From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36053) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fQa56-0008Om-LY for qemu-devel@nongnu.org; Wed, 06 Jun 2018 11:10:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fQa51-0005dh-J3 for qemu-devel@nongnu.org; Wed, 06 Jun 2018 11:10:36 -0400 Sender: =?UTF-8?Q?Philippe_Mathieu=2DDaud=C3=A9?= References: <6f3e8e1070c12d1a8321f4fdb6f65d56adc2767b.1528069840.git.balaton@eik.bme.hu> <20180606063606.GJ17757@umbus.fritz.box> From: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= Message-ID: Date: Wed, 6 Jun 2018 12:10:26 -0300 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCH 1/4] ppc4xx_i2c: Rewrite PPC4xx I2C emulation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: BALATON Zoltan , David Gibson Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org, Alexander Graf Hi Zoltan, On 06/06/2018 11:03 AM, BALATON Zoltan wrote: > On Wed, 6 Jun 2018, David Gibson wrote: >> On Mon, Jun 04, 2018 at 01:50:40AM +0200, BALATON Zoltan wrote: >>> I2C emulation currently is just enough for U-Boot to access SPD >>> EEPROMs but features that guests use to access I2C devices are not >>> correctly emulated. Rewrite to implement missing features to make it >>> work with all clients. >>> >>> Signed-off-by: BALATON Zoltan >>> --- >>> Maybe this could be split up into more patches but because the >>> previous implementation was wrong only allowing U-Boot to pass and no >>> clients could access I2C devices before this rewrite it probably does >>> not worth to try to make it a lot of small changes instead of dropping >>> the previous hack and rewrite following features of real hardware more >>> closely. (It turns out that each client driver accesses I2C in a >>> different way so we need to implement almost all features of the >>> hardware to please everyone.) >> >> The trouble is that because I don't really have a good test setup for >> this, I'm pretty reluctant to apply such a total rewrite without acks >> from more people who've tested it.  That or reviewing the changes >> myself, which I can't really do when it's in one big lump like this. > > OK, I've sent a v2 where this patch is split up to smaller pieces that > are hopefully easier to review. However this i2c emulation was only a > stub originally which was hacked together to make U-Boot happy when > added the sam460ex machine and this is the first version that attempts > to really model the device so that guests can also use it. Therefore I > think there's not a high chance of breaking anything important. I've > tested this with AROS, Linux, AmigaOS and MorphOS and they seem to be > able to read the RTC so it should work better than the previous version. Are those images publicly accessible? (thinking about adding acceptance qtests). > (Only AROS boots fully on sam460ex of these yet, others still need some > more work.)