All of lore.kernel.org
 help / color / mirror / Atom feed
From: Antti Laakso <antti.laakso@linux.intel.com>
To: linux-media@vger.kernel.org, mchehab@kernel.org,
	sakari.ailus@linux.intel.com
Cc: daxing.li@intel.com, ong.hock.yu@intel.com, antti.laakso@linux.intel.com
Subject: [PATCH v2 10/44] media: ipu6: Use single struct for registers
Date: Fri, 21 Aug 2026 14:42:28 +0300	[thread overview]
Message-ID: <20260821114302.365532-11-antti.laakso@linux.intel.com> (raw)
In-Reply-To: <20260821114302.365532-1-antti.laakso@linux.intel.com>

Move register values from ipu6_buttress_ipc struct to
ipu6_buttress_registers as these are different in future
hardware versions as well.

Signed-off-by: Antti Laakso <antti.laakso@linux.intel.com>
---
 drivers/media/pci/intel/ipu6/ipu6-buttress.c | 86 +++++++++-----------
 drivers/media/pci/intel/ipu6/ipu6-buttress.h | 17 ++--
 drivers/media/pci/intel/ipu6/ipu6.c          | 13 +--
 3 files changed, 54 insertions(+), 62 deletions(-)

diff --git a/drivers/media/pci/intel/ipu6/ipu6-buttress.c b/drivers/media/pci/intel/ipu6/ipu6-buttress.c
index 3c5f4e407b7c..e77a569bb97e 100644
--- a/drivers/media/pci/intel/ipu6/ipu6-buttress.c
+++ b/drivers/media/pci/intel/ipu6/ipu6-buttress.c
@@ -55,11 +55,11 @@
 
 #define BUTTRESS_MAX_CONSECUTIVE_IRQS	100
 
-int ipu6_buttress_ipc_reset(struct ipu6_device *isp,
-			    struct ipu6_buttress_ipc *ipc)
+int ipu6_buttress_ipc_reset(struct ipu6_device *isp)
 {
 	unsigned int retries = BUTTRESS_IPC_RESET_RETRY;
 	struct ipu6_buttress *b = &isp->buttress;
+	const struct ipu6_buttress_registers *regs = b->regs;
 	u32 val = 0, csr_in_clr;
 
 	if (!isp->secure_mode) {
@@ -70,11 +70,11 @@ int ipu6_buttress_ipc_reset(struct ipu6_device *isp,
 	mutex_lock(&b->ipc_mutex);
 
 	/* Clear-by-1 CSR (all bits), corresponding internal states. */
-	val = readl(isp->base + ipc->csr_in);
-	writel(val, isp->base + ipc->csr_in);
+	val = readl(isp->base + regs->csr_in);
+	writel(val, isp->base + regs->csr_in);
 
 	/* Set peer CSR bit IPC_PEER_COMP_ACTIONS_RST_PHASE1 */
-	writel(ENTRY, isp->base + ipc->csr_out);
+	writel(ENTRY, isp->base + regs->csr_out);
 	/*
 	 * Clear-by-1 all CSR bits EXCEPT following
 	 * bits:
@@ -89,7 +89,7 @@ int ipu6_buttress_ipc_reset(struct ipu6_device *isp,
 
