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Message-ID: <20221013183854.21087-4-vidyas@nvidia.com>
Date: Fri, 14 Oct 2022 00:08:36 +0530
From: Vidya Sagar <vidyas@...dia.com>
To: <lpieralisi@...nel.org>, <robh@...nel.org>, <kw@...ux.com>,
<bhelgaas@...gle.com>, <thierry.reding@...il.com>,
<jonathanh@...dia.com>, <kishon@...com>, <vkoul@...nel.org>,
<mani@...nel.org>, <Sergey.Semin@...kalelectronics.ru>,
<ffclaire1224@...il.com>
CC: <linux-pci@...r.kernel.org>, <linux-tegra@...r.kernel.org>,
<linux-kernel@...r.kernel.org>, <linux-phy@...ts.infradead.org>,
<kthota@...dia.com>, <mmaddireddy@...dia.com>, <vidyas@...dia.com>,
<sagar.tv@...il.com>
Subject: [PATCH V3 03/21] PCI: tegra194: Fix polling delay for L2 state
As per PCIe spec r6.0, sec 5.3.3.2.1, after sending PME_Turn_Off message,
Root port should wait for 1~10 msec for PME_TO_Ack message. Currently,
driver is polling for 10 msec with 1 usec delay which is aggressive.
Change it to 10 msec polling with 100 usec delay. Since this function
is used in non-atomic context only, use non-atomic poll function.
Fixes: 56e15a238d92 ("PCI: tegra: Add Tegra194 PCIe support")
Signed-off-by: Vidya Sagar <vidyas@...dia.com>
---
V3:
* Changed atomic call to non-atomic call
* Reworded the commit message
V2:
* None
drivers/pci/controller/dwc/pcie-tegra194.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index a33c86e3de9d..685aee378c93 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -207,7 +207,8 @@
#define CAP_SPCIE_CAP_OFF_USP_TX_PRESET0_MASK GENMASK(11, 8)
#define CAP_SPCIE_CAP_OFF_USP_TX_PRESET0_SHIFT 8
-#define PME_ACK_TIMEOUT 10000
+#define PME_ACK_DELAY 100 /* 100 us */
+#define PME_ACK_TIMEOUT 10000 /* 10 ms */
#define LTSSM_TIMEOUT 50000 /* 50ms */
@@ -1611,9 +1612,9 @@ static int tegra_pcie_try_link_l2(struct tegra_pcie_dw *pcie)
val |= APPL_PM_XMT_TURNOFF_STATE;
appl_writel(pcie, val, APPL_RADM_STATUS);
- return readl_poll_timeout_atomic(pcie->appl_base + APPL_DEBUG, val,
- val & APPL_DEBUG_PM_LINKST_IN_L2_LAT,
- 1, PME_ACK_TIMEOUT);
+ return readl_poll_timeout(pcie->appl_base + APPL_DEBUG, val,
+ val & APPL_DEBUG_PM_LINKST_IN_L2_LAT,
+ PME_ACK_DELAY, PME_ACK_TIMEOUT);
}
static void tegra_pcie_dw_pme_turnoff(struct tegra_pcie_dw *pcie)
--
2.17.1
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