linux-kernel - [PATCH v2 5/7] PCI: rcar: Replace msleep(5) with usleep

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250822155908.625553-6-18255117159@163.com>
Date: Fri, 22 Aug 2025 23:59:06 +0800
From: Hans Zhang <18255117159@....com>
To: bhelgaas@...gle.com,
	helgaas@...nel.org,
	linux-pci@...r.kernel.org,
	linux-kernel@...r.kernel.org
Cc: Hans Zhang <18255117159@....com>
Subject: [PATCH v2 5/7] PCI: rcar: Replace msleep(5) with usleep_range() for precise PHY ready checking

The msleep(5) in rcar_pcie_wait_for_phyrdy() may sleep longer than
intended due to timer granularity, which can cause unnecessary delays
in PHY ready detection. Replace it with usleep_range() for a more precise
delay of approximately 5ms.

Signed-off-by: Hans Zhang <18255117159@....com>
---
 drivers/pci/controller/pcie-rcar.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c
index 7583699ef7b6..8d0f5a4a7fc0 100644
--- a/drivers/pci/controller/pcie-rcar.c
+++ b/drivers/pci/controller/pcie-rcar.c
@@ -11,6 +11,8 @@
 
 #include "pcie-rcar.h"
 
+#define PCIE_PHYRDY_CHECK_US	5000
+
 void rcar_pci_write_reg(struct rcar_pcie *pcie, u32 val, unsigned int reg)
 {
 	writel(val, pcie->base + reg);
@@ -39,7 +41,7 @@ int rcar_pcie_wait_for_phyrdy(struct rcar_pcie *pcie)
 		if (rcar_pci_read_reg(pcie, PCIEPHYSR) & PHYRDY)
 			return 0;
 
-		msleep(5);
+		usleep_range(PCIE_PHYRDY_CHECK_US, PCIE_PHYRDY_CHECK_US + 100);
 	}
 
 	return -ETIMEDOUT;
-- 
2.25.1