 	do {
 		usleep_range(400, 500);
-		val = readl(isp->base + ipc->csr_in);
+		val = readl(isp->base + regs->csr_in);
 		switch (val) {
 		case ENTRY | EXIT:
 		case ENTRY | EXIT | QUERY:
@@ -100,8 +100,8 @@ int ipu6_buttress_ipc_reset(struct ipu6_device *isp,
 			 * 2) Set peer CSR bit
 			 * IPC_PEER_QUERIED_IP_COMP_ACTIONS_RST_PHASE.
 			 */
-			writel(ENTRY | EXIT, isp->base + ipc->csr_in);
-			writel(QUERY, isp->base + ipc->csr_out);
+			writel(ENTRY | EXIT, isp->base + regs->csr_in);
+			writel(QUERY, isp->base + regs->csr_out);
 			break;
 		case ENTRY:
 		case ENTRY | QUERY:
@@ -112,8 +112,8 @@ int ipu6_buttress_ipc_reset(struct ipu6_device *isp,
 			 * 2) Set peer CSR bit
 			 * IPC_PEER_COMP_ACTIONS_RST_PHASE1.
 			 */
-			writel(ENTRY | QUERY, isp->base + ipc->csr_in);
-			writel(ENTRY, isp->base + ipc->csr_out);
+			writel(ENTRY | QUERY, isp->base + regs->csr_in);
+			writel(ENTRY, isp->base + regs->csr_out);
 			break;
 		case EXIT:
 		case EXIT | QUERY:
@@ -130,17 +130,17 @@ int ipu6_buttress_ipc_reset(struct ipu6_device *isp,
 			 * 3) Set peer CSR bit
 			 * IPC_PEER_COMP_ACTIONS_RST_PHASE2.
 			 */
-			writel(EXIT, isp->base + ipc->csr_in);
-			writel(0, isp->base + ipc->db0_in);
-			writel(csr_in_clr, isp->base + ipc->csr_in);
-			writel(EXIT, isp->base + ipc->csr_out);
+			writel(EXIT, isp->base + regs->csr_in);
+			writel(0, isp->base + regs->db0_in);
+			writel(csr_in_clr, isp->base + regs->csr_in);
+			writel(EXIT, isp->base + regs->csr_out);
 
 			/*
 			 * Read csr_in again to make sure if RST_PHASE2 is done.
 			 * If csr_in is QUERY, it should be handled again.
 			 */
 			usleep_range(200, 300);
-			val = readl(isp->base + ipc->csr_in);
+			val = readl(isp->base + regs->csr_in);
 			if (val & QUERY) {
 				dev_dbg(&isp->pdev->dev,
 					"RST_PHASE2 retry csr_in = %x\n", val);
@@ -155,8 +155,8 @@ int ipu6_buttress_ipc_reset(struct ipu6_device *isp,
 			 * 2) Set peer CSR bit
 			 * IPC_PEER_COMP_ACTIONS_RST_PHASE1
 			 */
-			writel(QUERY, isp->base + ipc->csr_in);
-			writel(ENTRY, isp->base + ipc->csr_out);
+			writel(QUERY, isp->base + regs->csr_in);
+			writel(ENTRY, isp->base + regs->csr_out);
 			break;
 		default:
 			dev_dbg_ratelimited(&isp->pdev->dev,
@@ -171,42 +171,42 @@ int ipu6_buttress_ipc_reset(struct ipu6_device *isp,
 	return -ETIMEDOUT;
 }
 
-static void ipu6_buttress_ipc_validity_close(struct ipu6_device *isp,
-					     struct ipu6_buttress_ipc *ipc)
+static void ipu6_buttress_ipc_validity_close(struct ipu6_device *isp)
 {
 	writel(BUTTRESS_IU2CSECSR_IPC_PEER_DEASSERTED_REG_VALID_REQ,
-	       isp->base + ipc->csr_out);
+	       isp->base + isp->buttress.regs->csr_out);
 }
 
 static int
-ipu6_buttress_ipc_validity_open(struct ipu6_device *isp,
-				struct ipu6_buttress_ipc *ipc)
+ipu6_buttress_ipc_validity_open(struct ipu6_device *isp)
 {
 	unsigned int mask = BUTTRESS_IU2CSECSR_IPC_PEER_ACKED_REG_VALID;
+	const struct ipu6_buttress_registers *regs = isp->buttress.regs;
 	void __iomem *addr;
 	int ret;
 	u32 val;
 
 	writel(BUTTRESS_IU2CSECSR_IPC_PEER_ASSERTED_REG_VALID_REQ,
-	       isp->base + ipc->csr_out);
+	       isp->base + regs->csr_out);
 
