From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Date: Mon, 16 Jan 2017 11:44:22 +0000 From: Jason Cooper To: Lucas Stach Subject: Re: [PATCH] PCI: mvebu: change delay after reset to the PCIe spec mandated 100ms Message-ID: <20170116114422.GA25924@io.lakedaemon.net> References: <20170116111142.6866-1-l.stach@pengutronix.de> MIME-Version: 1.0 In-Reply-To: <20170116111142.6866-1-l.stach@pengutronix.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Thomas Petazzoni , linux-pci@vger.kernel.org, patchwork-lst@pengutronix.de, kernel@pengutronix.de, Bjorn Helgaas , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+bjorn=helgaas.com@lists.infradead.org List-ID: Hi Lucas, On Mon, Jan 16, 2017 at 12:11:42PM +0100, Lucas Stach wrote: > The current default of 20ms cause some devices, which are slow to initialize, > to not show up during the bus scanning. Change this to the PCIe spec mandated > 100ms and document this in the DT binding. > > From PCIe base spec rev 3.0, chapter "6.6.1. Conventional Reset": > > "To allow components to perform internal initialization, system software must > wait a specified minimum period following the end of a Conventional Reset of > one or more devices before it is permitted to issue Configuration Requests to > those devices. > > With a Downstream Port that does not support Link speeds greater than > 5.0 GT/s, software must wait a minimum of 100 ms before sending a > Configuration Request to the device immediately below that Port." > > Signed-off-by: Lucas Stach > --- > Documentation/devicetree/bindings/pci/mvebu-pci.txt | 3 ++- > drivers/pci/host/pci-mvebu.c | 2 +- > 2 files changed, 3 insertions(+), 2 deletions(-) Acked-by: Jason Cooper thx, Jason. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel From mboxrd@z Thu Jan 1 00:00:00 1970 From: jason@lakedaemon.net (Jason Cooper) Date: Mon, 16 Jan 2017 11:44:22 +0000 Subject: [PATCH] PCI: mvebu: change delay after reset to the PCIe spec mandated 100ms In-Reply-To: <20170116111142.6866-1-l.stach@pengutronix.de> References: <20170116111142.6866-1-l.stach@pengutronix.de> Message-ID: <20170116114422.GA25924@io.lakedaemon.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Lucas, On Mon, Jan 16, 2017 at 12:11:42PM +0100, Lucas Stach wrote: > The current default of 20ms cause some devices, which are slow to initialize, > to not show up during the bus scanning. Change this to the PCIe spec mandated > 100ms and document this in the DT binding. > > From PCIe base spec rev 3.0, chapter "6.6.1. Conventional Reset": > > "To allow components to perform internal initialization, system software must > wait a specified minimum period following the end of a Conventional Reset of > one or more devices before it is permitted to issue Configuration Requests to > those devices. > > With a Downstream Port that does not support Link speeds greater than > 5.0 GT/s, software must wait a minimum of 100 ms before sending a > Configuration Request to the device immediately below that Port." > > Signed-off-by: Lucas Stach > --- > Documentation/devicetree/bindings/pci/mvebu-pci.txt | 3 ++- > drivers/pci/host/pci-mvebu.c | 2 +- > 2 files changed, 3 insertions(+), 2 deletions(-) Acked-by: Jason Cooper thx, Jason.