[PATCH-for-10.1 RESEND RESEND v2 0/3] hw/sd/ssi-sd: Return noise (dummy byte) when no card connected

[PATCH-for-10.1 RESEND RESEND v2 0/3] hw/sd/ssi-sd: Return noise (dummy byte) when no card connected

[Philippe Mathieu-Daudé]

Trivial fix for the issue reported by Guenter here:
https://lore.kernel.org/qemu-devel/5b2dc427-f0db-4332-a997-fe0c82415acd@roeck-us.net/

- Return dummy byte when no card is connected
- Add a test
- Document ssi_transfer()

Since v1:
- Reworded patch #1 description (Alex)
- Removed '_' test method prefix (Alex)

Philippe Mathieu-Daudé (3):
  hw/sd/ssi-sd: Return noise (dummy byte) when no card connected
  tests/functional: Test SPI-SD adapter without SD card connected
  hw/ssi: Document ssi_transfer() method

 include/hw/ssi/ssi.h                      | 14 ++++++++++++++
 hw/sd/ssi-sd.c                            |  4 ++++
 tests/functional/test_riscv64_sifive_u.py | 22 +++++++++++++++++-----
 3 files changed, 35 insertions(+), 5 deletions(-)

-- 
2.49.0

[PATCH-for-10.1 RESEND RESEND v2 1/3] hw/sd/ssi-sd: Return noise (dummy byte) when no card connected

[Philippe Mathieu-Daudé]

Commit 1585ab9f1ba ("hw/sd/sdcard: Fill SPI response bits in card
code") exposed a bug in the SPI adapter: if no SD card is plugged,
we are returning "there is a card with an error". This is wrong,
we shouldn't return any particular packet response, but the noise
shifted on the MISO line. Return the dummy byte, otherwise we get:

  qemu-system-riscv64: ../hw/sd/ssi-sd.c:160: ssi_sd_transfer: Assertion `s->arglen > 0' failed.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Fixes: 775616c3ae8 ("Partial SD card SPI mode support")
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
---
 hw/sd/ssi-sd.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/hw/sd/ssi-sd.c b/hw/sd/ssi-sd.c
index 594dead19ee..3aacbd03871 100644
--- a/hw/sd/ssi-sd.c
+++ b/hw/sd/ssi-sd.c
@@ -89,6 +89,10 @@ static uint32_t ssi_sd_transfer(SSIPeripheral *dev, uint32_t val)
     SDRequest request;
     uint8_t longresp[5];
 
+    if (!sdbus_get_inserted(&s->sdbus)) {
+        return SSI_DUMMY;
+    }
+
     /*
      * Special case: allow CMD12 (STOP TRANSMISSION) while reading data.
      *
-- 
2.49.0

[PATCH-for-10.1 RESEND RESEND v2 2/3] tests/functional: Test SPI-SD adapter without SD card connected

[Philippe Mathieu-Daudé]

SPI-SD adapter should be usable, even without any SD card
wired. Refactor test_riscv64_sifive_u_mmc_spi() to make it
more generic and add another test, inspired by this report:
https://lore.kernel.org/qemu-devel/5b2dc427-f0db-4332-a997-fe0c82415acd@roeck-us.net/

Inspired-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 tests/functional/test_riscv64_sifive_u.py | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/tests/functional/test_riscv64_sifive_u.py b/tests/functional/test_riscv64_sifive_u.py
index dc4cb8a4a96..ca4c3ba6e12 100755
--- a/tests/functional/test_riscv64_sifive_u.py
+++ b/tests/functional/test_riscv64_sifive_u.py
@@ -27,25 +27,37 @@ class SifiveU(LinuxKernelTest):
          'rootfs.ext2.gz'),
         'b6ed95610310b7956f9bf20c4c9c0c05fea647900df441da9dfe767d24e8b28b')
 