-	addr = isp->base + ipc->csr_in;
+	addr = isp->base + regs->csr_in;
 	ret = readl_poll_timeout(addr, val, val & mask, 200,
 				 BUTTRESS_IPC_VALIDITY_TIMEOUT_US);
 	if (ret) {
 		dev_err(&isp->pdev->dev, "CSE validity timeout 0x%x\n", val);
-		ipu6_buttress_ipc_validity_close(isp, ipc);
+		ipu6_buttress_ipc_validity_close(isp);
 	}
 
 	return ret;
 }
 
-static void ipu6_buttress_ipc_recv(struct ipu6_device *isp,
-				   struct ipu6_buttress_ipc *ipc, u32 *ipc_msg)
+static void ipu6_buttress_ipc_recv(struct ipu6_device *isp, u32 *ipc_msg)
 {
+	const struct ipu6_buttress_registers *regs = isp->buttress.regs;
+
 	if (ipc_msg)
-		*ipc_msg = readl(isp->base + ipc->data0_in);
-	writel(0, isp->base + ipc->db0_in);
+		*ipc_msg = readl(isp->base + regs->data0_in);
+	writel(0, isp->base + regs->db0_in);
 }
 
 static int ipu6_buttress_ipc_send_bulk(struct ipu6_device *isp,
@@ -217,13 +217,14 @@ static int ipu6_buttress_ipc_send_bulk(struct ipu6_device *isp,
 	unsigned int i, retry = BUTTRESS_IPC_CMD_SEND_RETRY;
 	struct ipu6_buttress *b = &isp->buttress;
 	struct ipu6_buttress_ipc *ipc = &b->ipc;
+	const struct ipu6_buttress_registers *regs = b->regs;
 	u32 val;
 	int ret;
 	int tout;
 
 	mutex_lock(&b->ipc_mutex);
 
-	ret = ipu6_buttress_ipc_validity_open(isp, ipc);
+	ret = ipu6_buttress_ipc_validity_open(isp);
 	if (ret) {
 		dev_err(&isp->pdev->dev, "IPC validity open failed\n");
 		goto out;
@@ -239,9 +240,9 @@ static int ipu6_buttress_ipc_send_bulk(struct ipu6_device *isp,
 
 		dev_dbg(&isp->pdev->dev, "bulk IPC command: 0x%x\n",
 			msgs[i].cmd);
-		writel(msgs[i].cmd, isp->base + ipc->data0_out);
+		writel(msgs[i].cmd, isp->base + regs->data0_out);
 		val = BUTTRESS_IU2CSEDB0_BUSY | msgs[i].cmd_size;
-		writel(val, isp->base + ipc->db0_out);
+		writel(val, isp->base + regs->db0_out);
 
 		tout = wait_for_completion_timeout(&ipc->send_complete,
 						   tx_timeout_jiffies);
@@ -253,7 +254,7 @@ static int ipu6_buttress_ipc_send_bulk(struct ipu6_device *isp,
 			}
 
 			/* Try again if CSE is not responding on first try */
-			writel(0, isp->base + ipc->db0_out);
+			writel(0, isp->base + regs->db0_out);
 			i--;
 			continue;
 		}
@@ -271,8 +272,8 @@ static int ipu6_buttress_ipc_send_bulk(struct ipu6_device *isp,
 			goto out;
 		}
 
-		if (ipc->nack_mask &&
-		    (ipc->recv_data & ipc->nack_mask) == ipc->nack) {
+		if ((ipc->recv_data & BUTTRESS_CSE2IUDATA0_IPC_NACK_MASK) ==
+		     BUTTRESS_CSE2IUDATA0_IPC_NACK) {
 			dev_err(&isp->pdev->dev,
 				"IPC NACK for cmd 0x%x\n", msgs[i].cmd);
 			ret = -EIO;
@@ -291,7 +292,7 @@ static int ipu6_buttress_ipc_send_bulk(struct ipu6_device *isp,
 	dev_dbg(&isp->pdev->dev, "bulk IPC commands done\n");
 
 out:
-	ipu6_buttress_ipc_validity_close(isp, ipc);
+	ipu6_buttress_ipc_validity_close(isp);
 	mutex_unlock(&b->ipc_mutex);
 	return ret;
 }
@@ -375,7 +376,7 @@ irqreturn_t ipu6_buttress_isr(int irq, void *isp_ptr)
 			dev_dbg(&isp->pdev->dev,
 				"BUTTRESS_ISR_IPC_FROM_CSE_IS_WAITING\n");
 
-			ipu6_buttress_ipc_recv(isp, &b->ipc, &b->ipc.recv_data);
+			ipu6_buttress_ipc_recv(isp, &b->ipc.recv_data);
 			complete(&b->ipc.recv_complete);
 		}
 
