From 6ffddf3b3d182d886d754cfafdf909ccb14f464b Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Tue, 22 Dec 2020 12:00:11 -0600 Subject: [PATCH] net: ipa: use state to determine channel command success 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 Signed-off-by: Jakub Kicinski --- 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 4aee60d..4f0e791 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); } -- 2.7.4