-    def test_riscv64_sifive_u_mmc_spi(self):
+    def do_test_riscv64_sifive_u_mmc_spi(self, connect_card):
         self.set_machine('sifive_u')
         kernel_path = self.ASSET_KERNEL.fetch()
         rootfs_path = self.uncompress(self.ASSET_ROOTFS)
 
         self.vm.set_console()
         kernel_command_line = (self.KERNEL_COMMON_COMMAND_LINE +
-                               'root=/dev/mmcblk0 rootwait '
                                'earlycon=sbi console=ttySIF0 '
-                               'panic=-1 noreboot')
+                               'root=/dev/mmcblk0 ')
         self.vm.add_args('-kernel', kernel_path,
-                         '-drive', f'file={rootfs_path},if=sd,format=raw',
                          '-append', kernel_command_line,
                          '-no-reboot')
+        if connect_card:
+            self.vm.add_args('-drive', f'file={rootfs_path},if=sd,format=raw')
+            kernel_command_line += 'panic=-1 noreboot rootwait '
+            pattern = 'Boot successful.'
+        else:
+            kernel_command_line += 'panic=0 noreboot '
+            pattern = 'Cannot open root device "mmcblk0" or unknown-block(0,0)'
+
         self.vm.launch()
-        self.wait_for_console_pattern('Boot successful.')
+        self.wait_for_console_pattern(pattern)
 
         os.remove(rootfs_path)
 
+    def test_riscv64_sifive_u_nommc_spi(self):
+        self.do_test_riscv64_sifive_u_mmc_spi(False)
+
+    def test_riscv64_sifive_u_mmc_spi(self):
+        self.do_test_riscv64_sifive_u_mmc_spi(True)
+
 
 if __name__ == '__main__':
     LinuxKernelTest.main()
-- 
2.49.0

[PATCH-for-10.1 RESEND RESEND v2 3/3] hw/ssi: Document ssi_transfer() method

[Philippe Mathieu-Daudé]

A SPI transaction consists of shifting bit in sync with the CLK
line, writing on the MOSI (output) line / and reading MISO (input)
line.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/hw/ssi/ssi.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/include/hw/ssi/ssi.h b/include/hw/ssi/ssi.h
index 3cdcbd53904..2ad8033d8f5 100644
--- a/include/hw/ssi/ssi.h
+++ b/include/hw/ssi/ssi.h
@@ -38,6 +38,7 @@ struct SSIPeripheralClass {
 
     /* if you have standard or no CS behaviour, just override transfer.
      * This is called when the device cs is active (true by default).
+     * See ssi_transfer().
      */
     uint32_t (*transfer)(SSIPeripheral *dev, uint32_t val);
     /* called when the CS line changes. Optional, devices only need to implement
@@ -52,6 +53,7 @@ struct SSIPeripheralClass {
      * of the CS behaviour at the device level. transfer, set_cs, and
      * cs_polarity are unused if this is overwritten. Transfer_raw will
      * always be called for the device for every txrx access to the parent bus
+     * See ssi_transfer().
      */
     uint32_t (*transfer_raw)(SSIPeripheral *dev, uint32_t val);
 };
@@ -110,6 +112,18 @@ bool ssi_realize_and_unref(DeviceState *dev, SSIBus *bus, Error **errp);
 /* Master interface.  */
 SSIBus *ssi_create_bus(DeviceState *parent, const char *name);
 
+/**
+ * Transfer a word on a SSI bus
+ * @bus: SSI bus
+ * @val: word to transmit
+ *
+ * At the same time, read a word and write the @val one on the SSI bus.
+ *
+ * SSI words might vary between 8 and 32 bits. The same number of bits
+ * written is received.
+ *
+ * Return: word value received
+ */
 uint32_t ssi_transfer(SSIBus *bus, uint32_t val);
 
 DeviceState *ssi_get_cs(SSIBus *bus, uint8_t cs_index);
-- 
2.49.0

Re: [PATCH-for-10.1 RESEND RESEND v2 2/3] tests/functional: Test SPI-SD adapter without SD card connected

[Gustavo Romero]

