| Message ID | 20210126183403.911653-8-anant.thazhemadam@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | drivers: usb: misc: update to use usb_control_msg_{send|recv}() API | expand |
On Wed, Jan 27, 2021 at 12:03:58AM +0530, Anant Thazhemadam wrote: > The newer usb_control_msg_{send|recv}() API are an improvement on the > existing usb_control_msg() as it ensures that a short read/write is treated > as an error, data can be used off the stack, and raw usb pipes need not be > created in the calling functions. > For this reason, the instances of usb_control_msg() have been replaced with > usb_control_msg_send(), and return value checking has also been > appropriately enforced. > > Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com> > --- > drivers/usb/misc/isight_firmware.c | 30 +++++++++++++----------------- > 1 file changed, 13 insertions(+), 17 deletions(-) > > diff --git a/drivers/usb/misc/isight_firmware.c b/drivers/usb/misc/isight_firmware.c > index 4d30095d6ad2..1bd14a431f6c 100644 > --- a/drivers/usb/misc/isight_firmware.c > +++ b/drivers/usb/misc/isight_firmware.c > @@ -37,13 +37,10 @@ static int isight_firmware_load(struct usb_interface *intf, > struct usb_device *dev = interface_to_usbdev(intf); > int llen, len, req, ret = 0; > const struct firmware *firmware; > - unsigned char *buf = kmalloc(50, GFP_KERNEL); > + unsigned char buf[50]; This buffer is probably large enough to not want to have it allocated on the stack. > unsigned char data[4]; > const u8 *ptr; > > - if (!buf) > - return -ENOMEM; > - > if (request_firmware(&firmware, "isight.fw", &dev->dev) != 0) { > printk(KERN_ERR "Unable to load isight firmware\n"); > ret = -ENODEV; > @@ -53,11 +50,11 @@ static int isight_firmware_load(struct usb_interface *intf, > ptr = firmware->data; > > buf[0] = 0x01; > - if (usb_control_msg > - (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, buf, 1, > - 300) != 1) { > + ret = usb_control_msg_send(dev, 0, 0xa0, 0x40, 0xe600, > + 0, &buf, 1, 300, GFP_KERNEL); > + if (ret != 0) { > printk(KERN_ERR > - "Failed to initialise isight firmware loader\n"); > + "Failed to initialise isight firmware loader\n"); > ret = -ENODEV; > goto out; > } > @@ -82,15 +79,15 @@ static int isight_firmware_load(struct usb_interface *intf, > ret = -ENODEV; > goto out; > } > - memcpy(buf, ptr, llen); > + memcpy(&buf, ptr, llen); > > ptr += llen; > > - if (usb_control_msg > - (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, req, 0, > - buf, llen, 300) != llen) { > + ret = usb_control_msg_send(dev, 0, 0xa0, 0x40, req, 0, > + &buf, llen, 300, GFP_KERNEL); > + if (ret != 0) { > printk(KERN_ERR > - "Failed to load isight firmware\n"); > + "Failed to load isight firmware\n"); > ret = -ENODEV; > goto out; > } And here the same buffer is reused for each block of data, while the new helpers would add an allocation and a redundant memcpy() of the data (which was just copied a few lines above) for each iteration. So I suggest you drop this one as well. Johan
diff --git a/drivers/usb/misc/isight_firmware.c b/drivers/usb/misc/isight_firmware.c index 4d30095d6ad2..1bd14a431f6c 100644 --- a/drivers/usb/misc/isight_firmware.c +++ b/drivers/usb/misc/isight_firmware.c @@ -37,13 +37,10 @@ static int isight_firmware_load(struct usb_interface *intf, struct usb_device *dev = interface_to_usbdev(intf); int llen, len, req, ret = 0; const struct firmware *firmware; - unsigned char *buf = kmalloc(50, GFP_KERNEL); + unsigned char buf[50]; unsigned char data[4]; const u8 *ptr; - if (!buf) - return -ENOMEM; - if (request_firmware(&firmware, "isight.fw", &dev->dev) != 0) { printk(KERN_ERR "Unable to load isight firmware\n"); ret = -ENODEV; @@ -53,11 +50,11 @@ static int isight_firmware_load(struct usb_interface *intf, ptr = firmware->data; buf[0] = 0x01; - if (usb_control_msg - (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, buf, 1, - 300) != 1) { + ret = usb_control_msg_send(dev, 0, 0xa0, 0x40, 0xe600, + 0, &buf, 1, 300, GFP_KERNEL); + if (ret != 0) { printk(KERN_ERR - "Failed to initialise isight firmware loader\n"); + "Failed to initialise isight firmware loader\n"); ret = -ENODEV; goto out; } @@ -82,15 +79,15 @@ static int isight_firmware_load(struct usb_interface *intf, ret = -ENODEV; goto out; } - memcpy(buf, ptr, llen); + memcpy(&buf, ptr, llen); ptr += llen; - if (usb_control_msg - (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, req, 0, - buf, llen, 300) != llen) { + ret = usb_control_msg_send(dev, 0, 0xa0, 0x40, req, 0, + &buf, llen, 300, GFP_KERNEL); + if (ret != 0) { printk(KERN_ERR - "Failed to load isight firmware\n"); + "Failed to load isight firmware\n"); ret = -ENODEV; goto out; } @@ -99,15 +96,14 @@ static int isight_firmware_load(struct usb_interface *intf, } buf[0] = 0x00; - if (usb_control_msg - (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, buf, 1, - 300) != 1) { + ret = usb_control_msg_send(dev, 0, 0xa0, 0x40, 0xe600, + 0, &buf, 1, 300, GFP_KERNEL); + if (ret != 0) { printk(KERN_ERR "isight firmware loading completion failed\n"); ret = -ENODEV; } out: - kfree(buf); release_firmware(firmware); return ret; }
The newer usb_control_msg_{send|recv}() API are an improvement on the existing usb_control_msg() as it ensures that a short read/write is treated as an error, data can be used off the stack, and raw usb pipes need not be created in the calling functions. For this reason, the instances of usb_control_msg() have been replaced with usb_control_msg_send(), and return value checking has also been appropriately enforced. Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com> --- drivers/usb/misc/isight_firmware.c | 30 +++++++++++++----------------- 1 file changed, 13 insertions(+), 17 deletions(-)