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* [net-next PATCH 0/5] Add support for netcp driver on K2G SoC
@ 2018-03-26 20:15 Murali Karicheri
  2018-03-26 20:15 ` [net-next PATCH 1/5] soc: ti: K2G: enhancement to support QMSS in NSS Murali Karicheri
                   ` (4 more replies)
  0 siblings, 5 replies; 13+ messages in thread
From: Murali Karicheri @ 2018-03-26 20:15 UTC (permalink / raw)
  To: robh+dt, mark.rutland, ssantosh, malat, w-kwok2, devicetree,
	linux-kernel, linux-arm-kernel, davem, netdev

K2G SoC is another variant of Keystone family of SoCs. This patch
series add support for NetCP driver on this SoC. The QMSS found on
K2G SoC is a cut down version of the QMSS found on other keystone
devices with less number of queues, internal link ram etc. The patch
series has 2 patch sets that goes into the drivers/soc and the
rest has to be applied to net sub system. Please review and merge
if this looks good.

Thanks

The boot logs on K2G ICE board (tftp boot over Ethernet)
is at https://pastebin.ubuntu.com/p/VQTv3c2XBS/

The boot logs on K2G GP board (tftp boot over Ethernet)
is at https://pastebin.ubuntu.com/p/6Vh55DW8vT/

This series applies to net-next master branch.

Murali Karicheri (5):
  soc: ti: K2G: enhancement to support QMSS in NSS
  soc: ti: K2G: provide APIs to support driver probe deferral
  net: netcp: ethss enhancements to support 2u cpsw h/w on K2G SoC
  Revert "net: netcp: remove dead code from the driver"
  net: netcp: support probe deferral

 .../bindings/soc/ti/keystone-navigator-qmss.txt    |  7 ++
 drivers/net/ethernet/ti/netcp.h                    |  3 +
 drivers/net/ethernet/ti/netcp_core.c               | 13 +++
 drivers/net/ethernet/ti/netcp_ethss.c              | 75 ++++++++++++++---
 drivers/soc/ti/knav_dma.c                          |  8 ++
 drivers/soc/ti/knav_qmss.h                         |  6 ++
 drivers/soc/ti/knav_qmss_queue.c                   | 98 +++++++++++++++++-----
 include/linux/soc/ti/knav_dma.h                    | 12 +++
 include/linux/soc/ti/knav_qmss.h                   |  1 +
 9 files changed, 190 insertions(+), 33 deletions(-)

-- 
1.9.1

^ permalink raw reply	[flat|nested] 13+ messages in thread

* [net-next PATCH 1/5] soc: ti: K2G: enhancement to support QMSS in NSS
  2018-03-26 20:15 [net-next PATCH 0/5] Add support for netcp driver on K2G SoC Murali Karicheri
@ 2018-03-26 20:15 ` Murali Karicheri
  2018-03-26 20:15 ` [net-next PATCH 2/5] soc: ti: K2G: provide APIs to support driver probe deferral Murali Karicheri
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 13+ messages in thread
From: Murali Karicheri @ 2018-03-26 20:15 UTC (permalink / raw)
  To: robh+dt, mark.rutland, ssantosh, malat, w-kwok2, devicetree,
	linux-kernel, linux-arm-kernel, davem, netdev

Navigator Subsystem (NSS) available on K2G SoC has a cut down
version of QMSS with less number of queues, internal linking ram
with lesser number of buffers etc.  It doesn't have status and
explicit push register space as in QMSS available on other K2 SoCs.
So define reg indices specific to QMSS on K2G. This patch introduces
"keystone-navigator-qmss-l" compatibility to identify QMSS on
K2G NSS (QMSS Lite) and to customize the dts handling code. Per
Device manual, descriptors with index less than or equal to
regions0_size is in region 0 in the case of QMSS where as for
QMSS Lite, descriptors with index less than regions0_size is in
region 0. So update the size accordingly in the regions0_size bits
of the linking ram size 0 register.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: WingMan Kwok <w-kwok2@ti.com>
---
 .../bindings/soc/ti/keystone-navigator-qmss.txt    |  7 ++
 drivers/soc/ti/knav_qmss.h                         |  6 ++
 drivers/soc/ti/knav_qmss_queue.c                   | 90 ++++++++++++++++------
 3 files changed, 81 insertions(+), 22 deletions(-)

diff --git a/Documentation/devicetree/bindings/soc/ti/keystone-navigator-qmss.txt b/Documentation/devicetree/bindings/soc/ti/keystone-navigator-qmss.txt
index 77cd42c..1b0878a 100644
--- a/Documentation/devicetree/bindings/soc/ti/keystone-navigator-qmss.txt
+++ b/Documentation/devicetree/bindings/soc/ti/keystone-navigator-qmss.txt
@@ -18,6 +18,7 @@ pool management.
 
 Required properties:
 - compatible	: Must be "ti,keystone-navigator-qmss";
+		: Must be "ti,keystone-navigator-qmss-l" for NSS Lite
 - clocks	: phandle to the reference clock for this device.
 - queue-range	: <start number> total range of queue numbers for the device.
 - linkram0	: <address size> for internal link ram, where size is the total
@@ -39,6 +40,12 @@ Required properties:
 			  - Descriptor memory setup region.
 			  - Queue Management/Queue Proxy region for queue Push.
 			  - Queue Management/Queue Proxy region for queue Pop.
+
+For NSS lite, following QMSS reg indexes are used in that order
+			  - Queue Peek region.
+			  - Queue configuration region.
+			  - Queue Management/Queue Proxy region for queue Push/Pop.
+
 - queue-pools	: child node classifying the queue ranges into pools.
 		  Queue ranges are grouped into 3 type of pools:
 		  - qpend	    : pool of qpend(interruptible) queues
diff --git a/drivers/soc/ti/knav_qmss.h b/drivers/soc/ti/knav_qmss.h
index 905b974..5fa1ce6 100644
--- a/drivers/soc/ti/knav_qmss.h
+++ b/drivers/soc/ti/knav_qmss.h
@@ -292,6 +292,11 @@ struct knav_queue {
 	struct list_head		list;
 };
 
+enum qmss_version {
+	QMSS,
+	QMSS_LITE,
+};
+
 struct knav_device {
 	struct device				*dev;
 	unsigned				base_id;
@@ -305,6 +310,7 @@ struct knav_device {
 	struct list_head			pools;
 	struct list_head			pdsps;
 	struct list_head			qmgrs;
+	enum qmss_version			version;
 };
 
 struct knav_range_ops {
diff --git a/drivers/soc/ti/knav_qmss_queue.c b/drivers/soc/ti/knav_qmss_queue.c
index 77d6b5c..5b2c4e9 100644
--- a/drivers/soc/ti/knav_qmss_queue.c
+++ b/drivers/soc/ti/knav_qmss_queue.c
@@ -42,6 +42,15 @@
 #define KNAV_QUEUE_PUSH_REG_INDEX	4
 #define KNAV_QUEUE_POP_REG_INDEX	5
 
