From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Dooks Date: Tue, 28 Jan 2014 08:35:42 +0000 Subject: Re: [PATCH V2 2/3] ARM: shmobile: r8a7790: Add PCI USB host clock support Message-Id: <52E76BDE.1040905@codethink.co.uk> List-Id: References: <1389982854-20680-3-git-send-email-valentine.barshak@cogentembedded.com> In-Reply-To: <1389982854-20680-3-git-send-email-valentine.barshak@cogentembedded.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sh@vger.kernel.org On 28/01/14 00:28, Magnus Damm wrote: > On Fri, Jan 24, 2014 at 8:37 PM, Ben Dooks wrote: >> On 24/01/14 04:47, Magnus Damm wrote: >>> >>> On Sat, Jan 18, 2014 at 3:20 AM, Valentine Barshak >>> wrote: >>>> >>>> This adds internal PCI USB host clock support. >>>> >>>> Signed-off-by: Valentine Barshak >>>> --- >>>> arch/arm/mach-shmobile/clock-r8a7790.c | 6 +++++- >>>> 1 file changed, 5 insertions(+), 1 deletion(-) >>>> >>>> Changes in V2: >>>> * capitalized ARM in the subject; >>>> * rebased on top the latest devel tag. >>> >>> >>> This patch for PCI USB clock support seems fine to me. >>> >>> Acked-by: Magnus Damm >>> >>> It is common practice that maintainers reject code to encourage people >>> to do further development. I don't think that will help us in this >>> particular case, so I think it is best to merge this as-is but also >>> request you to spend your future time on DT development. >>> >>> So please work on DT reference support together with CCF for PCI USB. >> >> >> I've already posted a series for getting this device treeed. > > Thanks for that! > >> As a note, does channel 0 work for you? we are getting a lot of >> failures with the OHCI controller failing to start with what looks >> like a bus-master failure. > > I've only used USB0 as USBHS, and due to lack of cable detection > hardware support on Lager (and me missing the cable needed for host) I > plan on simply fixing USB0 as USBHS Function. Anyone wanting to test > USB PCI Host should in my opinion use USB1 on Lager. USB2 is also fine > until USB 3.0 support is tied in there. > > As both you and I have noted, the USB PCI stuff can't work well as-is > due to mismatch in physical address space between the PCI hardware and > the actual memory on Lager. So as we discussed, bounce buffers would > be needed and perhaps also IOMMU support but my feeling is that may as > well be for later in case of USB. > > So until I see USB PCI bounce buffer support or similar I will simply > assume all errors on USB PCI on r8a7790 and r8a7791 are related to > physical address size mismatch and lacking software support. Do you > have anything that points in a different direction? > > Does USB1 and/or USB2 work for you as-is today? Yes, although I have been doing my initial testing with the RAM size limited to 1GiB of memory. I've found a couple of minor issues with the PCI bridge driver that so far have not actually fixed my problem which I hope to get reviewed and sent to the lists today. I am going to try the 'legacy' boot method today and see if I get the same problems, just to verify if the problem is with the fdt conversion or there is an issue with my board/code. -- Ben Dooks http://www.codethink.co.uk/ Senior Engineer Codethink - Providing Genius