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author | Shengjiu Wang <shengjiu.wang@nxp.com> | 2024-05-11 05:55:25 +0300 |
---|---|---|
committer | Ulf Hansson <ulf.hansson@linaro.org> | 2024-05-21 13:21:01 +0300 |
commit | e8dc41afca161b988e6d462f4d0803d247e22250 (patch) | |
tree | 72c9ba26bd76540a4c80faf527e48cc9ea8930ae /drivers/pmdomain | |
parent | 8f6a15f095a63a83b096d9b29aaff4f0fbe6f6e6 (diff) | |
download | linux-e8dc41afca161b988e6d462f4d0803d247e22250.tar.xz |
pmdomain: imx: gpcv2: Add delay after power up handshake
AudioMix BLK-CTRL on i.MX8MP encountered an accessing register issue
after power up.
[ 2.181035] Kernel panic - not syncing: Asynchronous SError Interrupt
[ 2.181038] CPU: 1 PID: 48 Comm: kworker/u16:2 Not tainted 6.9.0-rc5-next-20240424-00003-g21cec88845c6 #171
[ 2.181047] Hardware name: NXP i.MX8MPlus EVK board (DT)
[ 2.181050] Workqueue: events_unbound deferred_probe_work_func
[ 2.181064] Call trace:
[...]
[ 2.181142] arm64_serror_panic+0x6c/0x78
[ 2.181149] do_serror+0x3c/0x70
[ 2.181157] el1h_64_error_handler+0x30/0x48
[ 2.181164] el1h_64_error+0x64/0x68
[ 2.181171] clk_imx8mp_audiomix_runtime_resume+0x34/0x44
[ 2.181183] __genpd_runtime_resume+0x30/0x80
[ 2.181195] genpd_runtime_resume+0x110/0x244
[ 2.181205] __rpm_callback+0x48/0x1d8
[ 2.181213] rpm_callback+0x68/0x74
[ 2.181224] rpm_resume+0x468/0x6c0
[ 2.181234] __pm_runtime_resume+0x50/0x94
[ 2.181243] pm_runtime_get_suppliers+0x60/0x8c
[ 2.181258] __driver_probe_device+0x48/0x12c
[ 2.181268] driver_probe_device+0xd8/0x15c
[ 2.181278] __device_attach_driver+0xb8/0x134
[ 2.181290] bus_for_each_drv+0x84/0xe0
[ 2.181302] __device_attach+0x9c/0x188
[ 2.181312] device_initial_probe+0x14/0x20
[ 2.181323] bus_probe_device+0xac/0xb0
[ 2.181334] deferred_probe_work_func+0x88/0xc0
[ 2.181344] process_one_work+0x150/0x290
[ 2.181357] worker_thread+0x2f8/0x408
[ 2.181370] kthread+0x110/0x114
[ 2.181381] ret_from_fork+0x10/0x20
[ 2.181391] SMP: stopping secondary CPUs
According to comments in power up handshake:
/* request the ADB400 to power up */
if (domain->bits.hskreq) {
regmap_update_bits(domain->regmap, domain->regs->hsk,
domain->bits.hskreq, domain->bits.hskreq);
/*
* ret = regmap_read_poll_timeout(domain->regmap, domain->regs->hsk, reg_val,
* (reg_val & domain->bits.hskack), 0,
* USEC_PER_MSEC);
* Technically we need the commented code to wait handshake. But that needs
* the BLK-CTL module BUS clk-en bit being set.
*
* There is a separate BLK-CTL module and we will have such a driver for it,
* that driver will set the BUS clk-en bit and handshake will be triggered
* automatically there. Just add a delay and suppose the handshake finish
* after that.
*/
}
The BLK-CTL module needs to add delay to wait for a handshake request finished.
For some BLK-CTL module (eg. AudioMix on i.MX8MP) doesn't have BUS clk-en
bit, it is better to add delay in this driver, as the BLK-CTL module doesn't
need to care about how it is powered up.
regmap_read_bypassed() is to make sure the above write IO transaction already
reaches target before udelay().
Fixes: 1496dd413b2e ("clk: imx: imx8mp: Add pm_runtime support for power saving")
Reported-by: Francesco Dolcini <francesco@dolcini.it>
Closes: https://lore.kernel.org/all/66293535.170a0220.21fe.a2e7@mx.google.com/
Suggested-by: Frank Li <frank.li@nxp.com>
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Tested-by: Adam Ford <aford173@gmail.com>
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/1715396125-3724-1-git-send-email-shengjiu.wang@nxp.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/pmdomain')
-rw-r--r-- | drivers/pmdomain/imx/gpcv2.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/pmdomain/imx/gpcv2.c b/drivers/pmdomain/imx/gpcv2.c index 4b828d74a606..856eaac0ec14 100644 --- a/drivers/pmdomain/imx/gpcv2.c +++ b/drivers/pmdomain/imx/gpcv2.c @@ -393,6 +393,17 @@ static int imx_pgc_power_up(struct generic_pm_domain *genpd) * automatically there. Just add a delay and suppose the handshake finish * after that. */ + + /* + * For some BLK-CTL module (eg. AudioMix on i.MX8MP) doesn't have BUS + * clk-en bit, it is better to add delay here, as the BLK-CTL module + * doesn't need to care about how it is powered up. + * + * regmap_read_bypassed() is to make sure the above write IO transaction + * already reaches target before udelay() + */ + regmap_read_bypassed(domain->regmap, domain->regs->hsk, ®_val); + udelay(5); } /* Disable reset clocks for all devices in the domain */ |