+/* Queue manager register indices in DTS for QMSS in NSS lite.
+ * There are no status and vbusm push registers on this version
+ * QMSS. Push registers are same as pop, So all indices above 1
+ * are to be re-defined
+ */
+#define KNAV_L_QUEUE_CONFIG_REG_INDEX	1
+#define KNAV_L_QUEUE_REGION_REG_INDEX	2
+#define KNAV_L_QUEUE_PUSH_REG_INDEX	3
+
 /* PDSP register indices in DTS */
 #define KNAV_QUEUE_PDSP_IRAM_REG_INDEX	0
 #define KNAV_QUEUE_PDSP_REGS_REG_INDEX	1
@@ -1169,8 +1178,12 @@ static int knav_queue_setup_link_ram(struct knav_device *kdev)
 		dev_dbg(kdev->dev, "linkram0: dma:%pad, virt:%p, size:%x\n",
 			&block->dma, block->virt, block->size);
 		writel_relaxed((u32)block->dma, &qmgr->reg_config->link_ram_base0);
-		writel_relaxed(block->size, &qmgr->reg_config->link_ram_size0);
-
+		if (kdev->version == QMSS_LITE)
+			writel_relaxed(block->size,
+				       &qmgr->reg_config->link_ram_size0);
+		else
+			writel_relaxed(block->size - 1,
+				       &qmgr->reg_config->link_ram_size0);
 		block++;
 		if (!block->size)
 			continue;
@@ -1387,42 +1400,64 @@ static int knav_queue_init_qmgrs(struct knav_device *kdev,
 		qmgr->reg_peek =
 			knav_queue_map_reg(kdev, child,
 					   KNAV_QUEUE_PEEK_REG_INDEX);
-		qmgr->reg_status =
-			knav_queue_map_reg(kdev, child,
-					   KNAV_QUEUE_STATUS_REG_INDEX);
+
+		if (kdev->version == QMSS) {
+			qmgr->reg_status =
+				knav_queue_map_reg(kdev, child,
+						   KNAV_QUEUE_STATUS_REG_INDEX);
+		}
+
 		qmgr->reg_config =
 			knav_queue_map_reg(kdev, child,
+					   (kdev->version == QMSS_LITE) ?
+					   KNAV_L_QUEUE_CONFIG_REG_INDEX :
 					   KNAV_QUEUE_CONFIG_REG_INDEX);
 		qmgr->reg_region =
 			knav_queue_map_reg(kdev, child,
+					   (kdev->version == QMSS_LITE) ?
+					   KNAV_L_QUEUE_REGION_REG_INDEX :
 					   KNAV_QUEUE_REGION_REG_INDEX);
+
 		qmgr->reg_push =
 			knav_queue_map_reg(kdev, child,
-					   KNAV_QUEUE_PUSH_REG_INDEX);
-		qmgr->reg_pop =
-			knav_queue_map_reg(kdev, child,
-					   KNAV_QUEUE_POP_REG_INDEX);
+					   (kdev->version == QMSS_LITE) ?
+					    KNAV_L_QUEUE_PUSH_REG_INDEX :
+					    KNAV_QUEUE_PUSH_REG_INDEX);
+
+		if (kdev->version == QMSS) {
+			qmgr->reg_pop =
+				knav_queue_map_reg(kdev, child,
+						   KNAV_QUEUE_POP_REG_INDEX);
+		}
 
-		if (IS_ERR(qmgr->reg_peek) || IS_ERR(qmgr->reg_status) ||
+		if (IS_ERR(qmgr->reg_peek) ||
+		    ((kdev->version == QMSS) &&
+		    (IS_ERR(qmgr->reg_status) || IS_ERR(qmgr->reg_pop))) ||
 		    IS_ERR(qmgr->reg_config) || IS_ERR(qmgr->reg_region) ||
-		    IS_ERR(qmgr->reg_push) || IS_ERR(qmgr->reg_pop)) {
+		    IS_ERR(qmgr->reg_push)) {
 			dev_err(dev, "failed to map qmgr regs\n");
+			if (kdev->version == QMSS) {
+				if (!IS_ERR(qmgr->reg_status))
+					devm_iounmap(dev, qmgr->reg_status);
+				if (!IS_ERR(qmgr->reg_pop))
+					devm_iounmap(dev, qmgr->reg_pop);
+			}
 			if (!IS_ERR(qmgr->reg_peek))
 				devm_iounmap(dev, qmgr->reg_peek);
-			if (!IS_ERR(qmgr->reg_status))
-				devm_iounmap(dev, qmgr->reg_status);
 			if (!IS_ERR(qmgr->reg_config))
 				devm_iounmap(dev, qmgr->reg_config);
 			if (!IS_ERR(qmgr->reg_region))
 				devm_iounmap(dev, qmgr->reg_region);
 			if (!IS_ERR(qmgr->reg_push))
 				devm_iounmap(dev, qmgr->reg_push);
-			if (!IS_ERR(qmgr->reg_pop))
-				devm_iounmap(dev, qmgr->reg_pop);
 			devm_kfree(dev, qmgr);
 			continue;
 		}
 
+		/* Use same push register for pop as well */
+		if (kdev->version == QMSS_LITE)
+			qmgr->reg_pop = qmgr->reg_push;
+
 		list_add_tail(&qmgr->list, &kdev->qmgrs);
 		dev_info(dev, "added qmgr start queue %d, num of queues %d, reg_peek %p, reg_status %p, reg_config %p, reg_region %p, reg_push %p, reg_pop %p\n",
 			 qmgr->start_queue, qmgr->num_queues,
@@ -1681,10 +1716,24 @@ static int knav_queue_init_queues(struct knav_device *kdev)
 	return 0;
 }
 
+/* Match table for of_platform binding */
+static const struct of_device_id keystone_qmss_of_match[] = {
+	{
+		.compatible = "ti,keystone-navigator-qmss",
+	},
+	{
+		.compatible = "ti,keystone-navigator-qmss-l",
+		.data	= (void *)QMSS_LITE,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, keystone_qmss_of_match);
+
 static int knav_queue_probe(struct platform_device *pdev)
 {
 	struct device_node *node = pdev->dev.of_node;
 	struct device_node *qmgrs, *queue_pools, *regions, *pdsps;
+	const struct of_device_id *match;
 	struct device *dev = &pdev->dev;
 	u32 temp[2];
 	int ret;
@@ -1700,6 +1749,10 @@ static int knav_queue_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
+	match = of_match_device(of_match_ptr(keystone_qmss_of_match), dev);
+	if (match && match->data)
+		kdev->version = QMSS_LITE;
+
 	platform_set_drvdata(pdev, kdev);
 	kdev->dev = dev;
 	INIT_LIST_HEAD(&kdev->queue_ranges);
@@ -1815,13 +1868,6 @@ static int knav_queue_remove(struct platform_device *pdev)
 	return 0;
 }
 
