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AJvYcCX8KDXDArF+q3grdiJ5xz4V0RGKSCHplQef3lHKisvNyKxsyaUWZFF/4KZ7QUqfgbEqx9RBgvnp1rw=@vger.kernel.org X-Gm-Message-State: AOJu0YxalS2C12MYLql3k1HAeQnWJicDhqj5QrYnAiKj/kdKkwevgTCy eoAynspLw1ejn7aHnwEoxm121mpunWkYcdVA5Ri26dYNaKZCePehjtgShyosDA== X-Google-Smtp-Source: AGHT+IGIbW1tQeXnBuOqrUpxgNtqWmpwlGGiTVcd4WBp0pbssH/vd69ZwPhiHwTkU1GfRxG6/U7bqg== X-Received: by 2002:a05:6830:700a:b0:716:ab1b:6473 with SMTP id 46e09a7af769-71a77a24391mr3208834a34.30.1731678332904; Fri, 15 Nov 2024 05:45:32 -0800 (PST) Received: from thinkpad ([117.193.215.93]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-7f8c1c2c505sm1268434a12.18.2024.11.15.05.45.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 15 Nov 2024 05:45:32 -0800 (PST) Date: Fri, 15 Nov 2024 19:15:24 +0530 From: Manivannan Sadhasivam To: Krishna chaitanya chundru Cc: Jingoo Han , Lorenzo Pieralisi , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Rob Herring , Bjorn Helgaas , Konrad Dybcio , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , quic_vbadigan@quicinc.com, quic_mrana@quicinc.com, andersson@kernel.org Subject: Re: [PATCH v4 1/3] PCI: dwc: Skip waiting for link up if vendor drivers can detect Link up event Message-ID: <20241115134524.xbjgrutbpp7ehjsn@thinkpad> References: <20241115-remove_wait1-v4-0-7e3412756e3d@quicinc.com> <20241115-remove_wait1-v4-1-7e3412756e3d@quicinc.com> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20241115-remove_wait1-v4-1-7e3412756e3d@quicinc.com> On Fri, Nov 15, 2024 at 04:00:21PM +0530, Krishna chaitanya chundru wrote: > If the vendor drivers can detect the Link up event using mechanisms > such as Link up IRQ and can the driver can enumerate downstream devices "if the driver can..." > instead of waiting here, then waiting for Link up during probe is not > needed here, which optimizes the boot time. > > So skip waiting for link to be up if the driver supports 'linkup_irq'. > s/linkup_irq/use_linkup_irq > Signed-off-by: Krishna chaitanya chundru With above, Reviewed-by: Manivannan Sadhasivam - Mani > --- > drivers/pci/controller/dwc/pcie-designware-host.c | 10 ++++++++-- > drivers/pci/controller/dwc/pcie-designware.h | 1 + > 2 files changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c > index 3e41865c7290..c8208a6c03d1 100644 > --- a/drivers/pci/controller/dwc/pcie-designware-host.c > +++ b/drivers/pci/controller/dwc/pcie-designware-host.c > @@ -530,8 +530,14 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp) > goto err_remove_edma; > } > > - /* Ignore errors, the link may come up later */ > - dw_pcie_wait_for_link(pci); > + /* > + * Note: The link up delay is skipped only when a link up IRQ is present. > + * This flag should not be used to bypass the link up delay for arbitrary > + * reasons. > + */ > + if (!pp->use_linkup_irq) > + /* Ignore errors, the link may come up later */ > + dw_pcie_wait_for_link(pci); > > bridge->sysdata = pp; > > diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h > index 347ab74ac35a..1d0ec47e1986 100644 > --- a/drivers/pci/controller/dwc/pcie-designware.h > +++ b/drivers/pci/controller/dwc/pcie-designware.h > @@ -379,6 +379,7 @@ struct dw_pcie_rp { > bool use_atu_msg; > int msg_atu_index; > struct resource *msg_res; > + bool use_linkup_irq; > }; > > struct dw_pcie_ep_ops { > > -- > 2.34.1 > -- மணிவண்ணன் சதாசிவம்