Re: [PATCH v2 06/13] hw/arm/mcimx6ul-evk: Replace drive_get_next() by drive_get()

[Peter Maydell]

On Wed, 17 Nov 2021 at 16:34, Markus Armbruster  wrote:
>
> drive_get_next() is basically a bad idea.  It returns the "next" block
> backend of a certain interface type.  "Next" means bus=0,unit=N, where
> subsequent calls count N up from zero, per interface type.
>
> This lets you define unit numbers implicitly by execution order.  If the
> order changes, or new calls appear "in the middle", unit numbers change.
> ABI break.  Hard to spot in review.
>
> Machine "mcimx6ul-evk" connects backends with drive_get_next() in a
> counting loop.  Change it to use drive_get() directly.  This makes the
> unit numbers explicit in the code.
>
> Cc: Peter Maydell 
> Cc: Jean-Christophe Dubois 
> Cc: qemu-...@nongnu.org
> Signed-off-by: Markus Armbruster 
> ---

Reviewed-by: Peter Maydell 

thanks
-- PMM

[PATCH v2 06/13] hw/arm/mcimx6ul-evk: Replace drive_get_next() by drive_get()

[Markus Armbruster]

drive_get_next() is basically a bad idea.  It returns the "next" block
backend of a certain interface type.  "Next" means bus=0,unit=N, where
subsequent calls count N up from zero, per interface type.

This lets you define unit numbers implicitly by execution order.  If the
order changes, or new calls appear "in the middle", unit numbers change.
ABI break.  Hard to spot in review.

Machine "mcimx6ul-evk" connects backends with drive_get_next() in a
counting loop.  Change it to use drive_get() directly.  This makes the
unit numbers explicit in the code.

Cc: Peter Maydell 
Cc: Jean-Christophe Dubois 
Cc: qemu-...@nongnu.org
Signed-off-by: Markus Armbruster 
---
 hw/arm/mcimx6ul-evk.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/arm/mcimx6ul-evk.c b/hw/arm/mcimx6ul-evk.c
index 77fae874b1..28b4886f48 100644
--- a/hw/arm/mcimx6ul-evk.c
+++ b/hw/arm/mcimx6ul-evk.c
@@ -52,7 +52,7 @@ static void mcimx6ul_evk_init(MachineState *machine)
 DriveInfo *di;
 BlockBackend *blk;
 
-di = drive_get_next(IF_SD);
+di = drive_get(IF_SD, 0, i);
 blk = di ? blk_by_legacy_dinfo(di) : NULL;
 bus = qdev_get_child_bus(DEVICE(>usdhc[i]), "sd-bus");
 carddev = qdev_new(TYPE_SD_CARD);
-- 
2.31.1