-/* Match table for of_platform binding */
-static struct of_device_id keystone_qmss_of_match[] = {
-	{ .compatible = "ti,keystone-navigator-qmss", },
-	{},
-};
-MODULE_DEVICE_TABLE(of, keystone_qmss_of_match);
-
 static struct platform_driver keystone_qmss_driver = {
 	.probe		= knav_queue_probe,
 	.remove		= knav_queue_remove,
-- 
1.9.1

^ permalink raw reply related	[flat|nested] 13+ messages in thread

* [net-next PATCH 2/5] soc: ti: K2G: provide APIs to support driver probe deferral
  2018-03-26 20:15 [net-next PATCH 0/5] Add support for netcp driver on K2G SoC Murali Karicheri
  2018-03-26 20:15 ` [net-next PATCH 1/5] soc: ti: K2G: enhancement to support QMSS in NSS Murali Karicheri
@ 2018-03-26 20:15 ` Murali Karicheri
  2018-03-26 20:48   ` Andrew Lunn
  2018-03-26 20:15 ` [net-next PATCH 3/5] net: netcp: ethss enhancements to support 2u cpsw h/w on K2G SoC Murali Karicheri
                   ` (2 subsequent siblings)
  4 siblings, 1 reply; 13+ messages in thread
From: Murali Karicheri @ 2018-03-26 20:15 UTC (permalink / raw)
  To: robh+dt, mark.rutland, ssantosh, malat, w-kwok2, devicetree,
	linux-kernel, linux-arm-kernel, davem, netdev

This patch provide APIs to allow client drivers to support
probe deferral. On K2G SoC, devices can be probed only
after the ti_sci_pm_domains driver is probed and ready.
As drivers may get probed at different order, any driver
that depends on knav dma and qmss drivers, for example
netcp network driver, needs to defer probe until
knav devices are probed and ready to service. To do this,
add an API to query the device ready status from the knav
dma and qmss devices.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
---
 drivers/soc/ti/knav_dma.c        |  8 ++++++++
 drivers/soc/ti/knav_qmss_queue.c |  8 ++++++++
 include/linux/soc/ti/knav_dma.h  | 12 ++++++++++++
 include/linux/soc/ti/knav_qmss.h |  1 +
 4 files changed, 29 insertions(+)

diff --git a/drivers/soc/ti/knav_dma.c b/drivers/soc/ti/knav_dma.c
index 026182d..224d7dd 100644
--- a/drivers/soc/ti/knav_dma.c
+++ b/drivers/soc/ti/knav_dma.c
@@ -134,6 +134,13 @@ struct knav_dma_chan {
 
 static struct knav_dma_pool_device *kdev;
 
+static bool device_ready;
+bool knav_dma_device_ready(void)
+{
+	return device_ready;
+}
+EXPORT_SYMBOL_GPL(knav_dma_device_ready);
+
 static bool check_config(struct knav_dma_chan *chan, struct knav_dma_cfg *cfg)
 {
 	if (!memcmp(&chan->cfg, cfg, sizeof(*cfg)))
@@ -773,6 +780,7 @@ static int knav_dma_probe(struct platform_device *pdev)
 	debugfs_create_file("knav_dma", S_IFREG | S_IRUGO, NULL, NULL,
 			    &knav_dma_debug_ops);
 
+	device_ready = true;
 	return ret;
 }
 
diff --git a/drivers/soc/ti/knav_qmss_queue.c b/drivers/soc/ti/knav_qmss_queue.c
index 5b2c4e9..f0e67aa 100644
--- a/drivers/soc/ti/knav_qmss_queue.c
+++ b/drivers/soc/ti/knav_qmss_queue.c
@@ -74,6 +74,13 @@
  */
 const char *knav_acc_firmwares[] = {"ks2_qmss_pdsp_acc48.bin"};
 
+static bool device_ready;
+bool knav_qmss_device_ready(void)
+{
+	return device_ready;
+}
+EXPORT_SYMBOL_GPL(knav_qmss_device_ready);
+
 /**
  * knav_queue_notify: qmss queue notfier call
  *
@@ -1849,6 +1856,7 @@ static int knav_queue_probe(struct platform_device *pdev)
 
 	debugfs_create_file("qmss", S_IFREG | S_IRUGO, NULL, NULL,
 			    &knav_queue_debug_ops);
+	device_ready = true;
 	return 0;
 
 err:
diff --git a/include/linux/soc/ti/knav_dma.h b/include/linux/soc/ti/knav_dma.h
index 66693bc..7127ec3 100644
--- a/include/linux/soc/ti/knav_dma.h
+++ b/include/linux/soc/ti/knav_dma.h
@@ -167,6 +167,8 @@ struct knav_dma_desc {
 void *knav_dma_open_channel(struct device *dev, const char *name,
 				struct knav_dma_cfg *config);
 void knav_dma_close_channel(void *channel);
+int knav_dma_get_flow(void *channel);
+bool knav_dma_device_ready(void);
 #else
 static inline void *knav_dma_open_channel(struct device *dev, const char *name,
 				struct knav_dma_cfg *config)
@@ -176,6 +178,16 @@ static inline void *knav_dma_open_channel(struct device *dev, const char *name,
 static inline void knav_dma_close_channel(void *channel)
 {}
 
+static inline int knav_dma_get_flow(void *channel)
+{
+	return -EINVAL;
+}
+
+static inline bool knav_dma_device_ready(void)
+{
+	return false;
+}
+
 #endif
 
 #endif /* __SOC_TI_KEYSTONE_NAVIGATOR_DMA_H__ */
diff --git a/include/linux/soc/ti/knav_qmss.h b/include/linux/soc/ti/knav_qmss.h
index 9f0ebb3b..9745df6 100644
--- a/include/linux/soc/ti/knav_qmss.h
+++ b/include/linux/soc/ti/knav_qmss.h
@@ -86,5 +86,6 @@ int knav_pool_desc_map(void *ph, void *desc, unsigned size,
 void *knav_pool_desc_unmap(void *ph, dma_addr_t dma, unsigned dma_sz);
 dma_addr_t knav_pool_desc_virt_to_dma(void *ph, void *virt);
 void *knav_pool_desc_dma_to_virt(void *ph, dma_addr_t dma);
+bool knav_qmss_device_ready(void);
 