@@ -836,15 +837,6 @@ int ipu6_buttress_init(struct ipu6_device *isp)
 	init_completion(&b->ipc.send_complete);
 	init_completion(&b->ipc.recv_complete);
 
-	b->ipc.nack = BUTTRESS_CSE2IUDATA0_IPC_NACK;
-	b->ipc.nack_mask = BUTTRESS_CSE2IUDATA0_IPC_NACK_MASK;
-	b->ipc.csr_in = BUTTRESS_REG_CSE2IUCSR;
-	b->ipc.csr_out = BUTTRESS_REG_IU2CSECSR;
-	b->ipc.db0_in = BUTTRESS_REG_CSE2IUDB0;
-	b->ipc.db0_out = BUTTRESS_REG_IU2CSEDB0;
-	b->ipc.data0_in = BUTTRESS_REG_CSE2IUDATA0;
-	b->ipc.data0_out = BUTTRESS_REG_IU2CSEDATA0;
-
 	INIT_LIST_HEAD(&b->constraints);
 
 	isp->secure_mode = ipu6_buttress_get_secure_mode(isp);
@@ -880,7 +872,7 @@ int ipu6_buttress_init(struct ipu6_device *isp)
 
 	/* Retry couple of times in case of CSE initialization is delayed */
 	do {
-		ret = ipu6_buttress_ipc_reset(isp, &b->ipc);
+		ret = ipu6_buttress_ipc_reset(isp);
 		if (ret) {
 			dev_warn(&isp->pdev->dev,
 				 "IPC reset protocol failed, retrying\n");
diff --git a/drivers/media/pci/intel/ipu6/ipu6-buttress.h b/drivers/media/pci/intel/ipu6/ipu6-buttress.h
index 68586a32fda3..a3c23adede7b 100644
--- a/drivers/media/pci/intel/ipu6/ipu6-buttress.h
+++ b/drivers/media/pci/intel/ipu6/ipu6-buttress.h
@@ -31,15 +31,7 @@ struct ipu6_buttress_ctrl {
 struct ipu6_buttress_ipc {
 	struct completion send_complete;
 	struct completion recv_complete;
-	u32 nack;
-	u32 nack_mask;
 	u32 recv_data;
-	u32 csr_out;
-	u32 csr_in;
-	u32 db0_in;
-	u32 db0_out;
-	u32 data0_out;
-	u32 data0_in;
 };
 
 struct ipu6_buttress_registers {
@@ -55,6 +47,12 @@ struct ipu6_buttress_registers {
 	u32 tsc_lo;
 	u32 wdt;
 	u32 btrs_ctrl;
+	u32 csr_in;
+	u32 csr_out;
+	u32 db0_in;
+	u32 db0_out;
+	u32 data0_in;
+	u32 data0_out;
 
 	/* Bitmasks */
 	u32 irq_is;
@@ -83,8 +81,7 @@ struct ipu6_ipc_buttress_bulk_msg {
 	u8 cmd_size;
 };
 
-int ipu6_buttress_ipc_reset(struct ipu6_device *isp,
-			    struct ipu6_buttress_ipc *ipc);
+int ipu6_buttress_ipc_reset(struct ipu6_device *isp);
 int ipu6_buttress_map_fw_image(struct ipu6_bus_device *sys,
 			       const struct firmware *fw,
 			       struct sg_table *sgt);
diff --git a/drivers/media/pci/intel/ipu6/ipu6.c b/drivers/media/pci/intel/ipu6/ipu6.c
index 55e660fda421..7ac9c92744c0 100644
--- a/drivers/media/pci/intel/ipu6/ipu6.c
+++ b/drivers/media/pci/intel/ipu6/ipu6.c
@@ -241,6 +241,12 @@ static const struct ipu6_buttress_registers ipu6_buttress_regs = {
 	.tsc_lo		= BUTTRESS_REG_TSC_LO,
 	.wdt		= BUTTRESS_REG_WDT,
 	.btrs_ctrl	= BUTTRESS_REG_BTRS_CTRL,
+	.csr_in		= BUTTRESS_REG_CSE2IUCSR,
+	.csr_out	= BUTTRESS_REG_IU2CSECSR,
+	.db0_in		= BUTTRESS_REG_CSE2IUDB0,
+	.db0_out	= BUTTRESS_REG_IU2CSEDB0,
+	.data0_in	= BUTTRESS_REG_CSE2IUDATA0,
+	.data0_out	= BUTTRESS_REG_IU2CSEDATA0,
 
