Hi Matthias
On 4/2/2020 1:16 AM, Matthias Kaehlcke wrote:
On Tue, Mar 31, 2020 at 11:24:57AM -0700, Matthias Kaehlcke wrote:
Hi Akash,
On Tue, Mar 31, 2020 at 04:39:31PM +0530, Akash Asthana wrote:
QUP core clock is shared among all the SE drivers present on particular
QUP wrapper, the system will reset(unclocked access) if earlycon used after
QUP core clock is put to 0 from other SE drivers before real console comes
up.
As earlycon can't vote for it's QUP core need, to fix this add ICC
support to common/QUP wrapper driver and put vote for QUP core from
probe on behalf of earlycon and remove vote during earlycon exit call.
Signed-off-by: Akash Asthana <akashast@xxxxxxxxxxxxxx>
Reported-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
---
Change is V3:
- Add geni_remove_earlycon_icc_vote API that will be used by earlycon
exit function to remove ICC vote for earlyconsole.
- Remove suspend/resume hook for geni-se driver as we are no longer
removing earlyconsole ICC vote from system suspend, we are removing
from earlycon exit.
drivers/soc/qcom/qcom-geni-se.c | 51 +++++++++++++++++++++++++++++++++++
drivers/tty/serial/qcom_geni_serial.c | 7 +++++
include/linux/qcom-geni-se.h | 2 ++
3 files changed, 60 insertions(+)
diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c
index 9344c14..d30c282 100644
--- a/drivers/soc/qcom/qcom-geni-se.c
+++ b/drivers/soc/qcom/qcom-geni-se.c
@@ -90,8 +90,11 @@ struct geni_wrapper {
struct device *dev;
void __iomem *base;
struct clk_bulk_data ahb_clks[NUM_AHB_CLKS];
+ struct geni_icc_path to_core;
};
+struct geni_wrapper *earlycon_wrapper;
should be static
Yeah ok, I missed it.
+
#define QUP_HW_VER_REG 0x4
/* Common SE registers */
@@ -818,6 +821,26 @@ int geni_icc_vote_off(struct geni_se *se)
}
EXPORT_SYMBOL(geni_icc_vote_off);
+void geni_remove_earlycon_icc_vote(void)
+{
+ struct geni_wrapper *wrapper = earlycon_wrapper;
+ struct device_node *parent = of_get_next_parent(wrapper->dev->of_node);
+ struct device_node *child;
+
+ for_each_child_of_node(parent, child) {
+ if (of_device_is_compatible(child, "qcom,geni-se-qup")) {
+ wrapper = platform_get_drvdata(of_find_device_by_node(
+ child));
+ icc_put(wrapper->to_core.path);
+ wrapper->to_core.path = NULL;
+ }
+ }
+ of_node_put(parent);
+
+ earlycon_wrapper = NULL;
+}
+EXPORT_SYMBOL(geni_remove_earlycon_icc_vote);
I didn't know that consoles have an exit handler, this is way nicer than
the miscellaneous triggers we discussed earlier :)
No wonder I 'missed' this when looking at the console code for possible
triggers, it is brand new and as of now only exists in -next:
commit ed31685c96e18f773ca11dd1a637974d62130673
Author: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Date: Mon Feb 3 15:31:30 2020 +0200
console: Introduce ->exit() callback
sharp timing!
Yeah this is added recently, even I was not aware of it, Bjorn suggested
me to use this. Indeed sharp timing! :)
Regards,
Akash
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