diff mbox series

[v2,1/3] mctp pcc: Check before sending MCTP PCC response ACK

Message ID 20240619200552.119080-2-admiyo@os.amperecomputing.com (mailing list archive)
State Changes Requested
Headers show
Series [v2,1/3] mctp pcc: Check before sending MCTP PCC response ACK | expand

Checks

Context Check Description
netdev/series_format warning Series does not have a cover letter
netdev/tree_selection success Guessed tree name to be net-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 845 this patch: 845
netdev/build_tools success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers warning 3 maintainers not CCed: linux-acpi@vger.kernel.org acpica-devel@lists.linux.dev rafael.j.wysocki@intel.com
netdev/build_clang success Errors and warnings before: 849 this patch: 849
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 856 this patch: 856
netdev/checkpatch warning CHECK: Unnecessary parentheses around 'pchan->type == ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE' WARNING: From:/Signed-off-by: email address mismatch: 'From: Adam Young <admiyo@amperecomputing.com>' != 'Signed-off-by: Adam Young <admiyo@os.amperecomputing.com>' WARNING: line length of 85 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

admiyo@os.amperecomputing.com June 19, 2024, 8:05 p.m. UTC 
From: Adam Young <admiyo@amperecomputing.com>

Type 4 PCC channels have an option to send back a response
to the platform when they are done processing the request.
The flag to indicate whether or not to respond is inside
the message body, and thus is not available to the pcc
mailbox.  Since only one message can be processed at once per
channel, the value of this flag is checked during message processing
and passed back via the channels global structure.

Ideally, the mailbox callback function would return a value
indicating whether the message requires an ACK, but that
would be a change to the mailbox API.  That would involve
some change to all (about 12) of the mailbox based drivers,
and the majority of them would not need to know about the
ACK call.

Signed-off-by: Adam Young <admiyo@os.amperecomputing.com>
---
 drivers/mailbox/pcc.c | 5 ++++-
 include/acpi/pcc.h    | 1 +
 2 files changed, 5 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
index 94885e411085..774727b89693 100644
--- a/drivers/mailbox/pcc.c
+++ b/drivers/mailbox/pcc.c
@@ -280,6 +280,7 @@  static irqreturn_t pcc_mbox_irq(int irq, void *p)
 {
 	struct pcc_chan_info *pchan;
 	struct mbox_chan *chan = p;
+	struct pcc_mbox_chan *pmchan;
 	u64 val;
 	int ret;
 
@@ -304,6 +305,8 @@  static irqreturn_t pcc_mbox_irq(int irq, void *p)
 	if (pcc_chan_reg_read_modify_write(&pchan->plat_irq_ack))
 		return IRQ_NONE;
 
+	pmchan = &pchan->chan;
+	pmchan->ack_rx = true;  //TODO default to False
 	mbox_chan_received_data(chan, NULL);
 
 	/*
@@ -312,7 +315,7 @@  static irqreturn_t pcc_mbox_irq(int irq, void *p)
 	 *
 	 * The PCC master subspace channel clears chan_in_use to free channel.
 	 */
-	if (pchan->type == ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE)
+	if ((pchan->type == ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE) && pmchan->ack_rx)
 		pcc_send_data(chan, NULL);
 	pchan->chan_in_use = false;
 
diff --git a/include/acpi/pcc.h b/include/acpi/pcc.h
index 9b373d172a77..297913378c2b 100644
--- a/include/acpi/pcc.h
+++ b/include/acpi/pcc.h
@@ -16,6 +16,7 @@  struct pcc_mbox_chan {
 	u32 latency;
 	u32 max_access_rate;
 	u16 min_turnaround_time;
+	bool ack_rx;
 };
 
 /* Generic Communications Channel Shared Memory Region */