 	/* Bitmasks */
 	.irq_is		= BUTTRESS_ISR_IS_IRQ,
@@ -779,7 +785,6 @@ static int ipu6_resume(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 	struct ipu6_device *isp = pci_get_drvdata(pdev);
-	struct ipu6_buttress *b = &isp->buttress;
 	int ret;
 
 	/* Configure the arbitration mechanisms for VC requests */
@@ -791,7 +796,7 @@ static int ipu6_resume(struct device *dev)
 
 	ipu6_buttress_restore(isp);
 
-	ret = ipu6_buttress_ipc_reset(isp, &b->ipc);
+	ret = ipu6_buttress_ipc_reset(isp);
 	if (ret)
 		dev_err(&isp->pdev->dev, "IPC reset protocol failed!\n");
 
@@ -820,10 +825,8 @@ static int ipu6_runtime_resume(struct device *dev)
 	ipu6_buttress_restore(isp);
 
 	if (isp->need_ipc_reset) {
-		struct ipu6_buttress *b = &isp->buttress;
-
 		isp->need_ipc_reset = false;
-		ret = ipu6_buttress_ipc_reset(isp, &b->ipc);
+		ret = ipu6_buttress_ipc_reset(isp);
 		if (ret)
 			dev_err(&isp->pdev->dev, "IPC reset protocol failed\n");
 	}
-- 
2.55.0


