Re: [PATCH] hw/sd/pxa2xx_mmci: Disable reentrancy detection

[Guenter Roeck <linux@roeck-us.net>]

On 12/13/23 09:19, Philippe Mathieu-Daudé wrote:
> Hi Guenter,
> 
> On 13/12/23 18:12, Peter Maydell wrote:
>> On Wed, 13 Dec 2023 at 01:49, Guenter Roeck <linux@roeck-us.net> wrote:
>>>
>>> All tests using pxa2xx_mmc to access mmc cards on pxa2xx platforms
>>> such as borzoi fail starting with commit a2e1753b80 ("memory: prevent
>>> dma-reentracy issues"). Disable reentrancy guard to fix the problem.
>>>
>>> Fixes: a2e1753b80 ("memory: prevent dma-reentracy issues")
>>> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
>>> ---
>>>   hw/sd/pxa2xx_mmci.c | 2 ++
>>>   1 file changed, 2 insertions(+)
>>>
>>> diff --git a/hw/sd/pxa2xx_mmci.c b/hw/sd/pxa2xx_mmci.c
>>> index 5e8ea69188..27ae8f2888 100644
>>> --- a/hw/sd/pxa2xx_mmci.c
>>> +++ b/hw/sd/pxa2xx_mmci.c
>>> @@ -555,6 +555,8 @@ static void pxa2xx_mmci_instance_init(Object *obj)
>>>       qdev_init_gpio_out_named(dev, &s->rx_dma, "rx-dma", 1);
>>>       qdev_init_gpio_out_named(dev, &s->tx_dma, "tx-dma", 1);
>>>
>>> +    s->iomem.disable_reentrancy_guard = true;
>>> +
>>
>> All patches that set this flag should include a comment which
>> explains what the device access path that triggers the reentrancy
>> is, please.
> 
> Can we get a reproducer or backtrace please?

qemu-system-arm: warning: Blocked re-entrant IO on MemoryRegion: pxa2xx-mmci at addr: 0x40
[    0.770246] mmc0: invalid bus width
[    0.770962] mmc0: error -22 whilst initialising SD card
[    0.828179] mmc0: invalid bus width
[    0.828445] mmc0: error -22 whilst initialising SD card

with:

qemu-system-arm -M borzoi -kernel arch/arm/boot/zImage -no-reboot -snapshot \
	-device sd-card,drive=d0 -drive file=/tmp/flash,format=raw,if=none,id=d0 \
	-usb -device usb-net,netdev=net0 -netdev user,id=net0 \
	--append "root=/dev/mmcblk0 rootwait console=ttyS0"

Guenter