Hi Phil,

On 8/12/25 11:04, Philippe Mathieu-Daudé wrote:
> SPI-SD adapter should be usable, even without any SD card
> wired. Refactor test_riscv64_sifive_u_mmc_spi() to make it
> more generic and add another test, inspired by this report:
> https://lore.kernel.org/qemu-devel/5b2dc427-f0db-4332-a997-fe0c82415acd@roeck-us.net/
> 
> Inspired-by: Guenter Roeck <linux@roeck-us.net>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>   tests/functional/test_riscv64_sifive_u.py | 22 +++++++++++++++++-----
>   1 file changed, 17 insertions(+), 5 deletions(-)
> 
> diff --git a/tests/functional/test_riscv64_sifive_u.py b/tests/functional/test_riscv64_sifive_u.py
> index dc4cb8a4a96..ca4c3ba6e12 100755
> --- a/tests/functional/test_riscv64_sifive_u.py
> +++ b/tests/functional/test_riscv64_sifive_u.py
> @@ -27,25 +27,37 @@ class SifiveU(LinuxKernelTest):
>            'rootfs.ext2.gz'),
>           'b6ed95610310b7956f9bf20c4c9c0c05fea647900df441da9dfe767d24e8b28b')
>   
> -    def test_riscv64_sifive_u_mmc_spi(self):
> +    def do_test_riscv64_sifive_u_mmc_spi(self, connect_card):
>           self.set_machine('sifive_u')
>           kernel_path = self.ASSET_KERNEL.fetch()
>           rootfs_path = self.uncompress(self.ASSET_ROOTFS)
>   
>           self.vm.set_console()
>           kernel_command_line = (self.KERNEL_COMMON_COMMAND_LINE +
> -                               'root=/dev/mmcblk0 rootwait '
>                                  'earlycon=sbi console=ttySIF0 '
> -                               'panic=-1 noreboot')
> +                               'root=/dev/mmcblk0 ')
>           self.vm.add_args('-kernel', kernel_path,
> -                         '-drive', f'file={rootfs_path},if=sd,format=raw',
>                            '-append', kernel_command_line,
>                            '-no-reboot')
> +        if connect_card:
> +            self.vm.add_args('-drive', f'file={rootfs_path},if=sd,format=raw')
> +            kernel_command_line += 'panic=-1 noreboot rootwait '

I would put kernel_command_line before add_args just to follow the order above,
but really it's a nit and for sure not worth a v3, but mentioning it just in
case there will be a v3 and you want to change it.


> +            pattern = 'Boot successful.'
> +        else:
> +            kernel_command_line += 'panic=0 noreboot '
> +            pattern = 'Cannot open root device "mmcblk0" or unknown-block(0,0)'
> +
>           self.vm.launch()
> -        self.wait_for_console_pattern('Boot successful.')
> +        self.wait_for_console_pattern(pattern)
>   
>           os.remove(rootfs_path)
>   
> +    def test_riscv64_sifive_u_nommc_spi(self):
> +        self.do_test_riscv64_sifive_u_mmc_spi(False)
> +
> +    def test_riscv64_sifive_u_mmc_spi(self):
> +        self.do_test_riscv64_sifive_u_mmc_spi(True)
> +
>   
>   if __name__ == '__main__':
>       LinuxKernelTest.main()

Reviewed-by: Gustavo Romero <gustavo.romero@linaro.org>


Cheers,
Gustavo

Re: [PATCH-for-10.1 RESEND RESEND v2 3/3] hw/ssi: Document ssi_transfer() method

[Gustavo Romero]

Hi Phil,

On 8/12/25 11:04, Philippe Mathieu-Daudé wrote:
> A SPI transaction consists of shifting bit in sync with the CLK
> line, writing on the MOSI (output) line / and reading MISO (input)
> line.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>   include/hw/ssi/ssi.h | 14 ++++++++++++++
>   1 file changed, 14 insertions(+)
> 
> diff --git a/include/hw/ssi/ssi.h b/include/hw/ssi/ssi.h
> index 3cdcbd53904..2ad8033d8f5 100644
> --- a/include/hw/ssi/ssi.h
> +++ b/include/hw/ssi/ssi.h
> @@ -38,6 +38,7 @@ struct SSIPeripheralClass {
>   
>       /* if you have standard or no CS behaviour, just override transfer.
>        * This is called when the device cs is active (true by default).
> +     * See ssi_transfer().
>        */
>       uint32_t (*transfer)(SSIPeripheral *dev, uint32_t val);
>       /* called when the CS line changes. Optional, devices only need to implement
> @@ -52,6 +53,7 @@ struct SSIPeripheralClass {
>        * of the CS behaviour at the device level. transfer, set_cs, and
>        * cs_polarity are unused if this is overwritten. Transfer_raw will
>        * always be called for the device for every txrx access to the parent bus
> +     * See ssi_transfer().
>        */
>       uint32_t (*transfer_raw)(SSIPeripheral *dev, uint32_t val);
>   };
> @@ -110,6 +112,18 @@ bool ssi_realize_and_unref(DeviceState *dev, SSIBus *bus, Error **errp);
>   /* Master interface.  */
>   SSIBus *ssi_create_bus(DeviceState *parent, const char *name);
>   
> +/**
> + * Transfer a word on a SSI bus
> + * @bus: SSI bus
> + * @val: word to transmit
> + *
> + * At the same time, read a word and write the @val one on the SSI bus.
> + *
> + * SSI words might vary between 8 and 32 bits. The same number of bits
> + * written is received.
> + *
> + * Return: word value received
> + */
>   uint32_t ssi_transfer(SSIBus *bus, uint32_t val);
>   
>   DeviceState *ssi_get_cs(SSIBus *bus, uint8_t cs_index);

