linux-kernel - [PATCH v1 3/5] PCI: brcmstb: Replace status loops with read_poll_timeout

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Message-Id: <20221006220322.33000-4-jim2101024@gmail.com>
Date:   Thu,  6 Oct 2022 18:03:19 -0400
From:   Jim Quinlan <jim2101024@...il.com>
To:     linux-pci@...r.kernel.org,
        Nicolas Saenz Julienne <nsaenz@...nel.org>,
        Bjorn Helgaas <bhelgaas@...gle.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
        Cyril Brulebois <kibi@...ian.org>,
        bcm-kernel-feedback-list@...adcom.com, jim2101024@...il.com,
        james.quinlan@...adcom.com
Cc:     Florian Fainelli <f.fainelli@...il.com>,
        Lorenzo Pieralisi <lpieralisi@...nel.org>,
        Rob Herring <robh@...nel.org>,
        Krzysztof Wilczyński <kw@...ux.com>,
        linux-rpi-kernel@...ts.infradead.org (moderated list:BROADCOM
        BCM2711/BCM2835 ARM ARCHITECTURE),
        linux-arm-kernel@...ts.infradead.org (moderated list:BROADCOM
        BCM2711/BCM2835 ARM ARCHITECTURE),
        linux-kernel@...r.kernel.org (open list)
Subject: [PATCH v1 3/5] PCI: brcmstb: Replace status loops with read_poll_timeout_atomic()

It would be nice to replace the PCIe link-up loop as well but
there are too many uses of this that do not poll (and the
read_poll_timeout uses "timeout==0" to loop forever).

Signed-off-by: Jim Quinlan <jim2101024@...il.com>
---
 drivers/pci/controller/pcie-brcmstb.c | 27 ++++++++++-----------------
 1 file changed, 10 insertions(+), 17 deletions(-)

diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index 39b545713ba0..c7210cec1f58 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -9,6 +9,7 @@
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/ioport.h>
 #include <linux/irqchip/chained_irq.h>
 #include <linux/irqdomain.h>
@@ -302,42 +303,34 @@ static u32 brcm_pcie_mdio_form_pkt(int port, int regad, int cmd)
 /* negative return value indicates error */
 static int brcm_pcie_mdio_read(void __iomem *base, u8 port, u8 regad, u32 *val)
 {
-	int tries;
 	u32 data;
+	int err;
 
 	writel(brcm_pcie_mdio_form_pkt(port, regad, MDIO_CMD_READ),
 		   base + PCIE_RC_DL_MDIO_ADDR);
 	readl(base + PCIE_RC_DL_MDIO_ADDR);
-
-	data = readl(base + PCIE_RC_DL_MDIO_RD_DATA);
-	for (tries = 0; !MDIO_RD_DONE(data) && tries < 10; tries++) {
-		udelay(10);
-		data = readl(base + PCIE_RC_DL_MDIO_RD_DATA);
-	}
-
+	err = readl_poll_timeout_atomic(base + PCIE_RC_DL_MDIO_RD_DATA, data,
+					MDIO_RD_DONE(data), 10, 100);
 	*val = FIELD_GET(MDIO_DATA_MASK, data);
-	return MDIO_RD_DONE(data) ? 0 : -EIO;
+
+	return err;
 }
 
 /* negative return value indicates error */
 static int brcm_pcie_mdio_write(void __iomem *base, u8 port,
 				u8 regad, u16 wrdata)
 {
-	int tries;
 	u32 data;
+	int err;
 
 	writel(brcm_pcie_mdio_form_pkt(port, regad, MDIO_CMD_WRITE),
 		   base + PCIE_RC_DL_MDIO_ADDR);
 	readl(base + PCIE_RC_DL_MDIO_ADDR);
 	writel(MDIO_DATA_DONE_MASK | wrdata, base + PCIE_RC_DL_MDIO_WR_DATA);
 
-	data = readl(base + PCIE_RC_DL_MDIO_WR_DATA);
-	for (tries = 0; !MDIO_WT_DONE(data) && tries < 10; tries++) {
-		udelay(10);
-		data = readl(base + PCIE_RC_DL_MDIO_WR_DATA);
-	}
-
-	return MDIO_WT_DONE(data) ? 0 : -EIO;
+	err = readw_poll_timeout_atomic(base + PCIE_RC_DL_MDIO_WR_DATA, data,
+					MDIO_WT_DONE(data), 10, 100);
+	return err;
 }
 
 /*
-- 
2.17.1