Starting at IPA v5.0, the number of event rings per EE is defined
in a field in a new HW_PARAM_4 GSI register rather than HW_PARAM_2.
Define this new register and its fields, and update the code that
checks the number of rings supported by hardware to use the proper
field based on IPA version.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Starting with IPA v5.0, a channel's event ring index is encoded in
a field in the CH_C_CNTXT_1 GSI register rather than CH_C_CNTXT_0.
Define a new field ID for the former register and encode the event
ring in the appropriate register.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The GSI channel protocol field in the CH_C_CNTXT_0 GSI register is
widened starting IPA v5.0, making the CHTYPE_PROTOCOL_MSB field
added in IPA v4.5 unnecessary. Update the code to reflect this.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Now that we explicitly define each register field width there is no
need to have a special encoding function for the event ring length.
Add a field for this to the EV_CH_E_CNTXT_1 GSI register, and use it
in place of ev_ch_e_cntxt_1_length_encode() (which can be removed).
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Starting at IPA v4.5, almost all GSI registers had their offsets
changed by a fixed amount (shifted downward by 0xd000). Rather than
defining offsets for all those registers dependent on version, an
adjustment was applied for most register accesses. This was
implemented in commit cdeee49f3e ("net: ipa: adjust GSI register
addresses"). It was later modified to be a bit more obvious about
the adjusment, in commit 571b1e7e58 ("net: ipa: use a separate
pointer for adjusted GSI memory").
We now are able to define every GSI register with its own offset, so
there's no need to implement this special adjustment.
So get rid of the "virt_raw" pointer, and just maintain "virt" as
the (non-adjusted) base address of I/O mapped GSI register memory.
Redefine the offsets of all GSI registers (other than the INTER_EE
ones, which were not subject to the adjustment) for IPA v4.5+,
subtracting 0xd000 from their defined offsets instead.
Move the ERROR_LOG and ERROR_LOG_CLR definitions further down in the
register definition files so all registers are defined in order of
their offset.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
I spotted an error in a patch posted this week, unfortunately just
after it got accepted. The effect of the bug is that time-based
interrupt moderation is disabled. This is not technically a bug,
but it is not what is intended. The problem is that a |= assignment
got implemented as a simple assignment, so the previously assigned
value was ignored.
Fixes: edc6158b18 ("net: ipa: define fields for event-ring related registers")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Define field IDs for the remaining GSI registers, and populate the
register definition files accordingly. Use the reg_*() functions to
access field values for those regiters, and get rid of the previous
field definition constants.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Define field IDs for the EV_CH_E_CNTXT_0 and EV_CH_E_CNTXT_8 GSI
registers, and populate the register definition files accordingly.
Use the reg_*() functions to access field values for those regiters,
and get rid of the previous field definition constants.
The remaining EV_CH_E_CNTXT_* registers are written with full 32-bit
values (and have no fields).
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Beyond the CH_C_QOS register, two other registers whose offset is
related to channel number have fields within them.
Define the fields within the CH_C_CNTXT_0 GSI register, using an
enumerated type to identify the register's fields, and define an
array of field masks to use for that register's reg structure.
For the CH_C_CNTXT_1 GSI register, ch_c_cntxt_1_length_encode()
previously hid the difference in bit width in the channel ring
length field. Instead, define a new field CH_R_LENGTH and encode
the ring size with reg_encode().
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Define the fields within the CH_C_QOS GSI register using an array of
field masks in that register's reg structure. Use the reg functions
for encoding values in those fields.
One field in the register is present for IPA v4.0-4.2 only, two
others are present starting at IPA v4.5, and one more is there
starting at IPA v4.9.
Drop the "GSI_" prefix in symbols defined in the gsi_prefetch_mode
enumerated type, and define their values using decimal rather than
hexidecimal values.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add the remaining GSI register offset definitions. Use gsi_reg()
rather than the corresponding GSI_*_OFFSET() macros to get the
offsets for these registers, and get rid of the macros.
