Linux下FL2440 2.6.28 SD卡驱动BUG解决

FL2440的2.6.28的内核，SD卡驱动默认是有问题的，在

linux-2.6.28.7\drivers\mmc\host目录的s3cmci.c文件

的do_pio_write函数中做如下修改：

static void do_pio_write(struct s3cmci_host *host)
{
 void __iomem *to_ptr;
 int res;
 u32 fifo;
 u32 *ptr; 
 to_ptr = host->base + host->sdidata;
 //while ((fifo = fifo_free(host)))
 while ((fifo = fifo_free(host))>3) //lqm changed from feiling FAE.11-01-19
 {
  if (!host->pio_bytes)  
  {
   res = get_data_buffer(host, &host->pio_bytes,&host->pio_ptr);
   if (res)
   {   
    dbg(host, dbg_pio,"pio_write(): complete (no more data).\n"); 

host->pio_active =XFER_NONE;
    return;  
   }
   dbg(host, dbg_pio,"pio_write(): new source: [%i]@[%p]\n",host->pio_bytes,

host->pio_ptr);
  }
  /* If we have reached the end of the block, we have to  
   * write exactly the remaining number of bytes.  If we 
   * in the middle of the block, we have to write full 
   * words, so round down to an even multiple of 4. */
  if (fifo >=host->pio_bytes)
   fifo = host->pio_bytes; 
  else
   fifo -= fifo & 3;
  host->pio_bytes -= fifo;
  host->pio_count += fifo; 
  fifo = (fifo + 3) >> 2;
  ptr = host->pio_ptr; 
  while (fifo--)
   writel(*ptr++, to_ptr); 
  host->pio_ptr = ptr;
 }
 enable_imask(host, S3C2410_SDIIMSK_TXFIFOHALF);
}

经测试，1G，2G的SD卡可稳定运行。