Friday, April 25, 2014, 11:51:53 PM, you wrote: > 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? Hi Ezequiel, Just tested with your v2 patch for a while and haven't seen the warning again :-) I don't remember for certain if it gave any serious issues .. since i have been running with you v1 patch now for a while and it's on a test machine i use infrequently. -- Sander >> 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 -- 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