 #endif /* __SOC_TI_KNAV_QMSS_H__ */
-- 
1.9.1

^ permalink raw reply related	[flat|nested] 13+ messages in thread

* [net-next PATCH 3/5] net: netcp: ethss enhancements to support 2u cpsw h/w on K2G SoC
  2018-03-26 20:15 [net-next PATCH 0/5] Add support for netcp driver on K2G SoC Murali Karicheri
  2018-03-26 20:15 ` [net-next PATCH 1/5] soc: ti: K2G: enhancement to support QMSS in NSS Murali Karicheri
  2018-03-26 20:15 ` [net-next PATCH 2/5] soc: ti: K2G: provide APIs to support driver probe deferral Murali Karicheri
@ 2018-03-26 20:15 ` Murali Karicheri
  2018-03-26 20:28   ` Andrew Lunn
  2018-03-26 20:15 ` [net-next PATCH 4/5] Revert "net: netcp: remove dead code from the driver" Murali Karicheri
  2018-03-26 20:15 ` [net-next PATCH 5/5] net: netcp: support probe deferral Murali Karicheri
  4 siblings, 1 reply; 13+ messages in thread
From: Murali Karicheri @ 2018-03-26 20:15 UTC (permalink / raw)
  To: robh+dt, mark.rutland, ssantosh, malat, w-kwok2, devicetree,
	linux-kernel, linux-arm-kernel, davem, netdev

K2G SoC uses 2u cpsw h/w. It uses RGMII instead of SGMII to interface with
Phy. This patch enhances the driver to check RGMII status instead of SGMII
status for link state determination. Also map all of the vlan priorities
to zero as the packet DMA is enabled to receive only flow id 0 which maps
to priority zero.

Additionally, When a phy with rgmii interface requires internal delay, the
same is set in the phy driver. To support such phy devices, add a phy-mode
handling code in the driver using of_get_phy_mode() and pass the obtained
phy mode to of_phy_connect()

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Wingman Kwok <w-kwok2@ti.com>
---
 drivers/net/ethernet/ti/netcp.h       |  3 ++
 drivers/net/ethernet/ti/netcp_ethss.c | 75 ++++++++++++++++++++++++++++++-----
 2 files changed, 67 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/ti/netcp.h b/drivers/net/ethernet/ti/netcp.h
index 8900a6f..3e3193c 100644
--- a/drivers/net/ethernet/ti/netcp.h
+++ b/drivers/net/ethernet/ti/netcp.h
@@ -33,6 +33,9 @@
 #define SGMII_LINK_MAC_MAC_FORCED	2
 #define SGMII_LINK_MAC_FIBER		3
 #define SGMII_LINK_MAC_PHY_NO_MDIO	4
+#define RGMII_LINK_MAC_PHY		5
+#define RGMII_LINK_MAC_MAC_FORCED	6
+#define RGMII_LINK_MAC_PHY_NO_MDIO	7
 #define XGMII_LINK_MAC_PHY		10
 #define XGMII_LINK_MAC_MAC_FORCED	11
 
diff --git a/drivers/net/ethernet/ti/netcp_ethss.c b/drivers/net/ethernet/ti/netcp_ethss.c
index 56dbc0b..df163ec 100644
--- a/drivers/net/ethernet/ti/netcp_ethss.c
+++ b/drivers/net/ethernet/ti/netcp_ethss.c
@@ -21,6 +21,7 @@
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of_mdio.h>
+#include <linux/of_net.h>
 #include <linux/of_address.h>
 #include <linux/if_vlan.h>
 #include <linux/ptp_classify.h>
@@ -166,6 +167,9 @@
 #define	GBE_RXHOOK_ORDER			0
 #define GBE_DEFAULT_ALE_AGEOUT			30
 #define SLAVE_LINK_IS_XGMII(s) ((s)->link_interface >= XGMII_LINK_MAC_PHY)
+#define SLAVE_LINK_IS_RGMII(s) \
+	(((s)->link_interface >= RGMII_LINK_MAC_PHY) && \
+	 ((s)->link_interface <= RGMII_LINK_MAC_PHY_NO_MDIO))
 #define NETCP_LINK_STATE_INVALID		-1
 
 #define GBE_SET_REG_OFS(p, rb, rn) p->rb##_ofs.rn = \
@@ -549,6 +553,7 @@ struct gbe_ss_regs {
 struct gbe_ss_regs_ofs {
 	u16	id_ver;
 	u16	control;
+	u16	rgmii_status; /* 2U */
 };
 
 struct gbe_switch_regs {
@@ -591,6 +596,7 @@ struct gbe_port_regs {
 struct gbe_port_regs_ofs {
 	u16	port_vlan;
 	u16	tx_pri_map;
+	u16     rx_pri_map;
 	u16	sa_lo;
 	u16	sa_hi;
 	u16	ts_ctl;
@@ -695,6 +701,7 @@ struct gbe_slave {
 	u32				link_interface;
 	u32				mac_control;
 	u8				phy_port_t;
+	struct device_node		*node;
 	struct device_node		*phy_node;
 	struct ts_ctl                   ts_ctl;
 	struct list_head		slave_list;
@@ -2091,8 +2098,9 @@ static void netcp_ethss_link_state_action(struct gbe_priv *gbe_dev,
 				     ALE_PORT_STATE_FORWARD);
 
 		if (ndev && slave->open &&
-		    slave->link_interface != SGMII_LINK_MAC_PHY &&
-		    slave->link_interface != XGMII_LINK_MAC_PHY)
+		    ((slave->link_interface != SGMII_LINK_MAC_PHY) &&
+		    (slave->link_interface != RGMII_LINK_MAC_PHY) &&
+		    (slave->link_interface != XGMII_LINK_MAC_PHY)))
 			netif_carrier_on(ndev);
 	} else {
 		writel(mac_control, GBE_REG_ADDR(slave, emac_regs,
@@ -2101,8 +2109,9 @@ static void netcp_ethss_link_state_action(struct gbe_priv *gbe_dev,
 				     ALE_PORT_STATE,
 				     ALE_PORT_STATE_DISABLE);
 		if (ndev &&
-		    slave->link_interface != SGMII_LINK_MAC_PHY &&
-		    slave->link_interface != XGMII_LINK_MAC_PHY)
+		    ((slave->link_interface != SGMII_LINK_MAC_PHY) &&
+		    (slave->link_interface != RGMII_LINK_MAC_PHY) &&
+		    (slave->link_interface != XGMII_LINK_MAC_PHY)))
 			netif_carrier_off(ndev);
 	}
 
@@ -2115,23 +2124,39 @@ static bool gbe_phy_link_status(struct gbe_slave *slave)
 	 return !slave->phy || slave->phy->link;
 }
 
