> -----Original Message----- > From: Tim Harvey <tharvey@xxxxxxxxxxxxx> > Sent: 2025年6月13日 3:48 > To: Frank Li <frank.li@xxxxxxx> > Cc: Hongxing Zhu <hongxing.zhu@xxxxxxx>; l.stach@xxxxxxxxxxxxxx; > lpieralisi@xxxxxxxxxx; kw@xxxxxxxxx; manivannan.sadhasivam@xxxxxxxxxx; > robh@xxxxxxxxxx; bhelgaas@xxxxxxxxxx; shawnguo@xxxxxxxxxx; > s.hauer@xxxxxxxxxxxxxx; kernel@xxxxxxxxxxxxxx; festevam@xxxxxxxxx; > linux-pci@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > imx@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v2 1/2] PCI: imx6: Remove apps_reset toggle in _core_reset > functions > > On Thu, Jun 12, 2025 at 9:11 AM Frank Li <Frank.li@xxxxxxx> wrote: > > > > On Thu, Jun 12, 2025 at 10:27:46AM +0800, Richard Zhu wrote: > > > apps_reset is LTSSM_EN on i.MX7, i.MX8MQ, i.MX8MM and i.MX8MP > platforms. > > > Since the assertion/de-assertion of apps_reset(LTSSM_EN bit) had > > > been wrappered in imx_pcie_ltssm_enable() and > > > imx_pcie_ltssm_disable(); > > > > > > Remove apps_reset toggle in imx_pcie_assert_core_reset() and > > > imx_pcie_deassert_core_reset() functions. Use > > > imx_pcie_ltssm_enable() and imx_pcie_ltssm_disable() to configure > apps_reset directly. > > > > > > Fix fail to enumerate reliably PI7C9X2G608GP (hotplug) at i.MX8MM, > > > which reported By Tim. > > > > > > > You may rename apps_reset to ltssm_reset to avoid confuse for legancy > > platform later. > > Hi Frank and Richard, > > I was thinking of making the same suggestion however the apps reset is in > several places: > - imx8m*.dtsi pci node as 'reset-names' and reset index number #define > - imx8m*-reset.h bindings as reset index number/define > - pci-imx.c driver > > Granted it is used by imx7d.dtsi, fsl,imx8mq-pcie, fsl,imx8mm-pcie, > fsl,imx8mp-pcie and in every one of those reference manuals it's bit6 of > SRC_PCIEPH_RCR named PCIE_CTRL_APPS_EN but described as > 'Pcie_ctrl_app_ltssm_enable'. Can you ask your references to get more > definition for this bit? I'm still unclear why 'de-asserting' it twice was an issue. I suspect that the link had been abnormal already before 'de-asserting' the ltssm_en bit at twice time. The regmap_read() trigger the hang in your use case actually. Best Regards Richard Zhu > > Regardless, any cleanup changing the name can be a seperate patch in my > opinion. > > Best Regards, > > Tim > > > > > > Reviewed-by: Frank Li <Frank.Li@xxxxxxx> > > > > > > > Reported-by: Tim Harvey <tharvey@xxxxxxxxxxxxx> > > > Closes: > > > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flo > > > > re.kernel.org%2Fall%2FCAJ%2BvNU3ohR2YKTwC4xoYrc1z-neDoH2TTZcMHDy% > 2Bp > > > > oj9%3DjSy%2Bw%40mail.gmail.com%2F&data=05%7C02%7Chongxing.zhu%40 > nxp. > > > > com%7C3d1b3ffa38ef4038063a08dda9ea0c63%7C686ea1d3bc2b4c6fa92cd99c > 5c3 > > > > 01635%7C0%7C0%7C638853544881671954%7CUnknown%7CTWFpbGZsb3d8e > yJFbXB0e > > > > U1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsI > > > > ldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=7vV5HyEaluYf4i4l2anEX%2Fb6z3x > UPc0 > > > urhHNIdTPKwU%3D&reserved=0 > > > Fixes: ef61c7d8d032 ("PCI: imx6: Deassert apps_reset in > > > imx_pcie_deassert_core_reset()") > > > Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx> > > > --- > > > drivers/pci/controller/dwc/pci-imx6.c | 5 +++-- > > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c > > > b/drivers/pci/controller/dwc/pci-imx6.c > > > index 5f267dd261b5..f4e0342f4d56 100644 > > > --- a/drivers/pci/controller/dwc/pci-imx6.c > > > +++ b/drivers/pci/controller/dwc/pci-imx6.c > > > @@ -776,7 +776,6 @@ static int imx7d_pcie_core_reset(struct imx_pcie > > > *imx_pcie, bool assert) static void > > > imx_pcie_assert_core_reset(struct imx_pcie *imx_pcie) { > > > reset_control_assert(imx_pcie->pciephy_reset); > > > - reset_control_assert(imx_pcie->apps_reset); > > > > > > if (imx_pcie->drvdata->core_reset) > > > imx_pcie->drvdata->core_reset(imx_pcie, true); @@ > > > -788,7 +787,6 @@ static void imx_pcie_assert_core_reset(struct > > > imx_pcie *imx_pcie) static int imx_pcie_deassert_core_reset(struct > > > imx_pcie *imx_pcie) { > > > reset_control_deassert(imx_pcie->pciephy_reset); > > > - reset_control_deassert(imx_pcie->apps_reset); > > > > > > if (imx_pcie->drvdata->core_reset) > > > imx_pcie->drvdata->core_reset(imx_pcie, false); @@ > > > -1176,6 +1174,9 @@ static int imx_pcie_host_init(struct dw_pcie_rp *pp) > > > } > > > } > > > > > > + /* Make sure that PCIe LTSSM is cleared */ > > > + imx_pcie_ltssm_disable(dev); > > > + > > > ret = imx_pcie_deassert_core_reset(imx_pcie); > > > if (ret < 0) { > > > dev_err(dev, "pcie deassert core reset failed: %d\n", > > > ret); > > > -- > > > 2.37.1 > > >
