[v2] nrf51: Fix last GPIO CNF address

Commit Message

Denis V. Lunev" via April 15, 2020, 4:37 a.m. UTC

NRF51_GPIO_REG_CNF_END doesn't actually refer to the start of the last
valid CNF register: it's referring to the last byte of the last valid
CNF register.

This hasn't been a problem up to now, as current implementation in
memory.c turns an unaligned 4-byte read from 0x77f to a single byte read
and the qtest only looks at the least-significant byte of the register.

But when running with patches which fix unaligned accesses in memory.c,
the qtest breaks.

Considering NRF51 doesn't support unaligned accesses, the simplest fix
is to actually set NRF51_GPIO_REG_CNF_END to the start of the last valid
CNF register: 0x77c.

Now, qtests work with or without the unaligned access patches.

Reviewed-by: Cédric Le Goater <[e-mail]>
Tested-by: Cédric Le Goater <[e-mail]>
Reviewed-by: Joel Stanley <[e-mail]>
Signed-off-by: Cameron Esfahani <[e-mail]>
---
 include/hw/gpio/nrf51_gpio.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Peter Maydell April 16, 2020, 5:09 p.m. UTC | #1

On Wed, 15 Apr 2020 at 05:37, Cameron Esfahani <[e-mail]> wrote:
>
> NRF51_GPIO_REG_CNF_END doesn't actually refer to the start of the last
> valid CNF register: it's referring to the last byte of the last valid
> CNF register.
>
> This hasn't been a problem up to now, as current implementation in
> memory.c turns an unaligned 4-byte read from 0x77f to a single byte read
> and the qtest only looks at the least-significant byte of the register.
>
> But when running with patches which fix unaligned accesses in memory.c,
> the qtest breaks.
>
> Considering NRF51 doesn't support unaligned accesses, the simplest fix
> is to actually set NRF51_GPIO_REG_CNF_END to the start of the last valid
> CNF register: 0x77c.
>
> Now, qtests work with or without the unaligned access patches.
>
> Reviewed-by: Cédric Le Goater <[e-mail]>
> Tested-by: Cédric Le Goater <[e-mail]>
> Reviewed-by: Joel Stanley <[e-mail]>
> Signed-off-by: Cameron Esfahani <[e-mail]>



Applied to target-arm.next for 5.1, thanks.

-- PMM

Patch

diff --git a/include/hw/gpio/nrf51_gpio.h b/include/hw/gpio/nrf51_gpio.h
index 337ee534bb..1d62bbc928 100644
--- a/include/hw/gpio/nrf51_gpio.h
+++ b/include/hw/gpio/nrf51_gpio.h
@@ -42,7 +42,7 @@ 
 #define NRF51_GPIO_REG_DIRSET       0x518
 #define NRF51_GPIO_REG_DIRCLR       0x51C
 #define NRF51_GPIO_REG_CNF_START    0x700
-#define NRF51_GPIO_REG_CNF_END      0x77F
+#define NRF51_GPIO_REG_CNF_END      0x77C
 
 #define NRF51_GPIO_PULLDOWN 1
 #define NRF51_GPIO_PULLUP 3