+#define RGMII_REG_STATUS_LINK	BIT(0)
+
+static void netcp_2u_rgmii_get_port_link(struct gbe_priv *gbe_dev, bool *status)
+{
+	u32 val = 0;
+
+	val = readl(GBE_REG_ADDR(gbe_dev, ss_regs, rgmii_status));
+	*status = false;
+	if ((val & RGMII_REG_STATUS_LINK) != 0)
+		*status = true;
+}
+
 static void netcp_ethss_update_link_state(struct gbe_priv *gbe_dev,
 					  struct gbe_slave *slave,
 					  struct net_device *ndev)
 {
-	int sp = slave->slave_num;
-	int phy_link_state, sgmii_link_state = 1, link_state;
+	bool sw_link_state = true, phy_link_state;
+	int sp = slave->slave_num, link_state;
 
 	if (!slave->open)
 		return;
 
 	if (!SLAVE_LINK_IS_XGMII(slave)) {
-		sgmii_link_state =
+		if (SLAVE_LINK_IS_RGMII(slave))
+			netcp_2u_rgmii_get_port_link(gbe_dev,
+						     &sw_link_state);
+		else
+			sw_link_state =
 			netcp_sgmii_get_port_link(SGMII_BASE(gbe_dev, sp), sp);
 	}
 
 	phy_link_state = gbe_phy_link_status(slave);
-	link_state = phy_link_state & sgmii_link_state;
+	link_state = phy_link_state & sw_link_state;
 
 	if (atomic_xchg(&slave->link_state, link_state) != link_state)
 		netcp_ethss_link_state_action(gbe_dev, ndev, slave,
@@ -2271,11 +2296,19 @@ static int gbe_slave_open(struct gbe_intf *gbe_intf)
 
 	void (*hndlr)(struct net_device *) = gbe_adjust_link;
 
-	gbe_sgmii_config(priv, slave);
+	if ((priv->ss_version == GBE_SS_VERSION_14) || IS_SS_ID_NU(priv))
+		gbe_sgmii_config(priv, slave);
 	gbe_port_reset(slave);
 	gbe_sgmii_rtreset(priv, slave, false);
 	gbe_port_config(priv, slave, priv->rx_packet_max);
 	gbe_set_slave_mac(slave, gbe_intf);
+	/* For NU & 2U switch, map the vlan priorities to zero
+	 * as we only configure to use priority 0
+	 */
+	if (IS_SS_ID_MU(priv))
+		writel(HOST_TX_PRI_MAP_DEFAULT,
+		       GBE_REG_ADDR(slave, port_regs, rx_pri_map));
+
 	/* enable forwarding */
 	cpsw_ale_control_set(priv->ale, slave->port_num,
 			     ALE_PORT_STATE, ALE_PORT_STATE_FORWARD);
@@ -2286,6 +2319,15 @@ static int gbe_slave_open(struct gbe_intf *gbe_intf)
 		has_phy = true;
 		phy_mode = PHY_INTERFACE_MODE_SGMII;
 		slave->phy_port_t = PORT_MII;
+	} else if (slave->link_interface == RGMII_LINK_MAC_PHY) {
+		has_phy = true;
+		phy_mode = of_get_phy_mode(slave->node);
+		/* if phy-mode is not present, default to
+		 * PHY_INTERFACE_MODE_RGMII
+		 */
+		if (phy_mode < 0)
+			phy_mode = PHY_INTERFACE_MODE_RGMII;
+		slave->phy_port_t = PORT_MII;
 	} else if (slave->link_interface == XGMII_LINK_MAC_PHY) {
 		has_phy = true;
 		phy_mode = PHY_INTERFACE_MODE_NA;
@@ -2911,8 +2953,10 @@ static int init_slave(struct gbe_priv *gbe_dev, struct gbe_slave *slave,
 		slave->link_interface = SGMII_LINK_MAC_PHY;
 	}
 
+	slave->node = node;
 	slave->open = false;
 	if ((slave->link_interface == SGMII_LINK_MAC_PHY) ||
+	    (slave->link_interface == RGMII_LINK_MAC_PHY) ||
 	    (slave->link_interface == XGMII_LINK_MAC_PHY))
 		slave->phy_node = of_parse_phandle(node, "phy-handle", 0);
 	slave->port_num = gbe_get_slave_port(gbe_dev, slave->slave_num);
@@ -2976,6 +3020,7 @@ static int init_slave(struct gbe_priv *gbe_dev, struct gbe_slave *slave,
 		/* Initialize  slave port register offsets */
 		GBENU_SET_REG_OFS(slave, port_regs, port_vlan);
 		GBENU_SET_REG_OFS(slave, port_regs, tx_pri_map);
+		GBENU_SET_REG_OFS(slave, port_regs, rx_pri_map);
 		GBENU_SET_REG_OFS(slave, port_regs, sa_lo);
 		GBENU_SET_REG_OFS(slave, port_regs, sa_hi);
 		GBENU_SET_REG_OFS(slave, port_regs, ts_ctl);
@@ -3039,7 +3084,9 @@ static void init_secondary_ports(struct gbe_priv *gbe_dev,
 			continue;
 		}
 
-		gbe_sgmii_config(gbe_dev, slave);
+		if ((gbe_dev->ss_version == GBE_SS_VERSION_14) ||
+		    IS_SS_ID_NU(gbe_dev))
+			gbe_sgmii_config(gbe_dev, slave);
 		gbe_port_reset(slave);
 		gbe_port_config(gbe_dev, slave, gbe_dev->rx_packet_max);
 		list_add_tail(&slave->slave_list, &gbe_dev->secondary_slaves);
@@ -3073,6 +3120,9 @@ static void init_secondary_ports(struct gbe_priv *gbe_dev,
 	if (slave->link_interface == SGMII_LINK_MAC_PHY) {
 		phy_mode = PHY_INTERFACE_MODE_SGMII;
 		slave->phy_port_t = PORT_MII;
+	} else if (slave->link_interface == RGMII_LINK_MAC_PHY) {
+		phy_mode = PHY_INTERFACE_MODE_RGMII;
+		slave->phy_port_t = PORT_MII;
 	} else {
 		phy_mode = PHY_INTERFACE_MODE_NA;
 		slave->phy_port_t = PORT_FIBRE;
@@ -3080,6 +3130,7 @@ static void init_secondary_ports(struct gbe_priv *gbe_dev,
 
 	for_each_sec_slave(slave, gbe_dev) {
 		if ((slave->link_interface != SGMII_LINK_MAC_PHY) &&
+		    (slave->link_interface != RGMII_LINK_MAC_PHY) &&
 		    (slave->link_interface != XGMII_LINK_MAC_PHY))
 			continue;
 		slave->phy =
@@ -3355,7 +3406,7 @@ static int set_gbenu_ethss_priv(struct gbe_priv *gbe_dev,
 	gbe_dev->num_stats_mods = gbe_dev->max_num_ports;
 	gbe_dev->et_stats = gbenu_et_stats;
 
-	if (IS_SS_ID_NU(gbe_dev))
+	if (IS_SS_ID_MU(gbe_dev))
 		gbe_dev->num_et_stats = GBENU_ET_STATS_HOST_SIZE +
 			(gbe_dev->max_num_slaves * GBENU_ET_STATS_PORT_SIZE);
 	else
@@ -3419,6 +3470,8 @@ static int set_gbenu_ethss_priv(struct gbe_priv *gbe_dev,
 
