On Tuesday, April 07, 2015 at 04:42:36 PM, Ramneek Mehresh wrote: > > -----Original Message----- > > From: Marek Vasut [mailto:[email protected]] > > Sent: Tuesday, April 07, 2015 7:44 PM > > To: Mehresh Ramneek-B31383 > > Cc: u-boot; [email protected] > > Subject: Re: Regarding patch: http://patchwork.ozlabs.org/patch/373593/ > > > > On Tuesday, April 07, 2015 at 04:05:31 PM, Ramneek Mehresh wrote: > > > > -----Original Message----- > > > > From: Marek Vasut [mailto:[email protected]] > > > > Sent: Tuesday, April 07, 2015 7:22 PM > > > > To: Mehresh Ramneek-B31383 > > > > Cc: u-boot; [email protected] > > > > Subject: Re: Regarding patch: > > > > http://patchwork.ozlabs.org/patch/373593/ > > > > > > > > On Tuesday, April 07, 2015 at 08:18:03 AM, Ramneek Mehresh wrote: > > > > > > > > [...] > > > > > > > > > > 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? > > > > > > > > Hi, > > > > > > > > I don't know, but doesn't leaving the USB running cause trouble to > > > > Linux? I think you should at least document the reasoning why the > > > > USB stop is not implemented for this broken hardware. > > > > > > Hi Marek, it's not USB controller stop, it's Phy stop which is not > > > supported. Controller stopping is supported. > > > > OK, does it pose a problem for Linux ? If not, then please just document > > it and let's stick with what there now. > > No, it won't create issue in Linux because Linux usb driver resets the > controller (which in turn resets the phy). Please suggest what's the best > place to document this. Shall I document this inside some u-boot doc file?
A comment in the driver source would be fine. Best regards, Marek Vasut _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
