From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Date: Mon, 6 Apr 2015 17:11:37 +0200 Subject: [U-Boot] Regarding patch: http://patchwork.ozlabs.org/patch/373593/ In-Reply-To: References: <201501121529.59432.marex@denx.de> Message-ID: <201504061711.37768.marex@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Monday, April 06, 2015 at 10:58:30 AM, Ramneek Mehresh wrote: [...] > > > > The static void fsl_xhci_core_exit(struct fsl_xhci *fsl_xhci) must > > > > shut down the controller, which I don't see happening. Why? > > > > > > I could not locate any such requirement in IP documentation. Have > > > contacted local IP/PHY team for the same. Waiting for response from > > > them > > > > This is needed, so you don't start Linux with a running USB controller. > > xhci controller is already stopped in > usb_stop->usb_lowlevel_stop->xhci_reset(). I could see CMD_RUN bit getting > reset in this function before the controller is reset. So, from your > previously stated requirement, controller is halted when Linux is started. > > Other people are shutting down PHY as part of xhci_core_exit(), not the > controller!! We would not like to re-start and re-configure PHY inside > Linux, and take phy initialization inside bootloader. I got word from hw > team that they do not support phy shutting down from sw. hence, we do not > have any sequence for current socs to shut down phy from sw. if required, > I'll put forward a request to provide this control in future socs. Hi, Is this similar hardware bug to the one which MX6 PCIe is suffering ? On MX6, the bug is that you cannot reset the PCIe and PCIe PHY from software, which means that if you start PCIe in U-Boot, you cannot reliably use it in Linux. Furthermore, if you reset the MX6 via WDT, you cannot start PCIe reliably in Linux even if PCIe is not used in U-Boot at all. Is this the same type of hardware screwup where the design team didn't think reset was necessary? Best regards, Marek Vasut