 	/* Subsystem registers */
 	GBENU_SET_REG_OFS(gbe_dev, ss_regs, id_ver);
+	/* ok to set for MU, but used by 2U only */
+	GBENU_SET_REG_OFS(gbe_dev, ss_regs, rgmii_status);
 
 	/* Switch module registers */
 	GBENU_SET_REG_OFS(gbe_dev, switch_regs, id_ver);
-- 
1.9.1

^ permalink raw reply related	[flat|nested] 13+ messages in thread

* [net-next PATCH 4/5] Revert "net: netcp: remove dead code from the driver"
  2018-03-26 20:15 [net-next PATCH 0/5] Add support for netcp driver on K2G SoC Murali Karicheri
                   ` (2 preceding siblings ...)
  2018-03-26 20:15 ` [net-next PATCH 3/5] net: netcp: ethss enhancements to support 2u cpsw h/w on K2G SoC Murali Karicheri
@ 2018-03-26 20:15 ` Murali Karicheri
  2018-03-26 20:15 ` [net-next PATCH 5/5] net: netcp: support probe deferral Murali Karicheri
  4 siblings, 0 replies; 13+ messages in thread
From: Murali Karicheri @ 2018-03-26 20:15 UTC (permalink / raw)
  To: robh+dt, mark.rutland, ssantosh, malat, w-kwok2, devicetree,
	linux-kernel, linux-arm-kernel, davem, netdev

As the probe sequence is not guaranteed contrary to the assumption
of the commit 2d8e276a9030, same has to be reverted.

commit 2d8e276a9030 ("net: netcp: remove dead code from the driver")

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
---
 drivers/net/ethernet/ti/netcp_core.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/net/ethernet/ti/netcp_core.c b/drivers/net/ethernet/ti/netcp_core.c
index f5a7eb2..9c51b25 100644
--- a/drivers/net/ethernet/ti/netcp_core.c
+++ b/drivers/net/ethernet/ti/netcp_core.c
@@ -2155,6 +2155,7 @@ static int netcp_probe(struct platform_device *pdev)
 	struct device_node *child, *interfaces;
 	struct netcp_device *netcp_device;
 	struct device *dev = &pdev->dev;
+	struct netcp_module *module;
 	int ret;
 
 	if (!node) {
@@ -2203,6 +2204,14 @@ static int netcp_probe(struct platform_device *pdev)
 	/* Add the device instance to the list */
 	list_add_tail(&netcp_device->device_list, &netcp_devices);
 
+	/* Probe & attach any modules already registered */
+	mutex_lock(&netcp_modules_lock);
+	for_each_netcp_module(module) {
+		ret = netcp_module_probe(netcp_device, module);
+		if (ret < 0)
+			dev_err(dev, "module(%s) probe failed\n", module->name);
+	}
+	mutex_unlock(&netcp_modules_lock);
 	return 0;
 
 probe_quit_interface:
-- 
1.9.1

^ permalink raw reply related	[flat|nested] 13+ messages in thread

* [net-next PATCH 5/5] net: netcp: support probe deferral
  2018-03-26 20:15 [net-next PATCH 0/5] Add support for netcp driver on K2G SoC Murali Karicheri
                   ` (3 preceding siblings ...)
  2018-03-26 20:15 ` [net-next PATCH 4/5] Revert "net: netcp: remove dead code from the driver" Murali Karicheri
@ 2018-03-26 20:15 ` Murali Karicheri
  4 siblings, 0 replies; 13+ messages in thread
From: Murali Karicheri @ 2018-03-26 20:15 UTC (permalink / raw)
  To: robh+dt, mark.rutland, ssantosh, malat, w-kwok2, devicetree,
	linux-kernel, linux-arm-kernel, davem, netdev

The netcp driver shouldn't proceed until the knav qmss and dma
devices are ready. So return -EPROBE_DEFER if these devices are not
ready.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
---
 drivers/net/ethernet/ti/netcp_core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/ti/netcp_core.c b/drivers/net/ethernet/ti/netcp_core.c
index 9c51b25..736f6f7 100644
--- a/drivers/net/ethernet/ti/netcp_core.c
+++ b/drivers/net/ethernet/ti/netcp_core.c
@@ -2158,6 +2158,10 @@ static int netcp_probe(struct platform_device *pdev)
 	struct netcp_module *module;
 	int ret;
 
+	if (!knav_dma_device_ready() ||
+	    !knav_qmss_device_ready())
+		return -EPROBE_DEFER;
+
 	if (!node) {
 		dev_err(dev, "could not find device info\n");
 		return -ENODEV;
-- 
1.9.1

^ permalink raw reply related	[flat|nested] 13+ messages in thread

* Re: [net-next PATCH 3/5] net: netcp: ethss enhancements to support 2u cpsw h/w on K2G SoC
  2018-03-26 20:15 ` [net-next PATCH 3/5] net: netcp: ethss enhancements to support 2u cpsw h/w on K2G SoC Murali Karicheri
@ 2018-03-26 20:28   ` Andrew Lunn
  2018-03-27 13:23     ` Murali Karicheri
  0 siblings, 1 reply; 13+ messages in thread
From: Andrew Lunn @ 2018-03-26 20:28 UTC (permalink / raw)
  To: Murali Karicheri
  Cc: robh+dt, mark.rutland, ssantosh, malat, w-kwok2, devicetree,
	linux-kernel, linux-arm-kernel, davem, netdev

On Mon, Mar 26, 2018 at 04:15:10PM -0400, Murali Karicheri wrote:
> K2G SoC uses 2u cpsw h/w. It uses RGMII instead of SGMII to interface with
> Phy. This patch enhances the driver to check RGMII status instead of SGMII
> status for link state determination. Also map all of the vlan priorities
> to zero as the packet DMA is enabled to receive only flow id 0 which maps
> to priority zero.
> 
> Additionally, When a phy with rgmii interface requires internal delay, the
> same is set in the phy driver. To support such phy devices, add a phy-mode
> handling code in the driver using of_get_phy_mode() and pass the obtained
> phy mode to of_phy_connect()

Hi Murali

Please break this patch up. One patch should do one thing. That makes
it easy to review. There are too many things going on at once here.

