From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [RFC 1/5] usb: chipidea: Add support for Tegra20/30/114/124 Date: Thu, 26 May 2016 15:17:12 -0600 Message-ID: <574767D8.8020203@wwwdotorg.org> References: <20160526154005.11558-1-thierry.reding@gmail.com> <20160526154005.11558-2-thierry.reding@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160526154005.11558-2-thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Thierry Reding Cc: Peter Chen , Greg Kroah-Hartman , Alexandre Courbot , Jon Hunter , linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-tegra@vger.kernel.org On 05/26/2016 09:40 AM, Thierry Reding wrote: > From: Thierry Reding > > All of these Tegra SoC generations have a ChipIdea UDC IP block that can > be used for device mode communication with a host. Implement rudimentary > support that doesn't allow switching between host and device modes. Are you sure this is correct for Tegra20? I ask because for the /host/ mode driver, there's a "has_hostpc" flag which is set to false for Tegra20 and true for all other SoCs. In the U-Boot device mode driver (if not in the kernel driver; I didn't check), there's a concept of "has hostpc" too. I might expect that flag to be set the same way for both drivers. That said, I /think/ the host and device HW are unrelated, so it's possible has_hostpc might be set differently for them. Unfortunately, we haven't enabled the device mode driver for any Tegra20 system in U-Boot so I can't tell whether we should enable has_hostpc for Tegra20's device mode driver. Still, if this code works then I guess it's likely correct...