On 4/27/22 3:52 PM, Georgi Djakov wrote:
On 27.04.22 15:00, Alex Elder wrote:
On 4/26/22 8:32 PM, Stephen Boyd wrote:
Ignore compatible strings for the IPA virt drivers that were removed in
commits 2fb251c26560 ("interconnect: qcom: sdx55: Drop IP0
interconnects") and 2f3724930eb4 ("interconnect: qcom: sc7180: Drop IP0
interconnects") so that the sync state logic can kick in again.
Otherwise all the interconnects in the system will stay pegged at max
speeds because 'providers_count' is always going to be one larger than
the number of drivers that will ever probe on sc7180 or sdx55. This
fixes suspend on sc7180 and sdx55 devices when you don't have a
devicetree patch to remove the ipa-virt compatible node.
Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Cc: Doug Anderson <dianders@xxxxxxxxxxxx>
Cc: Alex Elder <elder@xxxxxxxxxx>
Cc: Taniya Das <quic_tdas@xxxxxxxxxxx>
Cc: Mike Tipton <quic_mdtipton@xxxxxxxxxxx>
Fixes: 2fb251c26560 ("interconnect: qcom: sdx55: Drop IP0
interconnects")
Fixes: 2f3724930eb4 ("interconnect: qcom: sc7180: Drop IP0
interconnects")
Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
So of_count_icc_providers() counts the number of
interconnect providers defined in the DTB, regardless
of whether anything in the code supports it.
Yes, that's the case currently. There could be multiple provider drivers
in different modules, and the modules may be loaded even not during boot,
but later. So we rely on DT.
Georgi, do you have any other ideas about how to improve this?
What you say makes sense--you figure out the total number of
providers at init time based on what's defined in DT.
But when all is said and done, what if even *one* of those
has no provider driver? Isn't that what causes the problem
here, that icc_sync_state assumes all providers specified in
DT will eventually have a driver that calls icc_sync_state()?
(I don't claim to know the interconnect code in detail, so
I might not be quite understanding how this works.)
-Alex
Thanks,
Georgi
This seems to be a more general problem, but I
suppose in practice it's not likely to occur.
I think your solution looks fine, but I'm interested
in what Georgi has to say.
Reviewed-by: Alex Elder <elder@xxxxxxxxxx>
---
drivers/interconnect/core.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index 9050ca1f4285..c52915a58b22 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -1087,9 +1087,15 @@ static int of_count_icc_providers(struct
device_node *np)
{
struct device_node *child;
int count = 0;
+ const struct of_device_id ignore_list[] = {
+ { .compatible = "qcom,sc7180-ipa-virt" },
+ { .compatible = "qcom,sdx55-ipa-virt" },
+ {}
+ };
for_each_available_child_of_node(np, child) {
- if (of_property_read_bool(child, "#interconnect-cells"))
+ if (of_property_read_bool(child, "#interconnect-cells") &&
+ likely(!of_match_node(ignore_list, child)))
count++;
count += of_count_icc_providers(child);
}
base-commit: 2fb251c265608636fc961b7d38e1a03937e57371
