Linux PCI subsystem development
 help / color / mirror / Atom feed
From: Frank Li <Frank.Li@nxp.com>
To: s-vadapalli@ti.com
Cc: Frank.Li@nxp.com, bhelgaas@google.com, conor+dt@kernel.org,
	devicetree@vger.kernel.org, krzk+dt@kernel.org, kw@linux.com,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org,
	linux-pci@vger.kernel.org, lpieralisi@kernel.org,
	manivannan.sadhasivam@linaro.org, robh@kernel.org,
	tony@atomide.com, vigneshr@ti.com
Subject: [PATCH v2 1/1] Revert "ARM: dts: Update pcie ranges for dra7"
Date: Fri, 11 Apr 2025 11:34:54 -0400	[thread overview]
Message-ID: <20250411153454.3258098-1-Frank.Li@nxp.com> (raw)

This reverts commit c761028ef5e27f477fe14d2b134164c584fc21ee.

The commit being reverted updated the "ranges" property for the sake of
readability. However, this change is no longer appropriate due to the
following reasons:

- On many SoCs, the PCIe parent bus translates CPU addresses to different
values before passing them to the PCIe controller.
- The reverted commit introduced a fake address translation, which violates
the fundamental DTS principle: the device tree should reflect actual
hardware behavior.

Reverting this change prepares for the cleanup of the driver's
cpu_addr_fixup() hook.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
Change from v1 to v2:
- update commit message to add more detail.

Previous disscusion at
https://lore.kernel.org/linux-pci/20250314064642.fyf3jqylmc6meft7@uda0492258/
---
 arch/arm/boot/dts/ti/omap/dra7.dtsi | 29 +++++++++++------------------
 1 file changed, 11 insertions(+), 18 deletions(-)

diff --git a/arch/arm/boot/dts/ti/omap/dra7.dtsi b/arch/arm/boot/dts/ti/omap/dra7.dtsi
index b709703f6c0d4..711ce4c31bb1f 100644
--- a/arch/arm/boot/dts/ti/omap/dra7.dtsi
+++ b/arch/arm/boot/dts/ti/omap/dra7.dtsi
@@ -195,24 +195,22 @@ axi0: target-module@51000000 {
 			clock-names = "fck", "phy-clk", "phy-clk-div";
 			#size-cells = <1>;
 			#address-cells = <1>;
-			ranges = <0x51000000 0x51000000 0x3000>,
-				 <0x20000000 0x20000000 0x10000000>;
+			ranges = <0x51000000 0x51000000 0x3000
+				  0x0	     0x20000000 0x10000000>;
 			dma-ranges;
 			/**
 			 * To enable PCI endpoint mode, disable the pcie1_rc
 			 * node and enable pcie1_ep mode.
 			 */
 			pcie1_rc: pcie@51000000 {
-				reg = <0x51000000 0x2000>,
-				      <0x51002000 0x14c>,
-				      <0x20001000 0x2000>;
+				reg = <0x51000000 0x2000>, <0x51002000 0x14c>, <0x1000 0x2000>;
 				reg-names = "rc_dbics", "ti_conf", "config";
 				interrupts = <0 232 0x4>, <0 233 0x4>;
 				#address-cells = <3>;
 				#size-cells = <2>;
 				device_type = "pci";
-				ranges = <0x81000000 0 0x00000000 0x20003000 0 0x00010000>,
-					 <0x82000000 0 0x20013000 0x20013000 0 0x0ffed000>;
+				ranges = <0x81000000 0 0          0x03000 0 0x00010000
+					  0x82000000 0 0x20013000 0x13000 0 0xffed000>;
 				bus-range = <0x00 0xff>;
 				#interrupt-cells = <1>;
 				num-lanes = <1>;
@@ -235,10 +233,7 @@ pcie1_intc: interrupt-controller {
 			};
 
 			pcie1_ep: pcie_ep@51000000 {
-				reg = <0x51000000 0x28>,
-				      <0x51002000 0x14c>,
-				      <0x51001000 0x28>,
-				      <0x20001000 0x10000000>;
+				reg = <0x51000000 0x28>, <0x51002000 0x14c>, <0x51001000 0x28>, <0x1000 0x10000000>;
 				reg-names = "ep_dbics", "ti_conf", "ep_dbics2", "addr_space";
 				interrupts = <0 232 0x4>;
 				num-lanes = <1>;
@@ -269,21 +264,19 @@ axi1: target-module@51800000 {
 			reset-names = "rstctrl";
 			#size-cells = <1>;
 			#address-cells = <1>;
-			ranges = <0x51800000 0x51800000 0x3000>,
-				 <0x30000000 0x30000000 0x10000000>;
+			ranges = <0x51800000 0x51800000 0x3000
+				  0x0	     0x30000000 0x10000000>;
 			dma-ranges;
 			status = "disabled";
 			pcie2_rc: pcie@51800000 {
-				reg = <0x51800000 0x2000>,
-				      <0x51802000 0x14c>,
-				      <0x30001000 0x2000>;
+				reg = <0x51800000 0x2000>, <0x51802000 0x14c>, <0x1000 0x2000>;
 				reg-names = "rc_dbics", "ti_conf", "config";
 				interrupts = <0 355 0x4>, <0 356 0x4>;
 				#address-cells = <3>;
 				#size-cells = <2>;
 				device_type = "pci";
-				ranges = <0x81000000 0 0x00000000 0x30003000 0 0x00010000>,
-					 <0x82000000 0 0x30013000 0x30013000 0 0x0ffed000>;
+				ranges = <0x81000000 0 0          0x03000 0 0x00010000
+					  0x82000000 0 0x30013000 0x13000 0 0xffed000>;
 				bus-range = <0x00 0xff>;
 				#interrupt-cells = <1>;
 				num-lanes = <1>;
-- 
2.34.1


             reply	other threads:[~2025-04-11 15:35 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-04-11 15:34 Frank Li [this message]
2025-05-22 19:29 ` [PATCH v2 1/1] Revert "ARM: dts: Update pcie ranges for dra7" Frank Li
2025-05-23  5:32   ` Siddharth Vadapalli
2025-05-23 18:53     ` Frank Li
2025-05-29 17:11 ` Kevin Hilman

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=20250411153454.3258098-1-Frank.Li@nxp.com \
    --to=frank.li@nxp.com \
    --cc=bhelgaas@google.com \
    --cc=conor+dt@kernel.org \
    --cc=devicetree@vger.kernel.org \
    --cc=krzk+dt@kernel.org \
    --cc=kw@linux.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-omap@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=lpieralisi@kernel.org \
    --cc=manivannan.sadhasivam@linaro.org \
    --cc=robh@kernel.org \
    --cc=s-vadapalli@ti.com \
    --cc=tony@atomide.com \
    --cc=vigneshr@ti.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox