Re: [PATCH 5/5] net/xgene: fix error handling during reset

[David Miller]

From: Arnd Bergmann <arnd@xxxxxxxx>
Date: Fri, 26 Aug 2016 17:25:46 +0200

> The newly added reset logic uses helper functions for the MMIO that
> may fail. However, when the read operation fails, we end up writing
> back uninitialized data to the register, as gcc warns:
> 
> drivers/net/ethernet/apm/xgene/xgene_enet_xgmac.c: In function 'xgene_enet_link_state':
> drivers/net/ethernet/apm/xgene/xgene_enet_xgmac.c:213:2: error: 'data' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> drivers/net/ethernet/apm/xgene/xgene_enet_xgmac.c:209:6: note: 'data' was declared here
>   u32 data;
> 
> We already print a warning to the console log if that happens,
> the best alternative that I can see is skip the rest of the reset
> sequence if the register value cannot be read: Most likely the
> write would fail as well, and if it succeeded, worse things could
> happen.
> 
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> Fixes: 3eb7cb9dc946 ("drivers: net: xgene: XFI PCS reset when link is down")

Applied.