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12 commits

Author SHA1 Message Date
Wang Wenhu 8fa54b1160 drivers: ipa: fix typoes for ipa
Change "transactio" -> "transaction". Also an alignment correction.

Signed-off-by: Wang Wenhu <wenhu.wang@vivo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-27 14:58:28 -07:00
David S. Miller 13209a8f73 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
The MSCC bug fix in 'net' had to be slightly adjusted because the
register accesses are done slightly differently in net-next.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-24 13:47:27 -07:00
Alex Elder 195ef57f87 net: ipa: do not clear interrupt in gsi_channel_start()
In gsi_channel_start() there is harmless-looking comment "Clear the
channel's event ring interrupt in case it's pending".  The intent
was to avoid getting spurious interrupts when first bringing up a
channel.

However we now use channel stop/start to implement suspend and
resume, and an interrupt pending at the time we resume is actually
something we don't want to ignore.

The very first time we bring up the channel we do not expect an
interrupt to be pending, and even if it were, the effect would
simply be to schedule NAPI on that channel, which would find nothing
to do, which is not a problem.

Stop clearing any pending IEOB interrupt in gsi_channel_start().
That leaves one caller of the trivial function gsi_isr_ieob_clear().
Get rid of that function and just open-code it in gsi_isr_ieob()
instead.

This fixes a problem where suspend/resume IPA v4.2 would get stuck
when resuming after a suspend.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-16 16:47:19 -07:00
Alex Elder f45a7bccdc net: ipa: don't be a hog in gsi_channel_poll()
The iteration count value used in gsi_channel_poll() is intended to
limit poll iterations to the budget supplied as an argument.  But
it's never updated.

Fix this bug by incrementing the count each time through the loop.

Reported-by: Sharath Chandra Vurukala <sharathv@codeaurora.com>
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-16 15:14:54 -07:00
David S. Miller 3793faad7b Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts were all overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-06 22:10:13 -07:00
Alex Elder a3f2405b04 net: ipa: only reset channel twice for IPA v3.5.1
In gsi_channel_reset(), RX channels are subjected to two consecutive
CHANNEL_RESET commands.  This workaround should only be used for IPA
version 3.5.1, and for newer hardware "can lead to unwanted behavior."

Only issue the second CHANNEL_RESET command for legacy hardware.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-06 17:36:04 -07:00
Alex Elder f86a1909ea net: ipa: rename db_enable flag
In several places, a Boolean flag is used in the GSI code to
indicate whether the "doorbell engine" should be enabled or not
when a channel is configured.  This is basically done to abstract
this property from the IPA version; the GSI code doesn't otherwise
"know" what the IPA hardware version is.  The doorbell engine is
enabled only for IPA v3.5.1, not for IPA v4.0 and later.

The next patch makes another change that affects behavior during
channel reset (which also involves programming the channel).  It
also distinguishes IPA v3.5.1 hardware from newer hardware.

Rather than creating another flag whose value matches the "db_enable"
value, just rename "db_enable" to be "legacy" so it can be used to
signal more than just the special doorbell handling.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-06 17:36:04 -07:00
Alex Elder a2003b3038 net: ipa: do not cache channel state
It is possible for a GSI channel's state to be changed as a result
of an action by a different execution environment.  Specifically,
the modem is able to issue a GSI generic command that causes a state
change on a GSI channel associated with the AP.

A channel's state only needs to be known when a channel is allocated
or deallocaed, started or stopped, or reset.  So there is little
value in caching the state anyway.

Stop recording a copy of the channel's last known state, and instead
fetch the true state from hardware whenever it's needed.  In such
cases, *do* record the state in a local variable, in case an error
message reports it (so the value reported is the value seen).

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01 15:53:33 -07:00
Alex Elder aba7924fa5 net: ipa: pass channel pointer to gsi_channel_state()
Pass a channel pointer rather than a GSI pointer and channel ID to
gsi_channel_state().

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01 15:53:33 -07:00
Alex Elder 0b1ba18aec net: ipa: zero return code before issuing generic EE command
Zero the result code stored in a field of the scratch 0 register
before issuing a generic EE command.  This just guarantees that
the value we read later was actually written as a result of the
command.

Also add the definitions of two more possible result codes that can
be returned when issuing flow control enable or disable commands:
  INCORRECT_CHANNEL_STATE: - channel must be in started state
  INCORRECT_DIRECTION - flow control is only valid for TX channels

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 18:04:58 -07:00
Alex Elder 0721999f15 net: ipa: fix an error message in gsi_channel_init_one()
An error message about limiting the number of TREs used prints the
wrong value.  Fix this bug.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 18:04:58 -07:00
Alex Elder 650d160382 soc: qcom: ipa: the generic software interface
This patch includes "gsi.c", which implements the generic software
interface (GSI) for IPA.  The generic software interface abstracts
channels, which provide a means of transferring data either from the
AP to the IPA, or from the IPA to the AP.  A ring buffer of "transfer
elements" (TREs) is used to describe data transfers to perform.  The
AP writes a doorbell register associated with a channel to let it know
it has added new entries (for an AP->IPA channel) or has finished
processing entries (for an IPA->AP channel).

Each channel also has an event ring buffer, used by the IPA to
communicate information about events related to a channel (for
example, the completion of TREs).  The IPA writes its own doorbell
register, which triggers an interrupt on the AP, to signal that
new event information has arrived.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-08 22:07:09 -07:00