> -----Original Message----- > From: Marek Vasut [mailto:[email protected]] > Sent: Monday, April 06, 2015 8:42 PM > To: Mehresh Ramneek-B31383 > Cc: u-boot; [email protected] > Subject: Re: Regarding patch: http://patchwork.ozlabs.org/patch/373593/ > > 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? > I have raised request for this feature in up-coming socs, and they have agreed to provide phy shut-down in future revs. However, this support is not available in current revs for which the code is sent. What do you suggest we should do for current socs?
> Best regards, > Marek Vasut _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
