Re: [PATCH] usbnet: ax88179_178a: Add support for writing the EEPROM

On Wed, 24 Aug 2016 16:30:39 +0200
Oliver Neukum [off-list ref] wrote:

On Wed, 2016-08-24 at 15:52 +0200, Alban Bedel wrote:

quoted

Implement the .set_eeprom callback to allow setting the MAC address
as well as a few other parameters. Note that the EEPROM must have a
correct PID/VID checksum set otherwise the SROM is used and reads
return the SROM content.

Signed-off-by: Alban Bedel <redacted>
---
 drivers/net/usb/ax88179_178a.c | 57
++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/drivers/net/usb/ax88179_178a.c

b/drivers/net/usb/ax88179_178a.c
index e6338c16081a..e6a986303dad 100644

--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c

@@ -28,6 +28,7 @@
 
 #define AX88179_PHY_ID                         0x03
 #define AX_EEPROM_LEN                          0x100
+#define AX_EEPROM_BLOCK                                0x40u
 #define AX88179_EEPROM_MAGIC                   0x17900b95
 #define AX_MCAST_FLTSIZE                       8
 #define AX_MAX_MCAST                           64

@@ -43,6 +44,7 @@
 #define AX_ACCESS_PHY                          0x02
 #define AX_ACCESS_EEPROM                       0x04
 #define AX_ACCESS_EFUS                         0x05
+#define AX_RELOAD_EEPROM                       0x06
 #define AX_PAUSE_WATERLVL_HIGH                 0x54
 #define AX_PAUSE_WATERLVL_LOW                  0x55
 

@@ -620,6 +622,60 @@ ax88179_get_eeprom(struct net_device *net, struct

ethtool_eeprom *eeprom,
        return 0;
 }
 
+static int
+ax88179_set_eeprom(struct net_device *net, struct ethtool_eeprom
*eeprom,
+                  u8 *data)
+{
+       struct usbnet *dev = netdev_priv(net);
+       unsigned int offset = eeprom->offset;
+       unsigned int len = eeprom->len;
+       int i, err = 0;
+       u8 *block;
+
+       /* The EEPROM data must be aligned on blocks of 64 bytes */
+       if ((offset % AX_EEPROM_BLOCK) || (len % AX_EEPROM_BLOCK)) {
+               offset = eeprom->offset / AX_EEPROM_BLOCK *
AX_EEPROM_BLOCK;
+               len = eeprom->len + eeprom->offset - offset;
+               len = DIV_ROUND_UP(len, AX_EEPROM_BLOCK) *
AX_EEPROM_BLOCK;
+
+               block = kmalloc(len, GFP_KERNEL);
+               if (!block)
+                       return -ENOMEM;
+
+               /* Copy the current data, we could skip some but KISS
*/
+               for (i = 0; i < len; i += AX_EEPROM_BLOCK) {
+                       err = __ax88179_read_cmd(dev,
AX_ACCESS_EEPROM,
+                                                (offset + i) >> 1,
+                                                AX_EEPROM_BLOCK >> 1,
+                                                AX_EEPROM_BLOCK,
+                                                &block[i], 0);
+                       if (err < 0) {
+                               kfree(block);
+                               return err;
+                       }
+               }
+               memcpy(block + eeprom->offset - offset, data,
eeprom->len);
+       } else {
+               block = data;
+       }
+
+       for (i = 0; err >= 0 && i < len; i += AX_EEPROM_BLOCK) {
+               err = ax88179_write_cmd(dev, AX_ACCESS_EEPROM,
+                                       (offset + i) >> 1,
+                                       AX_EEPROM_BLOCK >> 1,
+                                       AX_EEPROM_BLOCK, &block[i]);
+       }
+
+       if (block != data)
+               kfree(block);  

And if block == dta, what frees the memory?

In this case this function didn't allocate any memory, so there is
nothing to free.

Alban