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From: Anand Moon <linux.amoon@gmail.com>
To: "Lorenzo Pieralisi" <lpieralisi@kernel.org>,
	"Krzysztof Wilczyński" <kwilczynski@kernel.org>,
	"Manivannan Sadhasivam" <mani@kernel.org>,
	"Rob Herring" <robh@kernel.org>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	"Thierry Reding" <thierry.reding@gmail.com>,
	"Jonathan Hunter" <jonathanh@nvidia.com>,
	linux-pci@vger.kernel.org (open list:PCI NATIVE HOST BRIDGE AND
	ENDPOINT DRIVERS),
	devicetree@vger.kernel.org (open list:OPEN FIRMWARE AND
	FLATTENED DEVICE TREE BINDINGS),
	linux-tegra@vger.kernel.org (open list:TEGRA ARCHITECTURE
	SUPPORT), linux-kernel@vger.kernel.org (open list)
Cc: Anand Moon <linux.amoon@gmail.com>,
	Mikko Perttunen <mperttunen@nvidia.com>
Subject: [PATCH v1 3/5] PCI: tegra: Use readl_poll_timeout() for link status polling
Date: Fri, 26 Sep 2025 12:57:44 +0530	[thread overview]
Message-ID: <20250926072905.126737-4-linux.amoon@gmail.com> (raw)
In-Reply-To: <20250926072905.126737-1-linux.amoon@gmail.com>

Replace the manual `do-while` polling loops with the readl_poll_timeout()
helper when checking the link DL_UP and DL_LINK_ACTIVE status bits
during link bring-up. This simplifies the code by removing the open-coded
timeout logic in favor of the standard, more robust iopoll framework.
The change improves readability and reduces code duplication.

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Anand Moon <linux.amoon@gmail.com>
---
v1: dropped the include  <linux/iopoll.h> header file.
---
 drivers/pci/controller/pci-tegra.c | 37 +++++++++++-------------------
 1 file changed, 14 insertions(+), 23 deletions(-)

diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c
index 07a61d902eae..b0056818a203 100644
--- a/drivers/pci/controller/pci-tegra.c
+++ b/drivers/pci/controller/pci-tegra.c
@@ -2169,37 +2169,28 @@ static bool tegra_pcie_port_check_link(struct tegra_pcie_port *port)
 	value |= RP_PRIV_MISC_PRSNT_MAP_EP_PRSNT;
 	writel(value, port->base + RP_PRIV_MISC);
 
-	do {
-		unsigned int timeout = TEGRA_PCIE_LINKUP_TIMEOUT;
+	while (retries--) {
+		int err;
 
-		do {
-			value = readl(port->base + RP_VEND_XP);
-
-			if (value & RP_VEND_XP_DL_UP)
-				break;
-
-			usleep_range(1000, 2000);
-		} while (--timeout);
-
-		if (!timeout) {
+		err = readl_poll_timeout(port->base + RP_VEND_XP, value,
+					 value & RP_VEND_XP_DL_UP,
+					 1000,
+					 TEGRA_PCIE_LINKUP_TIMEOUT * 1000);
+		if (err) {
 			dev_dbg(dev, "link %u down, retrying\n", port->index);
 			goto retry;
 		}
 
-		timeout = TEGRA_PCIE_LINKUP_TIMEOUT;
-
-		do {
-			value = readl(port->base + RP_LINK_CONTROL_STATUS);
-
-			if (value & RP_LINK_CONTROL_STATUS_DL_LINK_ACTIVE)
-				return true;
-
-			usleep_range(1000, 2000);
-		} while (--timeout);
+		err = readl_poll_timeout(port->base + RP_LINK_CONTROL_STATUS,
+					 value,
+					 value & RP_LINK_CONTROL_STATUS_DL_LINK_ACTIVE,
+					 1000, TEGRA_PCIE_LINKUP_TIMEOUT * 1000);
+		if (!err)
+			return true;
 
 retry:
 		tegra_pcie_port_reset(port);
-	} while (--retries);
+	}
 
 	return false;
 }
-- 
2.50.1


  parent reply	other threads:[~2025-09-26  7:30 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-09-26  7:27 [PATCH v1 0/5] PCI: tegra: A couple of cleanups Anand Moon
2025-09-26  7:27 ` [PATCH v1 1/5] dt-bindings: PCI: Convert the existing nvidia,tegra-pcie.txt bindings documentation into a YAML schema Anand Moon
2025-09-26 13:56   ` Rob Herring
2025-09-29  7:39     ` Anand Moon
2025-09-29 13:48       ` Rob Herring
2025-09-29 15:25         ` Anand Moon
2025-09-30 14:37           ` Rob Herring
2025-09-30 16:32             ` Anand Moon
2025-10-01 15:33               ` Rob Herring
2025-10-01 18:57                 ` Anand Moon
2025-09-26  7:27 ` [PATCH v1 2/5] PCI: tegra: Simplify clock handling by using clk_bulk*() functions Anand Moon
2025-09-26 18:12   ` Frank Li
2025-09-27  5:50     ` Anand Moon
2025-09-29 14:01       ` Manivannan Sadhasivam
2025-09-29 16:12         ` Anand Moon
2025-09-26  7:27 ` Anand Moon [this message]
2025-10-19  7:50   ` [PATCH v1 3/5] PCI: tegra: Use readl_poll_timeout() for link status polling Manivannan Sadhasivam
2025-10-20 12:17     ` Anand Moon
2025-10-21  1:43       ` Manivannan Sadhasivam
2025-10-24  6:17         ` Anand Moon
2025-09-26  7:27 ` [PATCH v1 4/5] PCI: tegra: Use BIT() and GENMASK() macros for register definitions Anand Moon
2025-09-26  7:27 ` [PATCH v1 5/5] PCI: tegra: Document map_lock and mask_lock usage Anand Moon

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