From 655e5ff7d64930835bf42a3be85b8eec0e40ddbd Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 2 Feb 2017 12:53:04 -0200 Subject: [PATCH] pvrusb2: reduce stack usage pvr2_eeprom_analyze() commit 6830733d53a4517588e56227b9c8538633f0c496 upstream. The driver uses a relatively large data structure on the stack, which showed up on my radar as we get a warning with the "latent entropy" GCC plugin: drivers/media/usb/pvrusb2/pvrusb2-eeprom.c:153:1: error: the frame size of 1376 bytes is larger than 1152 bytes [-Werror=frame-larger-than=] The warning is usually hidden as we raise the warning limit to 2048 when the plugin is enabled, but I'd like to lower that again in the future, and making this function smaller helps to do that without build regressions. Further analysis shows that putting an 'i2c_client' structure on the stack is not really supported, as the embedded 'struct device' is not initialized here, and we are only saved by the fact that the function that is called here does not use the pointer at all. Fixes: d855497edbfb ("V4L/DVB (4228a): pvrusb2 to kernel 2.6.18") Signed-off-by: Arnd Bergmann Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Willy Tarreau --- drivers/media/usb/pvrusb2/pvrusb2-eeprom.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) diff --git a/drivers/media/usb/pvrusb2/pvrusb2-eeprom.c b/drivers/media/usb/pvrusb2/pvrusb2-eeprom.c index 9515f3a68f8f..122815e1cb65 100644 --- a/drivers/media/usb/pvrusb2/pvrusb2-eeprom.c +++ b/drivers/media/usb/pvrusb2/pvrusb2-eeprom.c @@ -123,15 +123,10 @@ int pvr2_eeprom_analyze(struct pvr2_hdw *hdw) memset(&tvdata,0,sizeof(tvdata)); eeprom = pvr2_eeprom_fetch(hdw); - if (!eeprom) return -EINVAL; - - { - struct i2c_client fake_client; - /* Newer version expects a useless client interface */ - fake_client.addr = hdw->eeprom_addr; - fake_client.adapter = &hdw->i2c_adap; - tveeprom_hauppauge_analog(&fake_client,&tvdata,eeprom); - } + if (!eeprom) + return -EINVAL; + + tveeprom_hauppauge_analog(NULL, &tvdata, eeprom); trace_eeprom("eeprom assumed v4l tveeprom module"); trace_eeprom("eeprom direct call results:"); -- 2.20.1