Re: [PATCH] venus: pm_helpers: Fix kernel module reload

From: Rajendra Nayak
Date: Tue Nov 03 2020 - 08:28:30 EST



On 11/1/2020 6:30 PM, Stanimir Varbanov wrote:
After initial kernel module load during kernel boot and removing
the module and try to load it again an Unable to handle kernel
paging request is observed:

Unable to handle kernel paging request at virtual address ffffa44f7416eae0
Mem abort info:
ESR = 0x96000047
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
Data abort info:
ISV = 0, ISS = 0x00000047
CM = 0, WnR = 1
swapper pgtable: 4k pages, 48-bit VAs, pgdp=000000008147c000
[ffffa44f7416eae0] pgd=000000017df9f003, p4d=000000017df9f003,
pud=000000017df9e003, pmd=000000017df9b003, pte=0000000000000000
Internal error: Oops: 96000047 [#1] PREEMPT SMP
Modules linked in: venus_core(+) snd_soc_wsa881x regmap_sdw af_alg
snd_soc_wcd934x soundwire_qcom gpio_wcd934x q6asm_dai q6routing
q6adm q6afe_dai snd_soc_hdmi_codec q6afe q6asm q6dsp_common q6cor
display_connector rmtfs_mem drm ip_tables x_tables ipv6
[last unloaded: venus_core]
CPU: 6 PID: 889 Comm: modprobe Tainted: G W 5.10.0-rc1+ #8
Hardware name: Thundercomm Dragonboard 845c (DT)
pstate: 80400085 (Nzcv daIf +PAN -UAO -TCO BTYPE=--)
pc : queued_spin_lock_slowpath+0x1dc/0x3c8
lr : do_raw_spin_lock+0xc0/0x118
sp : ffff8000142cb7b0
x29: ffff8000142cb7b0 x28: 0000000000000013
x27: ffffa44f72de5690 x26: 0000000000000003
x25: ffff17c2d00f8080 x24: ffff17c2c0d78010
x23: ffff17c2c0d4f700 x22: ffff17c2d00f8080
x21: 0000000000000000 x20: ffffa44f74148000
x19: ffff17c2c0d4f8f8 x18: 0000000000000000
x17: 0000000000000000 x16: ffffa44f7342f158
x15: 0000000000000040 x14: ffffa44f746e8320
x13: 0000000000000228 x12: 0000000000000020
x11: 0000000000000000 x10: 00000000001c0000
x9 : 0000000000000000 x8 : ffff17c33d746ac0
x7 : ffff17c2c109b000 x6 : ffffa44f7416eac0
x5 : ffff17c33d746ac0 x4 : 0000000000000000
x3 : ffff17c2c0d4f8f8 x2 : ffffa44f7416eae0
x1 : ffffa44f7416eae0 x0 : ffff17c33d746ac8
Call trace:
queued_spin_lock_slowpath+0x1dc/0x3c8
do_raw_spin_lock+0xc0/0x118
_raw_spin_lock_irqsave+0x80/0x14c
__pm_runtime_resume+0x38/0xb8
device_link_add+0x3b8/0x5d0
core_get_v4+0x268/0x2d8 [venus_core]
venus_probe+0x108/0x458 [venus_core]
platform_drv_probe+0x54/0xa8
really_probe+0xe4/0x3b0
driver_probe_device+0x58/0xb8
device_driver_attach+0x74/0x80
__driver_attach+0x58/0xe8
bus_for_each_dev+0x70/0xc0
driver_attach+0x24/0x30
bus_add_driver+0x150/0x1f8
driver_register+0x64/0x120
__platform_driver_register+0x48/0x58
qcom_venus_driver_init+0x20/0x1000 [venus_core]
do_one_initcall+0x84/0x458
do_init_module+0x58/0x208
load_module+0x1ec0/0x26a8
__do_sys_finit_module+0xb8/0xf8
__arm64_sys_finit_module+0x20/0x30
el0_svc_common.constprop.0+0x7c/0x1c0
do_el0_svc+0x24/0x90
el0_sync_handler+0x180/0x188
el0_sync+0x174/0x180
Code: 91002100 8b0200c2 f861d884 aa0203e1 (f8246828)
---[ end trace f1f687c15fd6b2ca ]---
note: modprobe[889] exited with preempt_count 1

After revisit the OPP part of the code I found that OPP pmdomain
is detached with direct call to dev_pm_domain_detach instead of
OPP wraper for detaching pmdomains with OPP table. Correct this
by calling the OPP dev_pm_opp_detach_genpd.

ah, that seems like the right thing to do. Sorry, looks like I hadn't
really tested the cleanup path by loading/unloading the module :/

Reviewed-by: Rajendra Nayak <rnayak@xxxxxxxxxxxxxx>


Fixes: 9a538b83612c ('media: venus: core: Add support for opp tables/perf voting')
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@xxxxxxxxxx>
---
drivers/media/platform/qcom/venus/pm_helpers.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/qcom/venus/pm_helpers.c b/drivers/media/platform/qcom/venus/pm_helpers.c
index 0ebba8e3bd75..2946547a0df4 100644
--- a/drivers/media/platform/qcom/venus/pm_helpers.c
+++ b/drivers/media/platform/qcom/venus/pm_helpers.c
@@ -804,7 +804,7 @@ static int vcodec_domains_get(struct device *dev)
return 0;
opp_dl_add_err:
- dev_pm_domain_detach(core->opp_pmdomain, true);
+ dev_pm_opp_detach_genpd(core->opp_table);
opp_attach_err:
if (core->pd_dl_venus) {
device_link_del(core->pd_dl_venus);
@@ -842,7 +842,7 @@ static void vcodec_domains_put(struct device *dev)
if (core->opp_dl_venus)
device_link_del(core->opp_dl_venus);
- dev_pm_domain_detach(core->opp_pmdomain, true);
+ dev_pm_opp_detach_genpd(core->opp_table);
}
static int core_get_v4(struct device *dev)


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