Since its introduction in commit 6fc7f77fd2 i2c_start_transfer()
uses incorrectly the direction of the transfer (the last argument
is called 'is_recv'). Fix by inverting the argument, we now have
is_recv = !is_write.

Fixes: 6fc7f77fd2 ("introduce aux-bus")
Reported-by: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/misc/auxbus.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/hw/misc/auxbus.c b/hw/misc/auxbus.c
index 6c099ae2a2d..148b070ce4a 100644
--- a/hw/misc/auxbus.c
+++ b/hw/misc/auxbus.c
@@ -139,7 +139,7 @@ AUXReply aux_request(AUXBus *bus, AUXCommand cmd, uint32_t address,
             i2c_end_transfer(i2c_bus);
         }
 
-        if (i2c_start_transfer(i2c_bus, address, is_write)) {
+        if (i2c_start_transfer(i2c_bus, address, !is_write)) {
             ret = AUX_I2C_NACK;
             break;
         }
@@ -170,7 +170,7 @@ AUXReply aux_request(AUXBus *bus, AUXCommand cmd, uint32_t address,
             /*
              * No transactions started..
              */
-            if (i2c_start_transfer(i2c_bus, address, is_write)) {
+            if (i2c_start_transfer(i2c_bus, address, !is_write)) {
                 break;
             }
         } else if ((address != bus->last_i2c_address) ||
@@ -179,7 +179,7 @@ AUXReply aux_request(AUXBus *bus, AUXCommand cmd, uint32_t address,
              * Transaction started but we need to restart..
              */
             i2c_end_transfer(i2c_bus);
-            if (i2c_start_transfer(i2c_bus, address, is_write)) {
+            if (i2c_start_transfer(i2c_bus, address, !is_write)) {
                 break;
             }
         }
-- 
2.31.1

On 6/16/21 9:14 AM, Philippe Mathieu-Daudé wrote:
> Since its introduction in commit 6fc7f77fd2 i2c_start_transfer()
> uses incorrectly the direction of the transfer (the last argument
> is called 'is_recv'). Fix by inverting the argument, we now have
> is_recv = !is_write.
> 
> Fixes: 6fc7f77fd2 ("introduce aux-bus")
> Reported-by: BALATON Zoltan<balaton@eik.bme.hu>
> Signed-off-by: Philippe Mathieu-Daudé<f4bug@amsat.org>
> ---
>   hw/misc/auxbus.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~