Note that we are now defining information for the HW_PARAM_2
register, and that doesn't appear until IPA v3.5.1.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add definitions of the offsets for IRQ-related GSI registers. Use
gsi_reg() rather than the corresponding GSI_CNTXT_*_OFFSET() macros
to get the offsets for these registers, and get rid of the macros.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add definitions of the offsets and strides for registers whose
offset depends on an event ring ID, and use gsi_reg() and its
returned value to determine offsets for these registers. Get
rid of the corresponding GSI_EV_CH_E_*_OFFSET() macros.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Continue populating with GSI register definitions, adding remaining
registers whose offset depends on a channel ID. Use gsi_reg() and
reg_n_offset() to determine offsets for those registers, and get rid
of the corresponding GSI_CH_C_*_OFFSET() macros.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Create a new register definition file in the "reg" subdirectory,
and begin populating it with GSI register definitions based on IPA
version. The GSI registers haven't changed much, so several IPA
versions can share the same GSI register definitions.
As with IPA registers, an array of pointers indexed by GSI register ID
refers to these register definitions, and a new "regs" field in the
GSI structure is initialized in gsi_reg_init() to refer to register
information based on the IPA version (though for now there's only
one). The new function gsi_reg() returns register information for
a given GSI register, and the result can be used to look up that
register's offset.
This patch is meant only to put the infrastructure in place, so only
eon register (CH_C_QOS) is defined for each version, and only the
offset and stride are defined for that register. Use new function
gsi_reg() to look up that register's information to get its offset,
This makes the GSI_CH_C_QOS_OFFSET() unnecessary, so get rid of it.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Create a new source file "gsi_reg.c", and in it, introduce a new
function to encapsulate initializing GSI registers, including
looking up and I/O mapping their memory.
Create gsi_reg_exit() as the inverse of the init function.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move some static inline function definitions out of "gsi_reg.h" and
into "gsi.c", which is the only place they're used. Rename them so
their names identify the register they're associated with.
Move the gsi_channel_type enumerated type definition below the
offset and field definitions for the CH_C_CNTXT_0 register where
it's used.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are seven GSI interrupt types that can be signaled by a single
GSI IRQ. These are represented in a bitmask, and the gsi_irq_type_id
enumerated type defines what each bit position represents.
Similarly, the global and general GSI interrupt types each has a set
of conditions it signals, and both types have an enumerated type
that defines which bit that represents each condition.
When used, these enumerated values are passed as an argument to BIT()
in *all* cases. So clean up the code a little bit by defining the
enumerated type values as one-bit masks rather than bit positions.
Rename gsi_general_id to be gsi_general_irq_id for consistency.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Starting at IPA v4.11, the GSI_GENERIC_COMMAND GSI register got a
new PARAMS field. The code that encodes a value into that field
sets it unconditionally, which is wrong.
We currently only provide 0 as the field's value, so this error has
no real effect. Still, it's a bug, so let's fix it.
Fix an (unrelated) incorrect comment as well. Fields in the
ERROR_LOG GSI register actually *are* defined for IPA versions
prior to v3.5.1.
Fixes: fe68c43ce3 ("net: ipa: support enhanced channel flow control")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some source files state copyright dates that are earlier than the
last modification of the file. Change the copyright year to 2022 in
all such cases.
Signed-off-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20220930224549.3503434-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch just updates comments throughout the IPA code.
Transaction state is now tracked using indexes into an array rather
than linked lists, and a few comments refer to the "old way" of
doing things. The description of how transactions are used was
changed to refer to "operations" rather than "commands", to
(hopefully) remove a possible ambiguity.
IPA register offsets and fields are now handled differently as well,
and the register documentation is updated to better describe the
code.
A few minor updates to comments were made (e.g., adding a missing
word, fixing a typo or punctuation, etc.).
Finally, the local macro atomic_dec_not_zero() is no longer used, so
it is deleted.
