[RFC] Wake HW serial device up before reading #18
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
nicovanduijn
requested review from
bkueng,
DanielePettenuzzo,
caleridas and
MatejFranceskin
|
No, this is not normal and a BSP / DRIVER issue. |
|
what controller does the 845 feature? Docs do not state... both this issue and the latency problems are solvable for certain, but I am unclear about prio (or whether USB is preferred anyways). |
|
I don't know how to answer that question. What do you mean by controller? USB is not an option, the board is already manufactured |
|
after offline inspection, driver is here: https://patchwork.kernel.org/patch/10162069/ msm_geni_serial more precisely: https://github.com/torvalds/linux/blob/master/drivers/tty/serial/qcom_geni_serial.c |
MatejFranceskin
approved these changes
Aug 6, 2024
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
On the a Snapdragon 845 I have found that we do not get any data out of the serial device until a write to the same device occurs.
I currently don't understand if this is "normal" or due to some misconfiguration in the BSP. Either way, I'd appreciate some expertise and creative ideas on how to solve this problem in a nicer way than this PR does.
Note: on the same chip, same BSP, using an FTDI over USB works perfectly without this hack