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PM / devfreq: rk3399_dmc: Fix kernel oops when rockchip,pmu is absent 

[ Upstream commit 63ef91f24f9bfc70b6446319f6cabfd094481372 ]

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 9173c5ceb0
("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: 9173c5ceb0 ("PM / devfreq: rk3399_dmc: Pass ODT and auto power down parameters to TF-A.")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Marc Zyngier 2020-06-30 11:05:46 +01:00 committed by Greg Kroah-Hartman
parent b7cca731b4
commit fe376f1b12
1 changed files with 22 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
drivers/devfreq/rk3399_dmc.c
View File

@ -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;
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);
/*
* 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);