Signed-off-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20220930224527.3503404-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We tell driver developers to always pass NAPI_POLL_WEIGHT
as the weight to netif_napi_add(). This may be confusing
to newcomers, drop the weight argument, those who really
need to tweak the weight can use netif_napi_add_weight().
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> # for CAN
Link: https://lore.kernel.org/r/20220927132753.750069-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
If it finds no completed transactions, gsi_channel_trans_complete()
calls gsi_channel_update() to check hardware. If new transactions
have completed, gsi_channel_update() records that, then calls
gsi_channel_trans_complete() to return the first of those found.
This recursion won't go any further, but can be avoided if we
have gsi_channel_update() only be responsible for updating state
after accessing hardware.
Change gsi_channel_update() so it simply checks for and handles
new completions, without returning a value. If it needs to call
that function, have gsi_channel_trans_complete() determine whether
there are new transactions available after the update.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Have gsi_channel_trans_complete() update the known state from
hardware rather than doing so in gsi_channel_poll_one().
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Do a little more refactoring in gsi_channel_trans_last() to simplify
it further. The resulting code should behave exactly as before.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Using a little logic we can simplify gsi_channel_trans_last().
The first condition in that function looks like this:
if (trans_info->allocated_id != trans_info->free_id)
And if that's false, we proceed to the next one:
if (trans_info->committed_id != trans_info->allocated_id)
Failure of the first test implies:
trans_info->allocated_id == trans_info->free_id
And therefore, the second one can be rewritten this way:
if (trans_info->committed_id != trans_info->free_id)
Substituting free_id for allocated_id and committed_id can also be
done in the code blocks executed when these conditions yield true.
The net result is that all three blocks for TX endpoints can be
consolidated into just one.
The two blocks of code at the end of that function (used for both TX
and RX channels) can be similarly consolidated into a single block.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Always use transaction IDs when finding the "last" transaction to
await when quiescing a channel. This basically extends what was
done in the previous patch to all other transaction state IDs.
As a result we are no longer updating any transaction lists inside
gsi_channel_trans_last(), so there's no need to take the spinlock.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use the allocated and free transaction IDs to determine whether the
"last" transaction used for quiescing a channel is in allocated
state. The last allocated transaction that has not been committed
(if any) immediately precedes the first free transaction in the
transaction array.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When quiescing a channel, we find the "last" transaction, which is
the latest one to have been allocated. (New transaction allocation
will have been prevented by the time this is called.)
Currently we do this by looking for the first non-empty transaction
list in each state, then return the last entry from that last.
Instead, determine the last entry in each list (if any) and return
that entry if found.
Temporarily (locally) introduce list_last_entry_or_null() as a
helper for this, mirroring list_first_entry_or_null(). This macro
definition will be removed by an upcoming patch.
Remove the temporary warnings added by the previous commit.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We currently put a transaction on the pending list when it has
been committed. But until the channel's doorbell rings, these
transactions aren't actually "owned" by the hardware yet.
Add a new "committed" state (and list), to represent transactions
that have been committed but not yet sent to hardware. Define
"pending" to mean committed transactions that have been sent
to hardware but have not yet completed.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When a GSI channel is initially allocated, and after it has been
reset, the hardware assumes its ring index is 0. And although we
do initialize channels this way, the comments in the IPA code don't
really explain this. For event rings, it doesn't matter what value
we use initially, so using 0 is just fine.
Add some information about the assumptions made by hardware above
the definition of the gsi_ring structure in "gsi.h".
Zero the index field for all rings (channel and event) when the ring
is allocated. As a result, that function initializes all fields in
the structure.
Stop zeroing the index the top of gsi_channel_program(). Initially
we'll use the index value set when the channel ring was allocated.
And we'll explicitly zero the index value in gsi_channel_reset()
before programming the hardware, adding a comment explaining why
it's required.
For event rings, use the index initialized by gsi_ring_alloc()
rather than 0 when ringing the doorbell in gsi_evt_ring_program().
(It'll still be zero, but we won't assume that to be the case.)
