From: Hongxing Zhu <hongxing.zhu@nxp.com>
To: Lucas Stach <l.stach@pengutronix.de>,
"bhelgaas@google.com" <bhelgaas@google.com>,
"robh+dt@kernel.org" <robh+dt@kernel.org>,
"broonie@kernel.org" <broonie@kernel.org>,
"lorenzo.pieralisi@arm.com" <lorenzo.pieralisi@arm.com>,
"festevam@gmail.com" <festevam@gmail.com>,
"francesco.dolcini@toradex.com" <francesco.dolcini@toradex.com>
Cc: "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"kernel@pengutronix.de" <kernel@pengutronix.de>,
dl-linux-imx <linux-imx@nxp.com>
Subject: RE: [PATCH v14 13/17] PCI: imx6: Reduce resume time by only starting link if it was up before suspend
Date: Wed, 13 Jul 2022 10:57:23 +0000 [thread overview]
Message-ID: <AS8PR04MB86760B1E09E3CD01C7DC19B68C899@AS8PR04MB8676.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <26d5e056c4b4779293b79012468f2ac821f4c06c.camel@pengutronix.de>
> -----Original Message-----
> From: Lucas Stach <l.stach@pengutronix.de>
> Sent: 2022年7月13日 16:48
> To: Hongxing Zhu <hongxing.zhu@nxp.com>; bhelgaas@google.com;
> robh+dt@kernel.org; broonie@kernel.org; lorenzo.pieralisi@arm.com;
> festevam@gmail.com; francesco.dolcini@toradex.com
> Cc: linux-pci@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> linux-kernel@vger.kernel.org; kernel@pengutronix.de; dl-linux-imx
> <linux-imx@nxp.com>
> Subject: Re: [PATCH v14 13/17] PCI: imx6: Reduce resume time by only starting
> link if it was up before suspend
>
> Am Freitag, dem 01.07.2022 um 11:25 +0800 schrieb Richard Zhu:
> > Because i.MX PCIe doesn't support hot-plug feature. In the link down
> > scenario, only start the PCIe link training in resume when the link is
> > up before system suspend to avoid the long latency in the link
> > training period.
> >
> > Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> > Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> > ---
> > drivers/pci/controller/dwc/pci-imx6.c | 8 +++++---
> > 1 file changed, 5 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pci-imx6.c
> > b/drivers/pci/controller/dwc/pci-imx6.c
> > index e236f824c808..5a06fbca82d6 100644
> > --- a/drivers/pci/controller/dwc/pci-imx6.c
> > +++ b/drivers/pci/controller/dwc/pci-imx6.c
> > @@ -67,6 +67,7 @@ struct imx6_pcie {
> > struct dw_pcie *pci;
> > int reset_gpio;
> > bool gpio_active_high;
> > + bool link_is_up;
> > struct clk *pcie_bus;
> > struct clk *pcie_phy;
> > struct clk *pcie_inbound_axi;
> > @@ -881,11 +882,13 @@ static int imx6_pcie_start_link(struct dw_pcie
> *pci)
> > dev_info(dev, "Link: Gen2 disabled\n");
> > }
> >
> > + imx6_pcie->link_is_up = true;
> > tmp = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA);
> > dev_info(dev, "Link up, Gen%i\n", tmp & PCI_EXP_LNKSTA_CLS);
> > return 0;
> >
> > err_reset_phy:
> > + imx6_pcie->link_is_up = false;
> > dev_dbg(dev, "PHY DEBUG_R0=0x%08x DEBUG_R1=0x%08x\n",
> > dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG0),
> > dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG1)); @@ -1032,9 +1035,8
> @@
> > static int imx6_pcie_resume_noirq(struct device *dev)
> > return ret;
> > dw_pcie_setup_rc(pp);
> >
> > - ret = imx6_pcie_start_link(imx6_pcie->pci);
> > - if (ret < 0)
> > - dev_info(dev, "pcie link is down after resume.\n");
> > + if (imx6_pcie->link_is_up)
> > + imx6_pcie_start_link(imx6_pcie->pci);
>
> While the change itself is correct, the removal of the return value check should
> be added to the previous patch, as that's the point where you change this
> function to always return 0, rendering this check pointless.
Thanks for your comments.
Yes, it is. Indeed the return check should be cleaned up in the 12/17, since
imx6_pcie_start_link() always returns 0.
