On Mon 30 Mar 02:49 PDT 2020, Manivannan Sadhasivam wrote:

Hi Chris,

On Thu, Mar 26, 2020 at 03:54:42PM -0700, Chris Lew wrote:

quoted

On 3/25/2020 3:37 AM, Manivannan Sadhasivam wrote:

quoted

Hi Bjorn,

+ Chris Lew

On Tue, Mar 24, 2020 at 01:39:52PM -0700, Bjorn Andersson wrote:

quoted

On Mon 23 Mar 23:10 PDT 2020, Manivannan Sadhasivam wrote:

[..]

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+	spin_lock_irqsave(&qdev->ul_lock, flags);
+	list_for_each_entry(pkt, &qdev->ul_pkts, node)
+		complete_all(&pkt->done);

Chris, shouldn't we require list_del(&pkt->node) here?

No this isn't a full cleanup, with the "early notifier" we just unblocked
any threads waiting for the ul_callback. Those threads will wake, check
in_reset, return an error back to the caller. Any list cleanup will be done
in the ul_callbacks that the mhi bus will do for each queued packet right
before device remove.

Again to simplify the code, we can probable remove the in_reset handling
since it's not required with the current feature set.

So since we are not getting status_cb for fatal errors, I think we should just
remove status_cb, in_reset and timeout code.

Looks reasonable.

[..]

quoted

I thought having the client get an error on timeout and resend the packet
would be better than silently dropping it. In practice, we've really only
seen the timeout or ul_callback errors on unrecoverable errors so I think
the timeout handling can definitely be redone.

You mean we can just remove the timeout handling part and return after
kref_put()?

If all messages are "generated" by qcom_mhi_qrtr_send() and "released"
in qcom_mhi_qrtr_ul_callback() I don't think you need the refcounting at
all.


Presumably though, it would have been nice to not have to carry a
separate list of packets (and hope that it's in sync with the mhi core)
and instead have the ul callback somehow allow us to derive the skb to
be freed.

Regards,
Bjorn