Use a local variable in gsi_evt_ring_program() that represents the
address of the event ring's ring structure.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move the processing done for TX channels in gsi_channel_update()
into gsi_evt_ring_rx_update(). The called function is called for
both RX and TX channels, so rename it to be gsi_evt_ring_update().
As a result, this code no longer assumes events in an event ring are
associated with just one channel.
Because all events in a ring are handled in that function, we can
move the call to gsi_trans_move_complete() there, and can ring the
event ring doorbell there as well after all new events in the ring
have been processed.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When an RX transaction completes, we update the trans->len field to
contain the actual number of bytes received. This is done in a loop
in gsi_evt_ring_rx_update().
Change that function so it checks the data transfer direction
recorded in the transaction, and only updates trans->len for RX
transfers.
Then call it unconditionally. This means events for TX endpoints
will run through the loop without otherwise doing anything, but
this will change shortly.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The only reason the event ring's channel pointer is needed in
gsi_evt_ring_rx_update() is so we can get at its GSI pointer.
We can pass the GSI pointer as an argument, along with the event
ring ID, and thereby avoid using the event ring channel pointer.
This is another step toward no longer assuming an event ring
services a single channel.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In gsi_evt_ring_rx_update(), use gsi_event_trans() repeatedly
to find the transaction associated with an event, rather than
assuming consecutive events are associated with the same channel.
This removes the only caller of gsi_trans_pool_next(), so get rid
of it.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Rename gsi_channel_tx_update() to be gsi_trans_tx_completed(), and
pass it just the transaction pointer, deriving the channel from the
transaction. Update the comments above the function to provide a
more concise description of how statistics for TX endpoints are
maintained and used.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In gsi_evt_ring_rx_update(), we update each transaction so its len
field reflects the actual number of bytes received. In the process,
the total number of transactions and bytes processed on the channel
are summed, and added to a running total for the channel.
But we don't actually use those running totals for RX endpoints.
They're maintained for TX channels to support CoDel when they are
associated with a "real" network device.
So stop maintaining these totals for RX endpoints, and update the
comment where the fields are defined to make it clear they're only
valid for TX channels.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a TX request is issued, its channel's accumulated byte and
transaction counts are recorded. This currently does *not* take
into account the transaction being committed.
Later, when the transaction completes, the number of bytes and
transactions that have completed since the transaction was committed
are reported to the network stack. The transaction and its byte
count are accounted for at that time.
Instead, record the transaction and its bytes in the counts recorded
at commit time. This avoids the need to do so when the transaction
completes, and provides a (small) simplification of that code.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Create a new function that encapsulates recording information needed
for TX channel statistics when a transaction is committed.
Record the accumulated length in the transaction before the call
(for both RX and TX), so it can be used when updating TX statistics.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In gsi_channel_tx_queued(), we report when a transaction gets passed
to hardware. Change that function so it takes transaction rather
than a channel as its argument, and derive the channel from the
transaction. Rename the function accordingly.
Delete the header comments above the function definition; the ones
above the declaration in "gsi_private.h" should suffice. In
addition, the comments above gsi_channel_tx_update() do a fine job
of explaining what's going on.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Each event in an event ring describes the TRE whose completion
caused the event. Currently, every event ring is dedicated to a
single channel, so the channel is easily derived from the event
ring.
An event ring can actually be shared by more than one channel
though, and to distinguish events for one channel from another, the
event structure contains a field indicating which channel the event
is associated with.
In gsi_event_trans(), use the channel ID in an event to determine
which channel the event is for. This makes the channel pointer now
passed to that function irrelevant; pass the GSI pointer to that
function instead.
And although it shouldn't happen, warn if an event arrives that
records a channel ID that's not in use, or if the event does not
have a transaction associated with it.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Each GSI channel has a TLV FIFO of a certain size, specified in the
configuration data for an AP channel. That size dictates the
maximum number of TREs that are allowed in a single transaction.
The only way that value is used after initialization is as a limit
on the number of TREs in a transaction; calling it "tlv_count"
isn't helpful, and in fact gsi_channel_trans_tre_max() exists to
sort of abstract it.
