Re: [RFC PATCH 13/17] net: ipa: Add support for IPA v2.x in the driver's QMI interface

On Thu Oct 14, 2021 at 4:00 AM IST, Alex Elder wrote:

On 9/19/21 10:08 PM, Sireesh Kodali wrote:

quoted

On IPA v2.x, the modem doesn't send a DRIVER_INIT_COMPLETED, so we have
to rely on the uc's IPA_UC_RESPONSE_INIT_COMPLETED to know when its
ready. We add a function here that marks uc_ready = true. This function
is called by ipa_uc.c when IPA_UC_RESPONSE_INIT_COMPLETED is handled.

This should use the new ipa_mem_find() interface for getting the
memory information for the ZIP region.

Got it, thanks

I don't know where the IPA_UC_RESPONSE_INIT_COMPLETED gets sent
but I presume it ends up calling ipa_qmi_signal_uc_loaded().

IPA_UC_RESPONSE_INIT_COMPLETED is handled by the ipa_uc sub-driver. The
handler calls ipa_qmi_signal_uc_loaded() once the response is received,
at which point we know the uc has been inited.

I think actually the DRIVER_INIT_COMPLETE message from the modem
is saying "I finished initializing the microcontroller." And
I've wondered why there is a duplicate mechanism. Maybe there
was a race or something.

This makes sense. Given that some modems rely on the IPA block for
initialization, I wonder if Qualcomm decided it would be easier to allow
the modem to complete the uc initialization and send the signal instead.

Regards,
Sireesh

-Alex

quoted

Signed-off-by: Sireesh Kodali <redacted>
Signed-off-by: Vladimir Lypak <redacted>
---
  drivers/net/ipa/ipa_qmi.c | 27 ++++++++++++++++++++++++++-
  drivers/net/ipa/ipa_qmi.h | 10 ++++++++++
  2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ipa/ipa_qmi.c b/drivers/net/ipa/ipa_qmi.c
index 7e2fe701cc4d..876e2a004f70 100644
--- a/drivers/net/ipa/ipa_qmi.c
+++ b/drivers/net/ipa/ipa_qmi.c

@@ -68,6 +68,11 @@
   * - The INDICATION_REGISTER request and INIT_COMPLETE indication are
   *   optional for non-initial modem boots, and have no bearing on the
   *   determination of when things are "ready"
+ *
+ * Note that on IPA v2.x, the modem doesn't send a DRIVER_INIT_COMPLETE
+ * request. Thus, we rely on the uc's IPA_UC_RESPONSE_INIT_COMPLETED to know
+ * when the uc is ready. The rest of the process is the same on IPA v2.x and
+ * later IPA versions
   */
  
  #define IPA_HOST_SERVICE_SVC_ID		0x31

@@ -345,7 +350,12 @@ init_modem_driver_req(struct ipa_qmi *ipa_qmi)
  			req.hdr_proc_ctx_tbl_info.start + mem->size - 1;
  	}
  
-	/* Nothing to report for the compression table (zip_tbl_info) */
+	mem = &ipa->mem[IPA_MEM_ZIP];
+	if (mem->size) {
+		req.zip_tbl_info_valid = 1;
+		req.zip_tbl_info.start = ipa->mem_offset + mem->offset;
+		req.zip_tbl_info.end = ipa->mem_offset + mem->size - 1;
+	}
  
  	mem = ipa_mem_find(ipa, IPA_MEM_V4_ROUTE_HASHED);
  	if (mem->size) {

@@ -525,6 +535,21 @@ int ipa_qmi_setup(struct ipa *ipa)
  	return ret;
  }
  
+/* With IPA v2 modem is not required to send DRIVER_INIT_COMPLETE request to AP.
+ * We start operation as soon as IPA_UC_RESPONSE_INIT_COMPLETED irq is triggered.
+ */
+void ipa_qmi_signal_uc_loaded(struct ipa *ipa)
+{
+	struct ipa_qmi *ipa_qmi = &ipa->qmi;
+
+	/* This is needed only on IPA 2.x */
+	if (ipa->version > IPA_VERSION_2_6L)
+		return;
+
+	ipa_qmi->uc_ready = true;
+	ipa_qmi_ready(ipa_qmi);
+}
+
  /* Tear down IPA QMI handles */
  void ipa_qmi_teardown(struct ipa *ipa)
  {

diff --git a/drivers/net/ipa/ipa_qmi.h b/drivers/net/ipa/ipa_qmi.h
index 856ef629ccc8..4962d88b0d22 100644
--- a/drivers/net/ipa/ipa_qmi.h
+++ b/drivers/net/ipa/ipa_qmi.h

@@ -55,6 +55,16 @@ struct ipa_qmi {
   */
  int ipa_qmi_setup(struct ipa *ipa);
  
+/**
+ * ipa_qmi_signal_uc_loaded() - Signal that the UC has been loaded
+ * @ipa:		IPA pointer
+ *
+ * This is called when the uc indicates that it is ready. This exists, because
+ * on IPA v2.x, the modem does not send a DRIVER_INIT_COMPLETED. Thus we have
+ * to rely on the uc's INIT_COMPLETED response to know if it was initialized
+ */
+void ipa_qmi_signal_uc_loaded(struct ipa *ipa);
+
  /**
   * ipa_qmi_teardown() - Tear down IPA QMI handles
   * @ipa:		IPA pointer