Re: [Qemu-devel] [PATCH arm-devs v1 1/5] sd/sd.c: Fix "inquiry" ACMD41

[Igor Mitsyanko <i.mitsyanko@gmail.com>]

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On 05/21/2013 10:50 AM, peter.crosthwaite@xilinx.com wrote:

From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
<peter.crosthwaite@xilinx.com>

the SD command ACMD41 can be used in a read only mode to query device
state without doing the SD card initialisation. This is valid even
which the device is already initialised. Fix the command to be
responsive when in the ready state accordingly.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
<peter.crosthwaite@xilinx.com>
---

 hw/sd/sd.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 2e0ef3e..89bfb7a 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -1277,6 +1277,7 @@ static sd_rsp_type_t sd_app_command(SDState *sd,
         }
         switch (sd->state) {
         case sd_idle_state:
+        case sd_ready_state:
             /* We accept any voltage.  10000 V is nothing.  */
             if (req.arg)
                 sd->state = sd_ready_state;


I couldn't find any info in SD specification that would confirm this change
correctness, what about
table "Table 4-29: Card State Transition Table" which states that ACMD41 is
illegal in "ready" state?

-- 
Best wishes,
Igor Mitsyanko
email: i.mitsyanko@gmail.com

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