On Wed, Sep 09, 2015 at 05:16:22PM +0800, Yuantian.Tang@freescale.com wrote:

From: Tang Yuantian <redacted>

kbuild test robot reports the warnings:
drivers/ata/ahci_qoriq.c: In function 'ahci_qoriq_hardreset':

quoted

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include/asm-generic/io.h:163:2: warning: 'px_is' may be used
uninitialized in this function [-Wuninitialized]

drivers/ata/ahci_qoriq.c:70:14: note: 'px_is' was declared here

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include/asm-generic/io.h:163:2: warning: 'px_cmd' may be used
uninitialized in this function [-Wuninitialized]

drivers/ata/ahci_qoriq.c:70:6: note: 'px_cmd' was declared here

This patch fixed it by assigning 0 to px_is and px_cmd variables.
This patch also remove line 'struct ccsr_ahci *reg_base' which is
not referred by any other codes and thus a dead one.

Hmm... I think the problem here is that the complier can't know
whether qoriq_priv->type would change across intervening function
calls.  Maybe a better solution is caching the type in a local
variable so that the compiler can tell that those two tests will
always move together?  It generally isn't a good idea to clear
variables unnecessarily as that can hide actual bugs that compiler can
detect.

Thanks.

-- 
tejun