On Apr 17, Ezequiel Garcia wrote: > Currently stk1160_read_reg() uses a stack-allocated char to get the > read control value. This is wrong because usb_control_msg() requires > a kmalloc-ed buffer. > > This commit fixes such issue by kmalloc'ating a 1-byte buffer to receive > the read value. > > While here, let's remove the urb_buf array which was meant for a similar > purpose, but never really used. > > Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > Reported-by: Sander Eikelenboom <linux@xxxxxxxxxxxxxx> Ouch, I forgot to Cc Sander! Sander, Here's the patch: https://patchwork.linuxtv.org/patch/23660/ Maybe you can give it a ride and confirm it fixes the warning over there? Also, have you observed any serious issues caused by this or just the DMA API debug warning? > Signed-off-by: Ezequiel Garcia <ezequiel.garcia@xxxxxxxxxxxxxxxxxx> > --- > drivers/media/usb/stk1160/stk1160-core.c | 10 +++++++++- > drivers/media/usb/stk1160/stk1160.h | 1 - > 2 files changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/usb/stk1160/stk1160-core.c b/drivers/media/usb/stk1160/stk1160-core.c > index 34a26e0..03504dc 100644 > --- a/drivers/media/usb/stk1160/stk1160-core.c > +++ b/drivers/media/usb/stk1160/stk1160-core.c > @@ -67,17 +67,25 @@ int stk1160_read_reg(struct stk1160 *dev, u16 reg, u8 *value) > { > int ret; > int pipe = usb_rcvctrlpipe(dev->udev, 0); > + u8 *buf; > > *value = 0; > + > + buf = kmalloc(sizeof(u8), GFP_KERNEL); > + if (!buf) > + return -ENOMEM; > ret = usb_control_msg(dev->udev, pipe, 0x00, > USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE, > - 0x00, reg, value, sizeof(u8), HZ); > + 0x00, reg, buf, sizeof(u8), HZ); > if (ret < 0) { > stk1160_err("read failed on reg 0x%x (%d)\n", > reg, ret); > + kfree(buf); > return ret; > } > > + *value = *buf; > + kfree(buf); > return 0; > } > > diff --git a/drivers/media/usb/stk1160/stk1160.h b/drivers/media/usb/stk1160/stk1160.h > index 05b05b1..abdea48 100644 > --- a/drivers/media/usb/stk1160/stk1160.h > +++ b/drivers/media/usb/stk1160/stk1160.h > @@ -143,7 +143,6 @@ struct stk1160 { > int num_alt; > > struct stk1160_isoc_ctl isoc_ctl; > - char urb_buf[255]; /* urb control msg buffer */ > > /* frame properties */ > int width; /* current frame width */ > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-media" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Ezequiel García, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
