When CONFIG_PCI is disabled, pci_read_config_byte() may not update its result, as indicated by this warning:
drivers/idle/i7300_idle.c: In function ‘i7300_idle_notifier’: drivers/idle/i7300_idle.c:423:141: warning: ‘got_ctl’ may be used uninitialized in this function [-Wmaybe-uninitialized] drivers/idle/i7300_idle.c:415:5: note: ‘got_ctl’ was declared here We know the function is never called if CONFIG_PCI is not set, so this is harmless, but we can avoid the problem by checking the return value of the config space accessor before using the result. Signed-off-by: Arnd Bergmann <[email protected]> --- drivers/idle/i7300_idle.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/idle/i7300_idle.c b/drivers/idle/i7300_idle.c index ffeebc7e9f1c..9a104e558c77 100644 --- a/drivers/idle/i7300_idle.c +++ b/drivers/idle/i7300_idle.c @@ -347,6 +347,7 @@ static int i7300_idle_thrt_save(void) { u32 new_mc_val; u8 gblactlm; + int ret; pci_read_config_byte(fbd_dev, DIMM_THRTCTL, &i7300_idle_thrtctl_saved); pci_read_config_byte(fbd_dev, DIMM_THRTLOW, &i7300_idle_thrtlow_saved); @@ -364,7 +365,9 @@ static int i7300_idle_thrt_save(void) * unlimited-activations while in open-loop throttling (i.e., when * Global Activation Throttle Limit is zero). */ - pci_read_config_byte(fbd_dev, DIMM_GBLACT, &gblactlm); + ret = pci_read_config_byte(fbd_dev, DIMM_GBLACT, &gblactlm); + if (ret) + return ret; dprintk("thrtctl_saved = 0x%02x, thrtlow_saved = 0x%02x\n", i7300_idle_thrtctl_saved, i7300_idle_thrtlow_saved); @@ -413,14 +416,16 @@ static void i7300_idle_stop(void) { u8 new_ctl; u8 got_ctl; + int ret; new_ctl = i7300_idle_thrtctl_saved & ~DIMM_THRTCTL_THRMHUNT; pci_write_config_byte(fbd_dev, DIMM_THRTCTL, new_ctl); pci_write_config_byte(fbd_dev, DIMM_THRTLOW, i7300_idle_thrtlow_saved); pci_write_config_byte(fbd_dev, DIMM_THRTCTL, i7300_idle_thrtctl_saved); - pci_read_config_byte(fbd_dev, DIMM_THRTCTL, &got_ctl); - WARN_ON_ONCE(got_ctl != i7300_idle_thrtctl_saved); + ret = pci_read_config_byte(fbd_dev, DIMM_THRTCTL, &got_ctl); + + WARN_ON_ONCE(ret || (got_ctl != i7300_idle_thrtctl_saved)); } -- 2.9.0
