msm: ipa3: fix race condition in SSR

On pipe setup, enable data path should happen for after
all pipe resources are allocated.
This change prevents a race condition where the pipe is enabled
before RX buffers are submitted to IPA.
Then, when buffers are submitted to IPA there is a race between
submitting the buffers and getting RX packets.

CRs-Fixed: 1096357
Change-Id: Ic32924b6893bb8c7813b1b8e68e03b5e09560b69
Acked-by: Ady Abraham <adya@qti.qualcomm.com>
Signed-off-by: Skylar Chang <chiaweic@codeaurora.org>

4 files changed, 33 insertions, 25 deletions

diff --git a/drivers/platform/msm/ipa/ipa_v3/ipa_client.c b/drivers/platform/msm/ipa/ipa_v3/ipa_client.c
index 00bfbf84c75a..e3dfe8927682 100644
--- a/drivers/platform/msm/ipa/ipa_v3/ipa_client.c
+++ b/drivers/platform/msm/ipa/ipa_v3/ipa_client.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2012-2016, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2012-2017, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -46,6 +46,20 @@ int ipa3_enable_data_path(u32 clnt_hdl)
 	int res = 0;
 	struct ipahal_reg_endp_init_rsrc_grp rsrc_grp;
 
+	/* Assign the resource group for pipe */
+	memset(&rsrc_grp, 0, sizeof(rsrc_grp));
+	rsrc_grp.rsrc_grp = ipa_get_ep_group(ep->client);
+	if (rsrc_grp.rsrc_grp == -1) {
+		IPAERR("invalid group for client %d\n", ep->client);
+		WARN_ON(1);
+		return -EFAULT;
+	}
+
+	IPADBG("Setting group %d for pipe %d\n",
+		rsrc_grp.rsrc_grp, clnt_hdl);
+	ipahal_write_reg_n_fields(IPA_ENDP_INIT_RSRC_GRP_n, clnt_hdl,
+		&rsrc_grp);
+
 	IPADBG("Enabling data path\n");
 	if (IPA_CLIENT_IS_CONS(ep->client)) {
 		memset(&holb_cfg, 0 , sizeof(holb_cfg));
@@ -64,20 +78,6 @@ int ipa3_enable_data_path(u32 clnt_hdl)
 		res = ipa3_cfg_ep_ctrl(clnt_hdl, &ep_cfg_ctrl);
 	}
 
-	/* Assign the resource group for pipe */
-	memset(&rsrc_grp, 0, sizeof(rsrc_grp));
-	rsrc_grp.rsrc_grp = ipa_get_ep_group(ep->client);
-	if (rsrc_grp.rsrc_grp == -1) {
-		IPAERR("invalid group for client %d\n", ep->client);
-		WARN_ON(1);
-		return -EFAULT;
-	}
-
-	IPADBG("Setting group %d for pipe %d\n",
-		rsrc_grp.rsrc_grp, clnt_hdl);
-	ipahal_write_reg_n_fields(IPA_ENDP_INIT_RSRC_GRP_n, clnt_hdl,
-		&rsrc_grp);
-
 	return res;
 }
 
diff --git a/drivers/platform/msm/ipa/ipa_v3/ipa_dp.c b/drivers/platform/msm/ipa/ipa_v3/ipa_dp.c
index be2946c873b3..c2c017ac172c 100644
--- a/drivers/platform/msm/ipa/ipa_v3/ipa_dp.c
+++ b/drivers/platform/msm/ipa/ipa_v3/ipa_dp.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2012-2016, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2012-2017, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -1360,13 +1360,6 @@ int ipa3_setup_sys_pipe(struct ipa_sys_connect_params *sys_in, u32 *clnt_hdl)
 		}
 	}
 
-	result = ipa3_enable_data_path(ipa_ep_idx);
-	if (result) {
-		IPAERR("enable data path failed res=%d clnt=%d.\n", result,
-				ipa_ep_idx);
-		goto fail_gen2;
-	}
-
 	if (!ep->skip_ep_cfg) {
 		if (ipa3_cfg_ep(ipa_ep_idx, &sys_in->ipa_ep_cfg)) {
 			IPAERR("fail to configure EP.\n");
@@ -1498,6 +1491,13 @@ int ipa3_setup_sys_pipe(struct ipa_sys_connect_params *sys_in, u32 *clnt_hdl)
 			ipa3_install_dflt_flt_rules(ipa_ep_idx);
 	}
 
+	result = ipa3_enable_data_path(ipa_ep_idx);
+	if (result) {
+		IPAERR("enable data path failed res=%d ep=%d.\n", result,
+			ipa_ep_idx);
+		goto fail_gen2;
+	}
+
 	if (!ep->keep_ipa_awake)
 		IPA_ACTIVE_CLIENTS_DEC_EP(sys_in->client);
 
diff --git a/drivers/platform/msm/ipa/ipa_v3/ipa_i.h b/drivers/platform/msm/ipa/ipa_v3/ipa_i.h
index 7feb1c1ce178..ec26eea1e033 100644
--- a/drivers/platform/msm/ipa/ipa_v3/ipa_i.h
+++ b/drivers/platform/msm/ipa/ipa_v3/ipa_i.h
@@ -42,6 +42,7 @@
 #define IPA_COOKIE 0x57831603
 #define MTU_BYTE 1500
 
+#define IPA_EP_NOT_ALLOCATED (-1)
 #define IPA3_MAX_NUM_PIPES 31
 #define IPA_SYS_DESC_FIFO_SZ 0x800
 #define IPA_SYS_TX_DATA_DESC_FIFO_SZ 0x1000
diff --git a/drivers/platform/msm/ipa/ipa_v3/ipa_utils.c b/drivers/platform/msm/ipa/ipa_v3/ipa_utils.c
index 3b909acdd823..944c40eb03d8 100644
--- a/drivers/platform/msm/ipa/ipa_v3/ipa_utils.c
+++ b/drivers/platform/msm/ipa/ipa_v3/ipa_utils.c
@@ -95,7 +95,8 @@
 #define QMB_MASTER_SELECT_PCIE (1)
 
 #define IPA_CLIENT_NOT_USED \
-	{-1, -1, false, IPA_DPS_HPS_SEQ_TYPE_INVALID, QMB_MASTER_SELECT_DDR}
+	{IPA_EP_NOT_ALLOCATED, IPA_EP_NOT_ALLOCATED, false, \
+		IPA_DPS_HPS_SEQ_TYPE_INVALID, QMB_MASTER_SELECT_DDR}
 
 /* Resource Group index*/
 #define IPA_GROUP_UL		(0)
@@ -919,12 +920,18 @@ u8 ipa3_get_hw_type_index(void)
  */
 int ipa3_get_ep_mapping(enum ipa_client_type client)
 {
+	int ipa_ep_idx;
+
 	if (client >= IPA_CLIENT_MAX || client < 0) {
 		IPAERR("Bad client number! client =%d\n", client);
 		return -EINVAL;
 	}
 
-	return ipa3_ep_mapping[ipa3_get_hw_type_index()][client].pipe_num;
+	ipa_ep_idx = ipa3_ep_mapping[ipa3_get_hw_type_index()][client].pipe_num;
+	if (ipa_ep_idx < 0 || ipa_ep_idx >= IPA3_MAX_NUM_PIPES)
+		return IPA_EP_NOT_ALLOCATED;
+
+	return ipa_ep_idx;
 }
 
 /**