   Andrew

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [net-next PATCH 2/5] soc: ti: K2G: provide APIs to support driver probe deferral
  2018-03-26 20:15 ` [net-next PATCH 2/5] soc: ti: K2G: provide APIs to support driver probe deferral Murali Karicheri
@ 2018-03-26 20:48   ` Andrew Lunn
  2018-03-27 13:32     ` Murali Karicheri
  0 siblings, 1 reply; 13+ messages in thread
From: Andrew Lunn @ 2018-03-26 20:48 UTC (permalink / raw)
  To: Murali Karicheri
  Cc: robh+dt, mark.rutland, ssantosh, malat, w-kwok2, devicetree,
	linux-kernel, linux-arm-kernel, davem, netdev

On Mon, Mar 26, 2018 at 04:15:09PM -0400, Murali Karicheri wrote:
> This patch provide APIs to allow client drivers to support
> probe deferral. On K2G SoC, devices can be probed only
> after the ti_sci_pm_domains driver is probed and ready.
> As drivers may get probed at different order, any driver
> that depends on knav dma and qmss drivers, for example
> netcp network driver, needs to defer probe until
> knav devices are probed and ready to service. To do this,
> add an API to query the device ready status from the knav
> dma and qmss devices.

Hi Murali 

Shouldn't you really re-write this to be a dma driver?  You would then
do something like of_dma_request_slave_channel() in the ethernet
driver probe function. That probably correctly returns EPROBE_DEFER.

       Andrew

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [net-next PATCH 3/5] net: netcp: ethss enhancements to support 2u cpsw h/w on K2G SoC
  2018-03-26 20:28   ` Andrew Lunn
@ 2018-03-27 13:23     ` Murali Karicheri
  2018-03-27 13:47       ` Andrew Lunn
  0 siblings, 1 reply; 13+ messages in thread
From: Murali Karicheri @ 2018-03-27 13:23 UTC (permalink / raw)
  To: Andrew Lunn
  Cc: robh+dt, mark.rutland, ssantosh, malat, w-kwok2, devicetree,
	linux-kernel, linux-arm-kernel, davem, netdev

On 03/26/2018 04:28 PM, Andrew Lunn wrote:
> On Mon, Mar 26, 2018 at 04:15:10PM -0400, Murali Karicheri wrote:
>> K2G SoC uses 2u cpsw h/w. It uses RGMII instead of SGMII to interface with
>> Phy. This patch enhances the driver to check RGMII status instead of SGMII
>> status for link state determination. Also map all of the vlan priorities
>> to zero as the packet DMA is enabled to receive only flow id 0 which maps
>> to priority zero.
>>
>> Additionally, When a phy with rgmii interface requires internal delay, the
>> same is set in the phy driver. To support such phy devices, add a phy-mode
>> handling code in the driver using of_get_phy_mode() and pass the obtained
>> phy mode to of_phy_connect()
> 
> Hi Murali
> 
> Please break this patch up. One patch should do one thing. That makes
> it easy to review. There are too many things going on at once here.
> 
>    Andrew
> 
Hello Andrew,

Thanks for the comment. But I am not sure how to break this up as this is 
an enhancement to the driver to support a newer version of the cspw 
hardware. Without all these pieces together, the driver can't
function. Probably I can make the below break up based on different functions
added. Let me know if this looks good to you. Beware that patch #2 and
#3 are small patches and majority of code change will be in patch #1
which has to go together. 

Patch #1. Add support new link interface, RGMII_LINK_MAC_PHY, for K2G
          - Most of the code is for this
Patch #2. Add support for configuring phy_mode 
          - This just add phy_mode handling code 
Patch #3. map all vlan priorities to flow id 0

-- 
Murali Karicheri
Linux Kernel, Keystone

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [net-next PATCH 2/5] soc: ti: K2G: provide APIs to support driver probe deferral
  2018-03-26 20:48   ` Andrew Lunn
@ 2018-03-27 13:32     ` Murali Karicheri
  2018-03-27 14:03       ` Andrew Lunn
  0 siblings, 1 reply; 13+ messages in thread
From: Murali Karicheri @ 2018-03-27 13:32 UTC (permalink / raw)
  To: Andrew Lunn
  Cc: robh+dt, mark.rutland, ssantosh, malat, w-kwok2, devicetree,
	linux-kernel, linux-arm-kernel, davem, netdev

Hello Andrew,

On 03/26/2018 04:48 PM, Andrew Lunn wrote:
> On Mon, Mar 26, 2018 at 04:15:09PM -0400, Murali Karicheri wrote:
>> This patch provide APIs to allow client drivers to support
>> probe deferral. On K2G SoC, devices can be probed only
>> after the ti_sci_pm_domains driver is probed and ready.
>> As drivers may get probed at different order, any driver
>> that depends on knav dma and qmss drivers, for example
>> netcp network driver, needs to defer probe until
>> knav devices are probed and ready to service. To do this,
>> add an API to query the device ready status from the knav
>> dma and qmss devices.
> 
> Hi Murali 
> 
> Shouldn't you really re-write this to be a dma driver?  You would then
> do something like of_dma_request_slave_channel() in the ethernet
> driver probe function. That probably correctly returns EPROBE_DEFER.
> 
>        Andrew
> 

Could you please elaborate? These knav dma and qmss drivers are
introduced to support packet DMA hardware available in Keystone
NetCP which couldn't be implemented using the DMA APIs available
at the time this driver was introduced. Another reason was that
the performance was really bad. We had an internal implementation
based on DMA API before which couldn't be upstreamed at that time
due to the reason that we were mis-using the API for this driver.
So we introduced these knav_dma driver to support NetCP. We don't
have any plan to re-write the driver at this time.

If your question is about EPROBE_DEFER being returned from an
existing knav_dma API and using the return code to achieve probe
defer instead of introducing these APIs, I can take a look into
that and respond. So please clarify.

-- 
Murali Karicheri
Linux Kernel, Keystone

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [net-next PATCH 3/5] net: netcp: ethss enhancements to support 2u cpsw h/w on K2G SoC
  2018-03-27 13:23     ` Murali Karicheri
@ 2018-03-27 13:47       ` Andrew Lunn
  0 siblings, 0 replies; 13+ messages in thread
From: Andrew Lunn @ 2018-03-27 13:47 UTC (permalink / raw)
  To: Murali Karicheri
  Cc: robh+dt, mark.rutland, ssantosh, malat, w-kwok2, devicetree,
	linux-kernel, linux-arm-kernel, davem, netdev

> Hello Andrew,
> 
> Thanks for the comment. But I am not sure how to break this up as this is 
> an enhancement to the driver to support a newer version of the cspw 
> hardware. Without all these pieces together, the driver can't
> function.

Hi Murali

A few things to consider.

1) You can introduce new features needed by the new hardware one piece
at a time. The new hardware will then work when all the pieces have
been added. This is fine, the new hardware never worked before, so you
are not breaking anything.

2) Your changes could break the old hardware. By having lots of small
changes, you can do a git bissect and find which of the small changes
broke it.

3) It is much easier to review 10 small obviously correct patches than
one huge complex patch, which is not obvious.

> Probably I can make the below break up based on different functions
> added. Let me know if this looks good to you. Beware that patch #2 and
> #3 are small patches and majority of code change will be in patch #1
> which has to go together. 
> 
> Patch #1. Add support new link interface, RGMII_LINK_MAC_PHY, for K2G
>           - Most of the code is for this
> Patch #2. Add support for configuring phy_mode 
>           - This just add phy_mode handling code 
> Patch #3. map all vlan priorities to flow id 0

That sounds better.

