Re: [PATCH] hw/sd: sd: Bypass the RCA check for CMD13 in SPI mode

[Bin Meng]

Hi Philippe,

On Fri, Jan 29, 2021 at 10:11 PM Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
>
> Hi Bin,
>
> On 1/29/21 9:51 AM, Bin Meng wrote:
> > From: Bin Meng <bin.meng@windriver.com>
> >
> > Unlike SD mode, when SD card is working in SPI mode, the argument
> > of CMD13 is stuff bits. Hence we should bypass the RCA check.
>
> Is this for detecting events by polling? From spec v8:
>
>   5.7.5 Event Indication Method
>   5.7.5.1 FX_EVENT (Bit06 of Card Status)
>
>     An event indication method is introduced from Version 4.20.
>     Card may use Bit06 of R1 (R1b) response of any SD command
>     to indicate event generation.
>
>   F.2 Concept of Event Detection Method
>   F.2.2 Host Implementation to use Event Detection Method
>

I think you looked at the wrong place. See spec v8

chapter 7.3.1.3 Detailed Command Description

"The card shall ignore stuff bits and reserved bits in an argument"

and Table 7-3 Commands and Arguments

CMD13 Argument [31:0] stuff bits

Regards,
Bin