Re: [PATCH 1/3] Blackfin ethernet driver: on chip ethernet MAC controller driver

On Saturday 14 July 2007 21:49:21 Mike Frysinger wrote:

On 7/14/07, Michael Buesch [off-list ref] wrote:

quoted

On Saturday 14 July 2007 20:49:53 Bryan Wu wrote:

quoted

+static int __init bf537mac_probe(struct net_device *dev)
+{
+     struct bf537mac_local *lp = netdev_priv(dev);
+     int retval;
+
+     /* Grab the MAC address in the MAC */
+     *(u32 *) (&(dev->dev_addr[0])) = bfin_read_EMAC_ADDRLO();
+     *(u16 *) (&(dev->dev_addr[4])) = (u16) bfin_read_EMAC_ADDRHI();

Endianess broken.

quoted

+struct dma_config_reg {
+     unsigned short b_DMA_EN:1;  /* Bit 0 : DMA Enable */
+     unsigned short b_WNR:1;     /* Bit 1 : DMA Direction */
+     unsigned short b_WDSIZE:2;  /* Bit 2 & 3 : DMA Tranfer Word size */
+     unsigned short b_DMA2D:1;   /* Bit 4 : DMA Mode 2D or 1D */
+     unsigned short b_RESTART:1; /* Bit 5 : Retain the FIFO */
+     unsigned short b_DI_SEL:1;  /* Bit 6 : Data Interrupt Timing Select */
+     unsigned short b_DI_EN:1;   /* Bit 7 : Data Interrupt Enable */
+     unsigned short b_NDSIZE:4;  /* Bit 8 to 11 : Flex descriptor Size */
+     unsigned short b_FLOW:3;    /* Bit 12 to 14 : FLOW */
+};

This is most likely not endianess safe.

do we really need to care about this ?  this is a driver for a MAC
which can only be found on Blackfin processors and Blackfin itself is
only little endian.

Well, this bitfield _might_ be OK (although I don't like bitfields
at all), but the above pointer casting stuff should really use
leXX_to_cpu. It's so easy to use and it is easier to read and
maintain the code afterwards.
If the bitfield stays, a comment must be added.

-- 
Greetings Michael.