[PATCH 2/2] hw/sd: Fix ACMD41 state machine in SPI mode

Bin Meng posted 2 patches 1 month ago
Maintainers: "Philippe Mathieu-Daudé" <philmd@linaro.org>, Bin Meng <bmeng.cn@gmail.com>
[PATCH 2/2] hw/sd: Fix ACMD41 state machine in SPI mode
Posted by Bin Meng 1 month ago
In SPI mode, the ACMD41 argument only defines bit 30 (HCS); all other
bits are reserved. The current implementation incorrectly checks the
voltage window bits even in SPI mode, preventing the state machine
from transitioning to the READY state. As a result, the U-Boot
mmc-spi driver falls into an endless CMD55/ACMD41 loop.

Fixes: 3241a61a ("hw/sd/sdcard: Use complete SEND_OP_COND implementation in SPI mode")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2945
Reported-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>

---

 hw/sd/sd.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 5aae541363..11c3a64080 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -2289,20 +2289,21 @@ static sd_rsp_type_t sd_cmd_SEND_OP_COND(SDState *sd, SDRequest req)
         }
     }
 
-    if (FIELD_EX32(sd->ocr & req.arg, OCR, VDD_VOLTAGE_WINDOW)) {
-        /*
-         * We accept any voltage.  10000 V is nothing.
-         *
-         * Once we're powered up, we advance straight to ready state
-         * unless it's an enquiry ACMD41 (bits 23:0 == 0).
-         */
-        sd->state = sd_ready_state;
-    }
-
     if (sd_is_spi(sd)) {
+        sd->state = sd_ready_state;
         return sd_r1;
+    } else {
+        if (FIELD_EX32(sd->ocr & req.arg, OCR, VDD_VOLTAGE_WINDOW)) {
+            /*
+            * We accept any voltage.  10000 V is nothing.
+            *
+            * Once we're powered up, we advance straight to ready state
+            * unless it's an enquiry ACMD41 (bits 23:0 == 0).
+            */
+            sd->state = sd_ready_state;
+        }
+        return sd_r3;
     }
-    return sd_r3;
 }
 
 /* ACMD42 */
-- 
2.34.1
Re: [PATCH 2/2] hw/sd: Fix ACMD41 state machine in SPI mode
Posted by Philippe Mathieu-Daudé 3 weeks, 4 days ago
On 10/11/25 12:05, Bin Meng wrote:
> In SPI mode, the ACMD41 argument only defines bit 30 (HCS); all other
> bits are reserved. The current implementation incorrectly checks the
> voltage window bits even in SPI mode, preventing the state machine
> from transitioning to the READY state. As a result, the U-Boot
> mmc-spi driver falls into an endless CMD55/ACMD41 loop.
> 
> Fixes: 3241a61a ("hw/sd/sdcard: Use complete SEND_OP_COND implementation in SPI mode")
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2945
> Reported-by: Tom Rini <trini@konsulko.com>
> Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
> 
> ---
> 
>   hw/sd/sd.c | 23 ++++++++++++-----------
>   1 file changed, 12 insertions(+), 11 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>