On Wed, Feb 22, 2017 at 8:57 PM, Dana Myers <k...@comcast.net> wrote:
> On 2/22/2017 6:18 PM, L. D. Pinney wrote: > > > spi-mt7621.c has bugs ... isn't very helpful. > > > I am a bit surprised you're not already aware of the SPI issues. > > I am not surprised at all ... ALL of my MT76x8 devices have only a single SPI-NOR Chip connected to the SPI. On every device it works as intended ... load the OS. Whenever you (or anyone) adds functionality to a device you can expect problems. In this case some device foreign to the actual device in question. More specifically a device such as a RFID module or STM32. If you have a working patch...You can start here : https://lede-project.org/docs/guide-developer/the-source-code You can start here: > > https://community.onion.io/topic/1560/spi-pins-for-the-omega2/20 > > which links to another forum thread which contains this *very* informative > posting: > > http://52.76.69.244/jforum/posts/list/30/3683.page#12266 > > and suggested patch: > > http://52.76.69.244/jforum/posts/list/30/3683.page#12299 > > which is the basis of the patch I'm using. > > Please describe the problem? > > berniwa does a much better job than me in the above-linked posting. > > > Can I reproduce the same problem on one of my many MT76x8 devices? > If so how? > > > I've only seen reports of the issue on MT7688-based devices (LinkIt 7688, > Omega2) > and I personally have observed it on the Omega2. > > The easiest way to reproduce it is to attempt to send an SPI sequence > starting with the '10' bit sequence (first nibble of 0x8 .. 0xb). You'll > find > the leading '1' bit is sent as a '0'. > > I'd be somewhat surprised if the same issue wasn't present on all devices > which > incorporate the MT7621 SPI peripheral given the likelihood that MediaTek > reproduces the same logic on every chip that includes the peripheral. > > The SPI driver also exposes the transfer limit of 16 bytes, which berniwa's > patch addresses by breaking up a transfer as needed (keeping chip select > asserted). > > > The MediaTek Linkit github is based on OpenWrt 15.05 using a 3.18 kernel. > The patches needed for 3.18 vs. 4.4 or 4.9 will be quite different. > > > Understood; I didn't say that MediaTek was using the *same* patch, but that > this issue is present on all MT7688 devices and that MediaTek has > incorporated > a patch for it. The patch I'm using is for 4.4, of course. > > If you could confirm the presence of the issue on other MT7621-based SPI > peripherals, that would address my initial inquiry indirectly if we could > just > patch all instances of the MT7621 SPI build :-) > > Cheers, > Dana K6JQ > > > > > > > On Wed, Feb 22, 2017 at 7:00 PM, Dana Myers <k...@comcast.net> wrote: > >> On 2/22/2017 4:27 PM, L. D. Pinney wrote: >> >> Are you using https://github.com/OnionIoT/source onion-omega2 branch ? >> >> >> I am not; I'm using https://github.com/lede-project/source (master >> branch) >> >> However, I don't believe it makes any difference - spi-mt7621.c appears >> to be identical in both and the same patch applies; and this isn't an >> Omega2-specific issue. All MT7688-based systems have this issue; MediaTek >> Labs patched their LinkIt repo for this. A fix really belongs upstream. >> >> Thanks - >> Dana >> >> >> On Wed, Feb 22, 2017 at 2:30 PM, Dana Myers <k...@comcast.net> wrote: >> >>> >>> I'm working with the Onion Omega2, which is based on an MT7688 SoC. >>> The MT7688 SoC is a variant of the MT76xx family; in particular, it >>> shares the same SPI peripheral. Support for SPI is in >>> ..../drivers/spi/mt7621.c >>> >>> However, there's bugs with the SPI in the MT7688 which require a patch >>> to spi-mt7621.c - and I don't know if the same bugs are present in the >>> other MT76xx family members. It is possible the other MT76xx SoCs have >>> the same hardware issue (I'd be surprised if not) but I can only test >>> the MT7688 I have. >>> >>> I think I want to patch the source file only when building only the >>> MT7688 >>> target, but I'm not sure how to do that or if it's supported. >>> >>> So I'm looking for advice on how I might incorporate this patch so >>> that it is only applied when building ramips/mt7688. >>> >>> Thanks, >>> Dana K6JQ >>> _______________________________________________ >>> openwrt-devel mailing list >>> openwrt-devel@lists.openwrt.org >>> https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel >>> >> >> >> > >
_______________________________________________ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel
