From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from foss.arm.com ([217.140.101.70]:34864 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727094AbeH1OBF (ORCPT ); Tue, 28 Aug 2018 10:01:05 -0400 Date: Tue, 28 Aug 2018 11:10:07 +0100 From: Lorenzo Pieralisi To: Jisheng Zhang Cc: Jingoo Han , Joao Pinto , Bjorn Helgaas , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2] PCI: dwc: fix scheduling while atomic issues Message-ID: <20180828101007.GB27217@e107981-ln.cambridge.arm.com> References: <20180821141512.368e3df2@xhacker.debian> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20180821141512.368e3df2@xhacker.debian> Sender: linux-pci-owner@vger.kernel.org List-ID: On Tue, Aug 21, 2018 at 02:15:12PM +0800, Jisheng Zhang wrote: > When programming inbound/outbound atu, we call usleep_range() after > each checking PCIE_ATU_ENABLE bit. Unfortunately, the atu programming > can be called in atomic context: > > inbound atu programming could be called through > pci_epc_write_header() > =>dw_pcie_ep_write_header() > =>dw_pcie_prog_inbound_atu() > > outbound atu programming could be called through > pci_bus_read_config_dword() > =>dw_pcie_rd_conf() > =>dw_pcie_prog_outbound_atu() > > Fix this issue by calling mdelay() instead. > > Signed-off-by: Jisheng Zhang Mind adding a Fixes: tag please ? Is: commit f8aed6ec624f ("PCI: dwc: designware: Add EP mode support") the commit you are fixing ? Thanks, Lorenzo > --- > > Since v1 > - use mdelay() instead of udelay() to avoid __bad_udelay() > > drivers/pci/controller/dwc/pcie-designware.c | 8 ++++---- > drivers/pci/controller/dwc/pcie-designware.h | 3 +-- > 2 files changed, 5 insertions(+), 6 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c > index 778c4f76a884..2153956a0b20 100644 > --- a/drivers/pci/controller/dwc/pcie-designware.c > +++ b/drivers/pci/controller/dwc/pcie-designware.c > @@ -135,7 +135,7 @@ static void dw_pcie_prog_outbound_atu_unroll(struct dw_pcie *pci, int index, > if (val & PCIE_ATU_ENABLE) > return; > > - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX); > + mdelay(LINK_WAIT_IATU); > } > dev_err(pci->dev, "Outbound iATU is not being enabled\n"); > } > @@ -178,7 +178,7 @@ void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index, int type, > if (val & PCIE_ATU_ENABLE) > return; > > - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX); > + mdelay(LINK_WAIT_IATU); > } > dev_err(pci->dev, "Outbound iATU is not being enabled\n"); > } > @@ -236,7 +236,7 @@ static int dw_pcie_prog_inbound_atu_unroll(struct dw_pcie *pci, int index, > if (val & PCIE_ATU_ENABLE) > return 0; > > - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX); > + mdelay(LINK_WAIT_IATU); > } > dev_err(pci->dev, "Inbound iATU is not being enabled\n"); > > @@ -282,7 +282,7 @@ int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int index, int bar, > if (val & PCIE_ATU_ENABLE) > return 0; > > - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX); > + mdelay(LINK_WAIT_IATU); > } > dev_err(pci->dev, "Inbound iATU is not being enabled\n"); > > diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h > index 96126fd8403c..9f1a5e399b70 100644 > --- a/drivers/pci/controller/dwc/pcie-designware.h > +++ b/drivers/pci/controller/dwc/pcie-designware.h > @@ -26,8 +26,7 @@ > > /* Parameters for the waiting for iATU enabled routine */ > #define LINK_WAIT_MAX_IATU_RETRIES 5 > -#define LINK_WAIT_IATU_MIN 9000 > -#define LINK_WAIT_IATU_MAX 10000 > +#define LINK_WAIT_IATU 9 > > /* Synopsys-specific PCIe configuration registers */ > #define PCIE_PORT_LINK_CONTROL 0x710 > -- > 2.18.0 >