From: Alex Elder <elder@linaro.org>
To: davem@davemloft.net, kuba@kernel.org
Cc: evgreen@chromium.org, cpratapa@codeaurora.org,
bjorn.andersson@linaro.org, subashab@codeaurora.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH net 2/3] net: ipa: use state to determine channel command success
Date: Tue, 22 Dec 2020 12:00:11 -0600 [thread overview]
Message-ID: <20201222180012.22489-3-elder@linaro.org> (raw)
In-Reply-To: <20201222180012.22489-1-elder@linaro.org>
The result of issuing a channel control command should be that the
channel changes state. If enabled, a completion interrupt signals
that the channel state has changed. This interrupt is enabled by
gsi_channel_command() and disabled again after the command has
completed (or we time out).
There is a window of time--after the completion interrupt is disabled
but before the channel state is read--during which the command could
complete successfully without interrupting. This would cause the
channel to transition to the desired new state.
So whether a channel command ends via completion interrupt or
timeout, we can consider the command successful if the channel
has entered the desired state (and a failure if it has not,
regardless of the cause).
Fixes: d6c9e3f506ae8 ("net: ipa: only enable generic command completion IRQ when needed");
Signed-off-by: Alex Elder <elder@linaro.org>
---
drivers/net/ipa/gsi.c | 43 ++++++++++++++++++++++---------------------
1 file changed, 22 insertions(+), 21 deletions(-)
diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c
index 4aee60d62ab09..4f0e791764237 100644
--- a/drivers/net/ipa/gsi.c
+++ b/drivers/net/ipa/gsi.c
@@ -505,15 +505,15 @@ static int gsi_channel_alloc_command(struct gsi *gsi, u32 channel_id)
ret = gsi_channel_command(channel, GSI_CH_ALLOCATE);
- /* Channel state will normally have been updated */
+ /* If successful the channel state will have changed */
state = gsi_channel_state(channel);
- if (!ret && state != GSI_CHANNEL_STATE_ALLOCATED) {
- dev_err(dev, "channel %u bad state %u after alloc\n",
- channel_id, state);
- ret = -EIO;
- }
+ if (state == GSI_CHANNEL_STATE_ALLOCATED)
+ return 0;
- return ret;
+ dev_err(dev, "channel %u bad state %u after alloc\n",
+ channel_id, state);
+
+ return -EIO;
}
/* Start an ALLOCATED channel */
@@ -533,15 +533,15 @@ static int gsi_channel_start_command(struct gsi_channel *channel)
ret = gsi_channel_command(channel, GSI_CH_START);
- /* Channel state will normally have been updated */
+ /* If successful the channel state will have changed */
state = gsi_channel_state(channel);
- if (!ret && state != GSI_CHANNEL_STATE_STARTED) {
- dev_err(dev, "channel %u bad state %u after start\n",
- gsi_channel_id(channel), state);
- ret = -EIO;
- }
+ if (state == GSI_CHANNEL_STATE_STARTED)
+ return 0;
- return ret;
+ dev_err(dev, "channel %u bad state %u after start\n",
+ gsi_channel_id(channel), state);
+
+ return -EIO;
}
/* Stop a GSI channel in STARTED state */
@@ -568,10 +568,10 @@ static int gsi_channel_stop_command(struct gsi_channel *channel)
ret = gsi_channel_command(channel, GSI_CH_STOP);
- /* Channel state will normally have been updated */
+ /* If successful the channel state will have changed */
state = gsi_channel_state(channel);
- if (ret || state == GSI_CHANNEL_STATE_STOPPED)
- return ret;
+ if (state == GSI_CHANNEL_STATE_STOPPED)
+ return 0;
/* We may have to try again if stop is in progress */
if (state == GSI_CHANNEL_STATE_STOP_IN_PROC)
@@ -604,9 +604,9 @@ static void gsi_channel_reset_command(struct gsi_channel *channel)
ret = gsi_channel_command(channel, GSI_CH_RESET);
- /* Channel state will normally have been updated */
+ /* If successful the channel state will have changed */
state = gsi_channel_state(channel);
- if (!ret && state != GSI_CHANNEL_STATE_ALLOCATED)
+ if (state != GSI_CHANNEL_STATE_ALLOCATED)
dev_err(dev, "channel %u bad state %u after reset\n",
gsi_channel_id(channel), state);
}
@@ -628,9 +628,10 @@ static void gsi_channel_de_alloc_command(struct gsi *gsi, u32 channel_id)
ret = gsi_channel_command(channel, GSI_CH_DE_ALLOC);
- /* Channel state will normally have been updated */
+ /* If successful the channel state will have changed */
state = gsi_channel_state(channel);
- if (!ret && state != GSI_CHANNEL_STATE_NOT_ALLOCATED)
+
+ if (state != GSI_CHANNEL_STATE_NOT_ALLOCATED)
dev_err(dev, "channel %u bad state %u after dealloc\n",
channel_id, state);
}
--
2.20.1
next prev parent reply other threads:[~2020-12-22 18:01 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-22 18:00 [PATCH net 0/3] net: ipa: GSI interrupt handling fixes Alex Elder
2020-12-22 18:00 ` [PATCH net 1/3] net: ipa: clear pending interrupts before enabling Alex Elder
2020-12-22 18:00 ` Alex Elder [this message]
2020-12-26 18:51 ` [PATCH net 2/3] net: ipa: use state to determine channel command success kernel test robot
2020-12-22 18:00 ` [PATCH net 3/3] net: ipa: use state to determine event ring " Alex Elder
2020-12-23 20:20 ` [PATCH net 0/3] net: ipa: GSI interrupt handling fixes patchwork-bot+netdevbpf
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=20201222180012.22489-3-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).