[PATCH v2 17/22] usb: serial: ti_usb_3410_5052: Fix firmware downloading

Mathieu OTHACEHE
2016-07-26T18:06:03Z

The buffer used to store firmware is allocated to maximum firmware
size (TI_FIRMWARE_BUF_SIZE) + header size.
This buffer is filled with requested firmware (fw_p->size) and padded
with 0xff bytes. The header is written over the 3 first bytes of the
buffer (overwritting the 3 first bytes of the requested firmware)

Then, ti_do_download function is called to send only the first
fw_p->size bytes from the buffer to the device.
The rest of the buffer is never used.

So it is sufficient to allocate a buffer of fw_p->size bytes to store
only the requested firmware. There is no need to do any padding.

This patch also move firmware buffer manipulation to ti_do_download
function.

Signed-off-by: Mathieu OTHACEHE <m.othacehe@gmail.com>
---
drivers/usb/serial/ti_usb_3410_5052.c | 61 +++++++++++++++++++----------------
1 file changed, 33 insertions(+), 28 deletions(-)

diff --git a/drivers/usb/serial/ti_usb_3410_5052.c b/drivers/usb/serial/ti_usb_3410_5052.c
index 472971b..b46a511 100644
--- a/drivers/usb/serial/ti_usb_3410_5052.c
+++ b/drivers/usb/serial/ti_usb_3410_5052.c
@@ -1639,46 +1639,65 @@ static int ti_write_byte(struct usb_serial_port *port, u32 addr,
return status;
}

-static int ti_do_download(struct usb_device *dev, int pipe,
- u8 *buffer, int size)
+static int ti_do_download(struct usb_serial *serial,
+ const struct firmware *fw_p)
{
int pos;
u8 cs = 0;
int done;
+ struct usb_device *dev = serial->dev;
struct ti_firmware_header *header;
int status = 0;
+ u8 *buffer;
+ int buffer_size;
int len;
+ unsigned int pipe;
+
+ pipe = usb_sndbulkpipe(dev, serial->port[0]->bulk_out_endpointAddress);
+
+ buffer_size = fw_p->size;
+ buffer = kmalloc(buffer_size, GFP_KERNEL);
+ if (!buffer)
+ return -ENOMEM;

- for (pos = sizeof(struct ti_firmware_header); pos < size; pos++)
+ memcpy(buffer, fw_p->data, fw_p->size);
+
+ for (pos = sizeof(*header); pos < buffer_size; pos++)
cs = (u8)(cs + buffer[pos]);

header = (struct ti_firmware_header *)buffer;
- header->wLength = cpu_to_le16(size - sizeof(*header));
+ header->wLength = cpu_to_le16(buffer_size - sizeof(*header));
header->bCheckSum = cs;

dev_dbg(&dev->dev, "%s - downloading firmware\n", __func__);
- for (pos = 0; pos < size; pos += done) {
- len = min(size - pos, TI_DOWNLOAD_MAX_PACKET_SIZE);
+ for (pos = 0; pos < buffer_size; pos += done) {
+ len = min(buffer_size - pos, TI_DOWNLOAD_MAX_PACKET_SIZE);
status = usb_bulk_msg(dev, pipe, buffer + pos, len, &done,
TI_DOWNLOAD_TIMEOUT);
if (status)
break;
}
- return status;
+
+ kfree(buffer);
+
+ if (status) {
+ dev_err(&dev->dev, "failed to download firmware: %d\n", status);
+ return status;
+ }
+
+ dev_dbg(&dev->dev, "%s - download successful\n", __func__);
+
+ return 0;
}

static int ti_download_firmware(struct usb_serial *serial)
{
int status;
- int buffer_size;
- u8 *buffer;
struct usb_device *dev = serial->dev;
struct ti_device *tdev = usb_get_serial_data(serial);
- unsigned int pipe;
const struct firmware *fw_p;
char buf[32];

- pipe = usb_sndbulkpipe(dev, serial->port[0]->bulk_out_endpointAddress);

if (le16_to_cpu(dev->descriptor.idVendor) == MXU1_VENDOR_ID) {
snprintf(buf,
@@ -1733,30 +1752,16 @@ check_firmware:
dev_err(&dev->dev, "%s - firmware not found\n", __func__);
return -ENOENT;
}
+
if (fw_p->size > TI_FIRMWARE_BUF_SIZE) {
dev_err(&dev->dev, "%s - firmware too large %zu\n", __func__, fw_p->size);
release_firmware(fw_p);
return -ENOENT;
}

- buffer_size = TI_FIRMWARE_BUF_SIZE + sizeof(struct ti_firmware_header);
- buffer = kmalloc(buffer_size, GFP_KERNEL);
- if (buffer) {
- memcpy(buffer, fw_p->data, fw_p->size);
- memset(buffer + fw_p->size, 0xff, buffer_size - fw_p->size);
- status = ti_do_download(dev, pipe, buffer, fw_p->size);
- kfree(buffer);
- } else {
- status = -ENOMEM;
- }
- release_firmware(fw_p);
- if (status) {
- dev_err(&dev->dev, "%s - error downloading firmware, %d\n",
- __func__, status);
- return status;
- }
+ ti_do_download(serial, fw_p);

- dev_dbg(&dev->dev, "%s - download successful\n", __func__);
+ release_firmware(fw_p);

return 0;
}
--
2.9.0