Reviewed-by: Gustavo Romero <gustavo.romero@linaro.org>


Cheers,
Gustavo

Re: [PATCH-for-10.1 RESEND RESEND v2 1/3] hw/sd/ssi-sd: Return noise (dummy byte) when no card connected

[Gustavo Romero]

Hi Phil,

On 8/12/25 11:04, Philippe Mathieu-Daudé wrote:
> Commit 1585ab9f1ba ("hw/sd/sdcard: Fill SPI response bits in card
> code") exposed a bug in the SPI adapter: if no SD card is plugged,
> we are returning "there is a card with an error". This is wrong,
> we shouldn't return any particular packet response, but the noise
> shifted on the MISO line. Return the dummy byte, otherwise we get:
> 
>    qemu-system-riscv64: ../hw/sd/ssi-sd.c:160: ssi_sd_transfer: Assertion `s->arglen > 0' failed.
> 
> Reported-by: Guenter Roeck <linux@roeck-us.net>
> Fixes: 775616c3ae8 ("Partial SD card SPI mode support")
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> Tested-by: Guenter Roeck <linux@roeck-us.net>
> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
> ---
>   hw/sd/ssi-sd.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/hw/sd/ssi-sd.c b/hw/sd/ssi-sd.c
> index 594dead19ee..3aacbd03871 100644
> --- a/hw/sd/ssi-sd.c
> +++ b/hw/sd/ssi-sd.c
> @@ -89,6 +89,10 @@ static uint32_t ssi_sd_transfer(SSIPeripheral *dev, uint32_t val)
>       SDRequest request;
>       uint8_t longresp[5];
>   
> +    if (!sdbus_get_inserted(&s->sdbus)) {
> +        return SSI_DUMMY;
> +    }
> +
>       /*
>        * Special case: allow CMD12 (STOP TRANSMISSION) while reading data.
>        *

Reviewed-by: Gustavo Romero <gustavo.romero@linaro.org>


Cheers,
Gustavo

Re: [PATCH-for-10.1 RESEND RESEND v2 3/3] hw/ssi: Document ssi_transfer() method

[Alex Bennée]

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

> A SPI transaction consists of shifting bit in sync with the CLK
> line, writing on the MOSI (output) line / and reading MISO (input)
> line.
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro

Re: [PATCH-for-10.1 RESEND RESEND v2 2/3] tests/functional: Test SPI-SD adapter without SD card connected

[Alex Bennée]

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

> SPI-SD adapter should be usable, even without any SD card
> wired. Refactor test_riscv64_sifive_u_mmc_spi() to make it
> more generic and add another test, inspired by this report:
> https://lore.kernel.org/qemu-devel/5b2dc427-f0db-4332-a997-fe0c82415acd@roeck-us.net/
>
> Inspired-by: Guenter Roeck <linux@roeck-us.net>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro

Re: [PATCH-for-10.1 RESEND RESEND v2 0/3] hw/sd/ssi-sd: Return noise (dummy byte) when no card connected

[Philippe Mathieu-Daudé]

On 12/8/25 16:04, Philippe Mathieu-Daudé wrote:

> Philippe Mathieu-Daudé (3):
>    hw/sd/ssi-sd: Return noise (dummy byte) when no card connected
>    tests/functional: Test SPI-SD adapter without SD card connected
>    hw/ssi: Document ssi_transfer() method

Series queued, thanks!