kernel.git/drivers/net/ipa/ipa_endpoint.c, branch linux-5.16.y

net: ipa: prevent concurrent replenish

2022-02-05T11:39:54Z

commit 998c0bd2b3715244da7639cc4e6a2062cb79c3f4 upstream. We have seen cases where an endpoint RX completion interrupt arrives while replenishing for the endpoint is underway. This causes another instance of replenishing to begin as part of completing the receive transaction. If this occurs it can lead to transaction corruption. Use a new flag to ensure only one replenish instance for an endpoint executes at a time. Fixes: 84f9bd12d46db ("soc: qcom: ipa: IPA endpoints") Signed-off-by: Alex Elder Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: ipa: use a bitmap for endpoint replenish_enabled

2022-02-05T11:39:54Z

commit c1aaa01dbf4cef95af3e04a5a43986c290e06ea3 upstream. Define a new replenish_flags bitmap to contain Boolean flags associated with an endpoint's replenishing state. Replace the replenish_enabled field with a flag in that bitmap. This is to prepare for the next patch, which adds another flag. Signed-off-by: Alex Elder Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: ipa: fix atomic update in ipa_endpoint_replenish()

2022-01-27T11:03:01Z

commit 6c0e3b5ce94947b311348c367db9e11dcb2ccc93 upstream. In ipa_endpoint_replenish(), if an error occurs when attempting to replenish a receive buffer, we just quit and try again later. In that case we increment the backlog count to reflect that the attempt was unsuccessful. Then, if the add_one flag was true we increment the backlog again. This second increment is not included in the backlog local variable though, and its value determines whether delayed work should be scheduled. This is a bug. Fix this by determining whether 1 or 2 should be added to the backlog before adding it in a atomic_add_return() call. Reviewed-by: Matthias Kaehlcke Fixes: 84f9bd12d46db ("soc: qcom: ipa: IPA endpoints") Signed-off-by: Alex Elder Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: ipa: kill ipa_cmd_pipeline_clear()

2021-11-23T12:26:40Z

Calling ipa_cmd_pipeline_clear() after stopping the channel underlying the AP<-modem RX endpoint can lead to a deadlock. This occurs in the ->runtime_suspend device power operation for the IPA driver. While this callback is in progress, any other requests for power will block until the callback returns. Stopping the AP<-modem RX channel does not prevent the modem from sending another packet to this endpoint. If a packet arrives for an RX channel when the channel is stopped, an SUSPEND IPA interrupt condition will be pending. Handling an IPA interrupt requires power, so ipa_isr_thread() calls pm_runtime_get_sync() first thing. The problem occurs because a "pipeline clear" command will not complete while such a SUSPEND interrupt condition exists. So the SUSPEND IPA interrupt handler won't proceed until it gets power; that won't happen until the ->runtime_suspend callback (and its "pipeline clear" command) completes; and that can't happen while the SUSPEND interrupt condition exists. It turns out that in this case there is no need to use the "pipeline clear" command. There are scenarios in which clearing the pipeline is required while suspending, but those are not (yet) supported upstream. So a simple fix, avoiding the potential deadlock, is to stop calling ipa_cmd_pipeline_clear() in ipa_endpoint_suspend(). This removes the only user of ipa_cmd_pipeline_clear(), so get rid of that function. It can be restored again whenever it's needed. This is basically a manual revert along with an explanation for commit 6cb63ea6a39ea ("net: ipa: introduce ipa_cmd_tag_process()"). Fixes: 6cb63ea6a39ea ("net: ipa: introduce ipa_cmd_tag_process()") Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: disable HOLB drop when updating timer

2021-11-15T13:25:45Z

The head-of-line blocking timer should only be modified when head-of-line drop is disabled. One of the steps in recovering from a modem crash is to enable dropping of packets with timeout of 0 (immediate). We don't know how the modem configured its endpoints, so before we program the timer, we need to ensure HOL_BLOCK is disabled. Fixes: 84f9bd12d46db ("soc: qcom: ipa: IPA endpoints") Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: HOLB register sometimes must be written twice

2021-11-15T13:25:45Z

Starting with IPA v4.5, the HOL_BLOCK_EN register must be written twice when enabling head-of-line blocking avoidance. Fixes: 84f9bd12d46db ("soc: qcom: ipa: IPA endpoints") Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: rename "ipa_clock.c"

2021-08-22T08:44:17Z

Finally, rename "ipa_clock.c" to be "ipa_power.c" and "ipa_clock.h" to be "ipa_power.h". Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: rename ipa_clock_* symbols

2021-08-22T08:44:17Z

Rename a number of functions to clarify that there is no longer a notion of an "IPA clock," but rather that the functions are more generally related to IPA power management. ipa_clock_enable() -> ipa_power_enable() ipa_clock_disable() -> ipa_power_disable() ipa_clock_rate() -> ipa_core_clock_rate() ipa_clock_init() -> ipa_power_init() ipa_clock_exit() -> ipa_power_exit() Rename the ipa_clock structure to be ipa_power. Rename all variables and fields using that structure type "power" rather than "clock". Rename the ipa_clock_data structure to be ipa_power_data, and more broadly, just substitute "power" for "clock" in places that previously represented things related to the "IPA clock". Update comments throughout. Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: use gsi->version for channel suspend/resume

2021-08-04T09:12:05Z

The GSI layer has the IPA version now, so there's no need for version-specific flags to be passed from IPA. One instance of this is in gsi_channel_suspend() and gsi_channel_resume(), which indicate whether or not the endpoint suspend is implemented by GSI stopping the channel. We can make that determination based on gsi->version, eliminating the need for a Boolean flag in those functions. Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: use WARN_ON() rather than assertions

2021-07-26T21:38:11Z

I've added commented assertions to record certain properties that can be assumed to hold in certain places in the IPA code. Convert these into real WARN_ON() calls so the assertions are actually checked, using the standard WARN_ON() mechanism. Where errors can be returned, return an error if a warning is triggered. Signed-off-by: Alex Elder Signed-off-by: David S. Miller