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Re: [Qemu-devel] [PATCH v2 11/11] aspeed/smc: handle dummy bytes when do
From: |
Cédric Le Goater |
Subject: |
Re: [Qemu-devel] [PATCH v2 11/11] aspeed/smc: handle dummy bytes when doing fast reads in command mode |
Date: |
Tue, 17 Jan 2017 09:37:23 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.6.0 |
On 01/16/2017 07:58 PM, mar.krzeminski wrote:
>
>
> W dniu 16.01.2017 o 09:18, Cédric Le Goater pisze:
>>> I did not notice that this function is also called in writes, isn't it?
>>> If yes, dummy cycles are used only during reads so probably CTRL_FREADMODE
>>> needs to be tested.
>> yes. I can take care of that in a follow up patchset for
>> dummy support.
>> Dummies in user mode is a bit painful to implement, as I had
>> to snoop into the command flow to catch the fast read op.
>> Not sure this is the right approach so I kept it for later.
> Definitelly wrong, controller should not be aware of tha, fix is still on me
> :(
ok. np. I will send the support for command mode though,
as this is a must have for booting.
>>
>>
>> Did you have time to take look at the other patches adding
>> Command mode and extending the tests ? I should have addressed
>> your comments there.
> Yes, there is one more thing that could be important. It popped out in
> Sabrelite
> SPI model. The question is does SCM support different CS active (so device
> is active at CS high). Your code assume that SMC will always use CS LOW to
> activate
> device. If this is not true you might be interested in update this too.
Aspeed SoC does not let you configure the chip select polarity
(nor the clock phase ) So it is active low only.
Thanks,
C.
- Re: [Qemu-devel] [PATCH v2 09/11] aspeed/smc: extend tests for Command mode, (continued)
[Qemu-devel] [PATCH v2 10/11] aspeed: use first FMC flash as a boot ROM, Cédric Le Goater, 2017/01/09
[Qemu-devel] [PATCH v2 11/11] aspeed/smc: handle dummy bytes when doing fast reads in command mode, Cédric Le Goater, 2017/01/09
- Re: [Qemu-devel] [PATCH v2 11/11] aspeed/smc: handle dummy bytes when doing fast reads in command mode, mar.krzeminski, 2017/01/11
- Re: [Qemu-devel] [PATCH v2 11/11] aspeed/smc: handle dummy bytes when doing fast reads in command mode, Cédric Le Goater, 2017/01/11
- Re: [Qemu-devel] [PATCH v2 11/11] aspeed/smc: handle dummy bytes when doing fast reads in command mode, mar.krzeminski, 2017/01/14
- Re: [Qemu-devel] [PATCH v2 11/11] aspeed/smc: handle dummy bytes when doing fast reads in command mode, Cédric Le Goater, 2017/01/16
- Re: [Qemu-devel] [PATCH v2 11/11] aspeed/smc: handle dummy bytes when doing fast reads in command mode, mar.krzeminski, 2017/01/16
- Re: [Qemu-devel] [PATCH v2 11/11] aspeed/smc: handle dummy bytes when doing fast reads in command mode,
Cédric Le Goater <=
- Re: [Qemu-devel] [PATCH v2 11/11] aspeed/smc: handle dummy bytes when doing fast reads in command mode, mar.krzeminski, 2017/01/17
Re: [Qemu-devel] [PATCH v2 00/11] Aspeed SMC controller fixes and improvements, Peter Maydell, 2017/01/16