Thanks
	Andrew

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [net-next PATCH 2/5] soc: ti: K2G: provide APIs to support driver probe deferral
  2018-03-27 13:32     ` Murali Karicheri
@ 2018-03-27 14:03       ` Andrew Lunn
  2018-03-27 14:31         ` Murali Karicheri
  0 siblings, 1 reply; 13+ messages in thread
From: Andrew Lunn @ 2018-03-27 14:03 UTC (permalink / raw)
  To: Murali Karicheri
  Cc: robh+dt, mark.rutland, ssantosh, malat, w-kwok2, devicetree,
	linux-kernel, linux-arm-kernel, davem, netdev

> Could you please elaborate? These knav dma and qmss drivers are
> introduced to support packet DMA hardware available in Keystone
> NetCP which couldn't be implemented using the DMA APIs available
> at the time this driver was introduced. Another reason was that
> the performance was really bad. We had an internal implementation
> based on DMA API before which couldn't be upstreamed at that time
> due to the reason that we were mis-using the API for this driver.
> So we introduced these knav_dma driver to support NetCP. We don't
> have any plan to re-write the driver at this time.
> 
> If your question is about EPROBE_DEFER being returned from an
> existing knav_dma API and using the return code to achieve probe
> defer instead of introducing these APIs, I can take a look into
> that and respond. So please clarify.
 
Hi Murali

So if i understood you right, at the time these drivers were written,
the linux DMA API did not do what you wanted. You could hack something
together by using the API wrongly, but that could not be mainlined. So
rather than fixing the DMA API to make it work for this hardware, you
ignored it, and made up your own API? This API now has its own
problems, it does not correctly handle ordering? So you are hacking
your own API further.

Does the Linux DMA API correctly handle probing order issues? Has the
Linux DMA API evolved so that it now does do what is needed by your
hardware?

If this was an old hardware which is slowly going away, it would not
be an issue. But it seems like there are new variants of the hardware
being released. So maybe you should go back and re-write the DMA
driver, rather than paper over the cracks?

	Andrew

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [net-next PATCH 2/5] soc: ti: K2G: provide APIs to support driver probe deferral
  2018-03-27 14:03       ` Andrew Lunn
@ 2018-03-27 14:31         ` Murali Karicheri
  0 siblings, 0 replies; 13+ messages in thread
From: Murali Karicheri @ 2018-03-27 14:31 UTC (permalink / raw)
  To: Andrew Lunn
  Cc: robh+dt, mark.rutland, ssantosh, malat, w-kwok2, devicetree,
	linux-kernel, linux-arm-kernel, davem, netdev

Hello Andrew,

On 03/27/2018 10:03 AM, Andrew Lunn wrote:
>> Could you please elaborate? These knav dma and qmss drivers are
>> introduced to support packet DMA hardware available in Keystone
>> NetCP which couldn't be implemented using the DMA APIs available
>> at the time this driver was introduced. Another reason was that
>> the performance was really bad. We had an internal implementation
>> based on DMA API before which couldn't be upstreamed at that time
>> due to the reason that we were mis-using the API for this driver.
>> So we introduced these knav_dma driver to support NetCP. We don't
>> have any plan to re-write the driver at this time.
>>
>> If your question is about EPROBE_DEFER being returned from an
>> existing knav_dma API and using the return code to achieve probe
>> defer instead of introducing these APIs, I can take a look into
>> that and respond. So please clarify.
>  
> Hi Murali
> 
> So if i understood you right, at the time these drivers were written,
> the linux DMA API did not do what you wanted. You could hack something
> together by using the API wrongly, but that could not be mainlined. So
> rather than fixing the DMA API to make it work for this hardware, you
> ignored it, and made up your own API? This API now has its own
> problems, it does not correctly handle ordering? So you are hacking
> your own API further.
> 
> Does the Linux DMA API correctly handle probing order issues? Has the
> Linux DMA API evolved so that it now does do what is needed by your
> hardware?
> 

Thanks once again for your review and response!

I don't think dma API was meant to support hardware like pkt dma and was the
reason quoted when this driver was introduced and the same is valid even
today. AFAIK, Without hacking the API, we will not be able to support our
driver even today. Besides Keystone itself is an old platform that is
matured and have been there for long. K2G SoC was also introduced almost
3 years ago and we were late to port it to upstream due to various reasons.
We now have the SoC and most of the drivers upstreamed and this is a
missing driver to support networking. Given that we don't have any other
new devices planned from this SoC familty in the future, and the platform
itself is old and matured, I don't think the extra effort needed to
explore DMA API usage and re-write the driver is justified. 

knav dma API is a TI SoC specific driver API and IMO, it should be fine\
to extend it to support probe deferral. I have also looked at the driver
and I don't see any other way to handle this since the channels are
allocated and used in ndo_open() and EPROBE_DEFER is not useful here.

Btw, I will re-write patch 3/5 as you have suggested as there is scope
for adding one more patch besides what I have mentioned in my response.
I will be sending v2 of the series soon with your comment on 3/5 addressed.

Regards,

Murali
> If this was an old hardware which is slowly going away, it would not
> be an issue. But it seems like there are new variants of the hardware
> being released. So maybe you should go back and re-write the DMA
> driver, rather than paper over the cracks?
> 
> 	Andrew
> 


-- 
Murali Karicheri
Linux Kernel, Keystone

^ permalink raw reply	[flat|nested] 13+ messages in thread

end of thread, other threads:[~2018-03-27 14:29 UTC | newest]

Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-03-26 20:15 [net-next PATCH 0/5] Add support for netcp driver on K2G SoC Murali Karicheri
2018-03-26 20:15 ` [net-next PATCH 1/5] soc: ti: K2G: enhancement to support QMSS in NSS Murali Karicheri
2018-03-26 20:15 ` [net-next PATCH 2/5] soc: ti: K2G: provide APIs to support driver probe deferral Murali Karicheri
2018-03-26 20:48   ` Andrew Lunn
2018-03-27 13:32     ` Murali Karicheri
2018-03-27 14:03       ` Andrew Lunn
2018-03-27 14:31         ` Murali Karicheri
2018-03-26 20:15 ` [net-next PATCH 3/5] net: netcp: ethss enhancements to support 2u cpsw h/w on K2G SoC Murali Karicheri
2018-03-26 20:28   ` Andrew Lunn
2018-03-27 13:23     ` Murali Karicheri
2018-03-27 13:47       ` Andrew Lunn
2018-03-26 20:15 ` [net-next PATCH 4/5] Revert "net: netcp: remove dead code from the driver" Murali Karicheri
2018-03-26 20:15 ` [net-next PATCH 5/5] net: netcp: support probe deferral Murali Karicheri

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