linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Alex Elder <elder@linaro.org>
To: davem@davemloft.net, kuba@kernel.org
Cc: evgreen@chromium.org, bjorn.andersson@linaro.org,
	cpratapa@codeaurora.org, subashab@codeaurora.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH net 1/2] net: ipa: introduce atomic channel STOPPING flag
Date: Thu,  7 Jan 2021 15:43:24 -0600	[thread overview]
Message-ID: <20210107214325.7077-2-elder@linaro.org> (raw)
In-Reply-To: <20210107214325.7077-1-elder@linaro.org>

Introduce a new atomic flag bit to communicate that a channel is
stopping.  At the end of the NAPI poll loop, we normally re-enable
the IEOB interrupt, but now we won't do that if the channel is being
stopped.  This is required for the next patch.

Fixes: 650d1603825d8 ("soc: qcom: ipa: the generic software interface")
Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/gsi.c | 11 ++++++++++-
 drivers/net/ipa/gsi.h |  6 ++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c
index 14d9a791924bf..7e7629902911e 100644
--- a/drivers/net/ipa/gsi.c
+++ b/drivers/net/ipa/gsi.c
@@ -739,6 +739,10 @@ static void gsi_channel_freeze(struct gsi_channel *channel)
 {
 	gsi_channel_trans_quiesce(channel);
 
+	/* Don't let the NAPI poll loop re-enable interrupts when done */
+	set_bit(GSI_CHANNEL_FLAG_STOPPING, channel->flags);
+	smp_mb__after_atomic();	/* Ensure gsi_channel_poll() sees new value */
+
 	napi_disable(&channel->napi);
 
 	gsi_irq_ieob_disable(channel->gsi, channel->evt_ring_id);
@@ -749,6 +753,10 @@ static void gsi_channel_thaw(struct gsi_channel *channel)
 {
 	gsi_irq_ieob_enable(channel->gsi, channel->evt_ring_id);
 
+	/* Allow the NAPI poll loop to re-enable interrupts again */
+	clear_bit(GSI_CHANNEL_FLAG_STOPPING, channel->flags);
+	smp_mb__after_atomic();	/* Ensure gsi_channel_poll() sees new value */
+
 	napi_enable(&channel->napi);
 }
 
@@ -1536,7 +1544,8 @@ static int gsi_channel_poll(struct napi_struct *napi, int budget)
 
 	if (count < budget) {
 		napi_complete(&channel->napi);
-		gsi_irq_ieob_enable(channel->gsi, channel->evt_ring_id);
+		if (!test_bit(GSI_CHANNEL_FLAG_STOPPING, channel->flags))
+			gsi_irq_ieob_enable(channel->gsi, channel->evt_ring_id);
 	}
 
 	return count;
diff --git a/drivers/net/ipa/gsi.h b/drivers/net/ipa/gsi.h
index 96c9aed397aad..8f0ae97c80c6e 100644
--- a/drivers/net/ipa/gsi.h
+++ b/drivers/net/ipa/gsi.h
@@ -104,9 +104,15 @@ enum gsi_channel_state {
 	GSI_CHANNEL_STATE_ERROR			= 0xf,
 };
 
+enum gsi_channel_flag {
+	GSI_CHANNEL_FLAG_STOPPING,
+	GSI_CHANNEL_FLAG_COUNT,		/* Last; not a flag */
+};
+
 /* We only care about channels between IPA and AP */
 struct gsi_channel {
 	struct gsi *gsi;
+	DECLARE_BITMAP(flags, GSI_CHANNEL_FLAG_COUNT);
 	bool toward_ipa;
 	bool command;			/* AP command TX channel or not */
 
-- 
2.20.1


  reply	other threads:[~2021-01-07 21:44 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-07 21:43 [PATCH net 0/2] net: ipa: fix a suspend hang Alex Elder
2021-01-07 21:43 ` Alex Elder [this message]
2021-01-07 21:43 ` [PATCH net 2/2] net: ipa: re-enable NAPI before enabling interrupt Alex Elder
2021-01-08  2:38   ` Jakub Kicinski
2021-01-08 20:16     ` Alex Elder

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210107214325.7077-2-elder@linaro.org \
    --to=elder@linaro.org \
    --cc=bjorn.andersson@linaro.org \
    --cc=cpratapa@codeaurora.org \
    --cc=davem@davemloft.net \
    --cc=evgreen@chromium.org \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=subashab@codeaurora.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).