  parent reply	other threads:[~2026-08-21 11:44 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-21 11:42 [PATCH v2 00/44] media: ipu6: Add support for ipu7 hardware Antti Laakso
2026-08-21 11:42 ` [PATCH v2 01/44] media: ipu6: Add helpers for IPU runtime variation Antti Laakso
2026-08-21 11:42 ` [PATCH v2 02/44] media: ipu6: Rename pointer to firmware context Antti Laakso
2026-08-21 11:42 ` [PATCH v2 03/44] media: ipu6: Rename buttress_ipc pointer Antti Laakso
2026-08-21 11:42 ` [PATCH v2 04/44] media: ipu6: Remove duplicate warnings in cpd validation Antti Laakso
2026-08-21 11:42 ` [PATCH v2 05/44] media: ipu6: Remove unused ipu6 firmware struct Antti Laakso
2026-08-21 11:42 ` [PATCH v2 06/44] media: ipu6: Cleanup ipu6_mmu_init() Antti Laakso
2026-08-21 11:42 ` [PATCH v2 07/44] media: ipu6: Simplify firmware com arguments Antti Laakso
2026-08-21 11:42 ` [PATCH v2 08/44] media: ipu6: Add helper to identify ipu7 Antti Laakso
2026-08-21 11:42 ` [PATCH v2 09/44] media: ipu6: Prepare buttress for ipu7 support Antti Laakso
2026-08-21 11:42 ` Antti Laakso [this message]
2026-08-21 11:42 ` [PATCH v2 11/44] media: ipu6: Rename IPU subsys ID Antti Laakso
2026-08-21 11:42 ` [PATCH v2 12/44] media: ipu6: Add ipu7 buttress support Antti Laakso
2026-08-21 11:42 ` [PATCH v2 13/44] media: ipu6: Prepare mmu driver for hw variation Antti Laakso
2026-08-21 11:42 ` [PATCH v2 14/44] media: ipu6: Add ipu7 mmu support Antti Laakso
2026-08-21 11:42 ` [PATCH v2 15/44] media: ipu6: Add ipu7 cpd handling Antti Laakso
2026-08-21 11:42 ` [PATCH v2 16/44] media: ipu6: Add check for pkg_dir before freeing Antti Laakso
2026-08-21 11:42 ` [PATCH v2 17/44] media: ipu6: Rename isys fw msg union Antti Laakso
2026-08-21 11:42 ` [PATCH v2 18/44] media: ipu6: Move isys isr handlers to fw file Antti Laakso
2026-08-21 11:42 ` [PATCH v2 19/44] media: ipu6: Move hw specific buffer handling down Antti Laakso
2026-08-21 11:42 ` [PATCH v2 20/44] media: ipu6: Isolate hw specific buffer handling Antti Laakso
2026-08-21 11:42 ` [PATCH v2 21/44] media: ipu6: Add isys firmware ops Antti Laakso
2026-08-21 11:42 ` [PATCH v2 22/44] media: ipu6: Add ipu7 fw start/stop functionality Antti Laakso
2026-08-21 11:42 ` [PATCH v2 23/44] media: ipu6: Add ipu7 fw com methods Antti Laakso
2026-08-21 11:42 ` [PATCH v2 24/44] media: ipu6: Add ipu7 fw isys ops Antti Laakso
2026-08-21 11:42 ` [PATCH v2 25/44] media: ipu6: Add ipu7 csi2 register definitions Antti Laakso
2026-08-21 11:42 ` [PATCH v2 26/44] media: ipu6: Add ipu7 isr handler Antti Laakso
2026-08-21 11:42 ` [PATCH v2 27/44] media: ipu6: Add ipu7 csi phy driver Antti Laakso
2026-08-21 11:42 ` [PATCH v2 28/44] media: ipu6: Split ipu6 csi2 stream enable/disable Antti Laakso
2026-08-21 11:42 ` [PATCH v2 29/44] media: ipu6: Add support for ipu7 csi2 receiver Antti Laakso
2026-08-21 11:42 ` [PATCH v2 30/44] media: ipu6: Parse bus type for ipu7 Antti Laakso
2026-08-21 11:42 ` [PATCH v2 31/44] media: ipu6: Enable ipu7 isys interrupts Antti Laakso
2026-08-21 11:42 ` [PATCH v2 32/44] media: ipu6: Skip watermark configuration for ipu7 Antti Laakso
2026-08-21 11:42 ` [PATCH v2 33/44] media: ipu6: The SPC init is valid only for ipu6 Antti Laakso
2026-08-21 11:42 ` [PATCH v2 34/44] media: ipu6: The VC arbitration mechanism is ipu6 only Antti Laakso
2026-08-21 11:42 ` [PATCH v2 35/44] media: ipu6: Move buttress mem alloc out from probe Antti Laakso
2026-08-21 11:42 ` [PATCH v2 36/44] media: ipu6: Read correct SKU ID for ipu7 Antti Laakso
2026-08-21 11:42 ` [PATCH v2 37/44] media: ipu6: Add support for fixed iova region Antti Laakso
2026-08-21 11:42 ` [PATCH v2 38/44] media: ipu6: Make fw mapping function reusable Antti Laakso
2026-08-21 11:42 ` [PATCH v2 39/44] media: ipu6: Move isys fw mapping to pci_probe Antti Laakso
2026-08-21 18:17   ` Sakari Ailus
2026-08-21 11:42 ` [PATCH v2 40/44] media: ipu6: Map ipu7 firmware Antti Laakso
2026-08-21 18:23   ` Sakari Ailus
2026-08-26  6:56     ` Antti Laakso
2026-08-26  7:54       ` Sakari Ailus
2026-08-21 11:42 ` [PATCH v2 41/44] media: ipu6: Set model name for ipu7 Antti Laakso
2026-08-21 11:43 ` [PATCH v2 42/44] media: ipu6: Add ipu7.5 buttress support Antti Laakso
2026-08-21 11:43 ` [PATCH v2 43/44] media: ipu6: Add ipu7.5 mmu initialization data Antti Laakso
2026-08-21 11:43 ` [PATCH v2 44/44] media: ipu6: Enable ipu7 and ipu7.5 Antti Laakso

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260821114302.365532-11-antti.laakso@linux.intel.com \
    --to=antti.laakso@linux.intel.com \
    --cc=daxing.li@intel.com \
    --cc=linux-media@vger.kernel.org \
    --cc=mchehab@kernel.org \
    --cc=ong.hock.yu@intel.com \
    --cc=sakari.ailus@linux.intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.