Instead, rename the channel->tlv_count field trans_tre_max, and get
rid of the helper function. Update a couple of comments as well.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In commit 8797972aff ("net: ipa: remove command info pool"), the
maximum number of IPA commands that would be sent in a single
transaction was defined. That number can't exceed the size of the
TLV FIFO on the command channel, and we can check that at runtime.
To add this check, pass a new flag to gsi_channel_data_valid() to
indicate the channel being checked is being used for IPA commands.
Knowing that we can also verify the channel direction is correct.
Use a new local variable that refers to the command-specific portion
of the data being checked.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The CHANNEL_NOT_RUNNING error condition has been generalized, so
rename it to be INCORRECT_CHANNEL_STATE.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In gsi_channel_update(), a reference count is taken on the last
completed transaction "to keep it from completing" before we give
the event back to the hardware. Completion processing for that
transaction (and any other "new" ones) will not occur until after
this function returns, so there's no risk it completing early. So
there's no need to take and drop the additional transaction
reference.
Use local variables in the call to gsi_evt_ring_doorbell().
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Each time we are notified that some number of transactions on an RX
channel has completed, we record the number of bytes that have been
transferred since the previous notification. We also track the
number of transactions completed, but that is not currently being
calculated correctly; we're currently counting the number of such
notifications, but each notification can represent many transaction
completions. Fix this.
Fixes: 650d160382 ("soc: qcom: ipa: the generic software interface")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Switch net callers to the new API not requiring
the NAPI_POLL_WEIGHT argument.
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Acked-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Acked-by: Alexandra Winter <wintera@linux.ibm.com>
Link: https://lore.kernel.org/r/20220504163725.550782-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
IPA v4.2 introduced GSI channel flow control, used instead of IPA
endpoint DELAY mode to prevent a TX channel from injecting packets
into the IPA core. It used a new FLOW_CONTROLLED channel state
which could be entered using GSI generic commands.
IPA v4.11 extended the channel flow control model. Rather than
having a distinct FLOW_CONTROLLED channel state, each channel has a
"flow control" property that can be enabled or not--independent of
the channel state. The AP (or modem) can modify this property using
the same GSI generic commands as before.
The AP only uses channel flow control on modem TX channels, and only
when recovering from a modem crash. The AP has no way to discover
the state of a modem channel, so the fact that (starting with IPA
v4.11) flow control no longer uses a distinct channel state is
invisible to the AP. So enhanced flow control generally does not
change the way AP uses flow control.
There are a few small differences, however:
- There is a notion of "primary" or "secondary" flow control, and
when enabling or disabling flow control that must be specified
in a new field in the GSI generic command register. For now, we
always specify 0 (meaning "primary").
- When disabling flow control, it's possible a request will need
to be retried. We retry up to 5 times in this case.
- Another new generic command allows the current flow control
state to be queried. We do not use this.
Other than the need for retries, the code essentially works the same
way as before.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
One quirk for certain versions of IPA is that endpoint DELAY mode
does not work properly. IPA DELAY mode prevents any packets from
being delivered to the IPA core for processing on a TX endpoint.
The AP uses DELAY mode when the modem crashes, to prevent modem TX
endpoints from generating traffic during crash recovery. Without
this, there is a chance the hardware will stall during recovery from
a modem crash.
To achieve a similar effect, a GSI FLOW_CONTROLLED channel state
was created. A STARTED TX channel can be placed in FLOW_CONTROLLED
state, which prevents the transfer of any more packets. A channel
in FLOW_CONTROLLED state can be either returned to STARTED state, or
can be transitioned to STOPPED state.
Because this operates on GSI channels, two generic commands were
added to allow the AP to control this state for modem channels
(similar to the ALLOCATE and HALT channel commands).
Previously the code assumed this quirk only applied to IPA v4.2.
In fact, channel flow control (rather than endpoint DELAY mode)
should be used for all versions *starting* with IPA v4.2.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
