmcfreq_target(struct device *dev, unsigned long *freq, mutex_lock(&dmcfreq->lock); - if (target_rate >= dmcfreq->odt_dis_freq) - odt_enable = true; - - /* - * This makes a SMC call to the TF-A to set the DDR PD (power-down) - * timings and to enable or disable the ODT (on-die termination) - * resistors. - */ - arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, dmcfreq->odt_pd_arg0, - dmcfreq->odt_pd_arg1, - ROCKCHIP_SIP_CONFIG_DRAM_SET_ODT_PD, - odt_enable, 0, 0, 0, &res); + if (dmcfreq->regmap_pmu) { + if (target_rate >= dmcfreq->odt_dis_freq) + odt_enable = true; + + /* + * This makes a SMC call to the TF-A to set the DDR PD + * (power-down) timings and to enable or disable the + * ODT (on-die termination) resistors. + */ + arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, dmcfreq->odt_pd_arg0, + dmcfreq->odt_pd_arg1, + ROCKCHIP_SIP_CONFIG_DRAM_SET_ODT_PD, + odt_enable, 0, 0, 0, &res); + } /* * If frequency scaling from low to high, adjust voltage first. @@ -371,13 +373,14 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev) } node = of_parse_phandle(np, "rockchip,pmu", 0); - if (node) { - data->regmap_pmu = syscon_node_to_regmap(node); - of_node_put(node); - if (IS_ERR(data->regmap_pmu)) { - ret = PTR_ERR(data->regmap_pmu); - goto err_edev; - } + if (!node) + goto no_pmu; + + data->regmap_pmu = syscon_node_to_regmap(node); + of_node_put(node); + if (IS_ERR(data->regmap_pmu)) { + ret = PTR_ERR(data->regmap_pmu); + goto err_edev; } regmap_read(data->regmap_pmu, RK3399_PMUGRF_OS_REG2, &val); @@ -399,6 +402,7 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev) goto err_edev; }; +no_pmu: arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, 0, 0, ROCKCHIP_SIP_CONFIG_DRAM_INIT, 0, 0, 0, 0, &res);
Booting a recent kernel on a rk3399-based system (nanopc-t4), equipped with a recent u-boot and ATF results in an Oops due to a NULL pointer dereference. This turns out to be due to the rk3399-dmc driver looking for an *undocumented* property (rockchip,pmu), and happily using a NULL pointer when the property isn't there. Instead, make most of what was brought in with 9173c5ceb035 ("PM / devfreq: rk3399_dmc: Pass ODT and auto power down parameters to TF-A.") conditioned on finding this property in the device-tree, preventing the driver from exploding. Cc: stable@vger.kernel.org Fixes: 9173c5ceb035 ("PM / devfreq: rk3399_dmc: Pass ODT and auto power down parameters to TF-A.") Signed-off-by: Marc Zyngier <maz@kernel.org> --- * From v2: - Trimmed down commit message - Cc stable drivers/devfreq/rk3399_dmc.c | 42 ++++++++++++++++++++---------------- 1 file changed, 23 insertions(+), 19 deletions(-)