Best Regards
Richard Zhu
>
> Regards,
> Lucas
>
> >
> > return 0;
> > }
>
next prev parent reply other threads:[~2022-07-13 10:57 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-01 3:25 [PATCH v14 0/17] PCI: imx6: refine codes and add the error propagation Richard Zhu
2022-07-01 3:25 ` [PATCH v14 01/17] PCI: imx6: Move imx6_pcie_grp_offset(), imx6_pcie_configure_type() earlier Richard Zhu
2022-07-13 8:13 ` Lucas Stach
2022-07-01 3:25 ` [PATCH v14 02/17] PCI: imx6: Move PHY management functions together Richard Zhu
2022-07-13 8:15 ` Lucas Stach
2022-07-01 3:25 ` [PATCH v14 03/17] PCI: imx6: Move imx6_pcie_enable_ref_clk() earlier Richard Zhu
2022-07-13 8:16 ` Lucas Stach
2022-07-01 3:25 ` [PATCH v14 04/17] PCI: imx6: Move imx6_pcie_clk_disable() earlier Richard Zhu
2022-07-01 3:25 ` [PATCH v14 05/17] PCI: imx6: Factor out ref clock disable to match enable Richard Zhu
2022-07-13 8:17 ` Lucas Stach
2022-07-01 3:25 ` [PATCH v14 06/17] PCI: imx6: Collect clock enables in imx6_pcie_clk_enable() Richard Zhu
2022-07-01 3:25 ` [PATCH v14 07/17] PCI: imx6: Propagate .host_init() errors to caller Richard Zhu
2022-07-01 3:25 ` [PATCH v14 08/17] PCI: imx6: Disable i.MX6QDL clock when disabling ref clocks Richard Zhu
2022-07-01 3:25 ` [PATCH v14 09/17] PCI: imx6: Call host init function directly in resume Richard Zhu
2022-07-13 8:26 ` Lucas Stach
2022-07-01 3:25 ` [PATCH v14 10/17] PCI: imx6: Turn off regulator when system is in suspend mode Richard Zhu
2022-07-13 8:34 ` Lucas Stach
2022-07-13 10:56 ` Hongxing Zhu
2022-07-13 11:22 ` Lucas Stach
2022-07-13 12:55 ` Hongxing Zhu
2022-07-01 3:25 ` [PATCH v14 11/17] PCI: imx6: Move regulator enable out of imx6_pcie_deassert_core_reset() Richard Zhu
2022-07-13 8:41 ` Lucas Stach
2022-07-13 10:57 ` Hongxing Zhu
2022-07-01 3:25 ` [PATCH v14 12/17] PCI: imx6: Mark the link down as non-fatal error Richard Zhu
2022-07-13 8:44 ` Lucas Stach
2022-07-01 3:25 ` [PATCH v14 13/17] PCI: imx6: Reduce resume time by only starting link if it was up before suspend Richard Zhu
2022-07-13 8:47 ` Lucas Stach
2022-07-13 10:57 ` Hongxing Zhu [this message]
2022-07-01 3:25 ` [PATCH v14 14/17] PCI: imx6: Do not hide phy driver callbacks and refine the error handling Richard Zhu
2022-07-13 8:58 ` Lucas Stach
2022-07-13 10:57 ` Hongxing Zhu
2022-07-13 11:17 ` Lucas Stach
2022-07-13 12:52 ` Hongxing Zhu
2022-07-01 3:25 ` [PATCH v14 15/17] PCI: imx6: Disable clocks in reverse order of enable Richard Zhu
2022-07-13 8:59 ` Lucas Stach
2022-07-01 3:25 ` [PATCH v14 16/17] PCI: imx6: Move the imx6_pcie_ltssm_disable() earlier Richard Zhu
2022-07-13 9:04 ` Lucas Stach
2022-07-13 11:00 ` Hongxing Zhu
2022-07-01 3:25 ` [PATCH v14 17/17] PCI: imx6: Reformat suspend callback to keep symmetric with resume Richard Zhu
2022-07-13 9:07 ` Lucas Stach
2022-07-11 22:29 ` [PATCH v14 0/17] PCI: imx6: refine codes and add the error propagation Bjorn Helgaas
2022-07-13 16:45 ` Bjorn Helgaas
2022-07-14 4:15 ` Hongxing Zhu
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