Re: [PATCH] dec: tulip: de4x5: Replace mdelay with usleep_range in de4x5_hw_init

[kbuild test robot]

Hi Jia-Ju,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on net-next/master]
[also build test ERROR on v4.16 next-20180411]
[if your patch is applied to the wrong git tree, please drop us a note to help 
improve the system]

url:
https://github.com/0day-ci/linux/commits/Jia-Ju-Bai/dec-tulip-de4x5-Replace-mdelay-with-usleep_range-in-de4x5_hw_init/20180411-222527
config: i386-randconfig-x015-201814 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=i386 

All errors (new ones prefixed by >>):

   drivers/net//ethernet/dec/tulip/de4x5.c: In function 'de4x5_hw_init':
>> drivers/net//ethernet/dec/tulip/de4x5.c:1110:5: error: implicit declaration 
>> of function 'usleep'; did you mean 'ssleep'? 
>> [-Werror=implicit-function-declaration]
usleep(1, 11000);
^~
ssleep
   cc1: some warnings being treated as errors

vim +1110 drivers/net//ethernet/dec/tulip/de4x5.c

  1091  
  1092  
  1093  static int
  1094  de4x5_hw_init(struct net_device *dev, u_long iobase, struct device 
*gendev)
  1095  {
  1096  char name[DE4X5_NAME_LENGTH + 1];
  1097  struct de4x5_private *lp = netdev_priv(dev);
  1098  struct pci_dev *pdev = NULL;
  1099  int i, status=0;
  1100  
  1101  dev_set_drvdata(gendev, dev);
  1102  
  1103  /* Ensure we're not sleeping */
  1104  if (lp->bus == EISA) {
  1105  outb(WAKEUP, PCI_CFPM);
  1106  } else {
  1107  pdev = to_pci_dev (gendev);
  1108  pci_write_config_byte(pdev, PCI_CFDA_PSM, WAKEUP);
  1109  }
> 1110  usleep(1, 11000);
    
  1112  RESET_DE4X5;
  1113  
  1114  if ((inl(DE4X5_STS) & (STS_TS | STS_RS)) != 0) {
  1115  return -ENXIO;   /* Hardware could not 
reset */
  1116  }
  1117  
  1118  /*
  1119  ** Now find out what kind of DC21040/DC21041/DC21140 board we have.
  1120  */
  1121  lp->useSROM = false;
  1122  if (lp->bus == PCI) {
  1123  PCI_signature(name, lp);
  1124  } else {
  1125  EISA_signature(name, gendev);
  1126  }
  1127  
  1128  if (*name == '\0') { /* Not found a board 
signature */
  1129  return -ENXIO;
  1130  }
  1131  
  1132  dev->base_addr = iobase;
  1133  printk ("%s: %s at 0x%04lx", dev_name(gendev), name, iobase);
  1134  
  1135  status = get_hw_addr(dev);
  1136  printk(", h/w address %pM\n", dev->dev_addr);
  1137  
  1138  if (status != 0) {
  1139  printk("  which has an Ethernet PROM CRC error.\n");
  1140  return -ENXIO;
  1141  } else {
  1142  skb_queue_head_init(&lp->cache.queue);
  1143  lp->cache.gepc = GEP_INIT;
  1144  lp->asBit = GEP_SLNK;
  1145  lp->asPolarity = GEP_SLNK;
  1146  lp->asBitValid = ~0;
  1147  lp->timeout = -1;
  1148  lp->gendev = gendev;
  1149  spin_lock_init(&lp->lock);
  1150  timer_setup(&lp->timer, de4x5_ast, 0);
  1151  de4x5_parse_params(dev);
  1152  
  1153  /*
  1154  ** Choose correct autosensing in case someone messed up
  1155  */
  1156  lp->autosense = lp->params.autosense;
  1157  if (lp->chipset != DC21140) {
  1158  if ((lp->chipset==DC21040) && (lp->params.autosense&TP_NW)) 
{
  1159  lp->params.autosense = TP;
  1160  }
  1161  if ((lp->chipset==DC21041) && 
(lp->params.autosense&BNC_AUI)) {
  1162  lp->params.autosense = BNC;
  1163  }
  1164  }
  1165  lp->fdx = lp->params.fdx;
  1166  sprintf(lp->adapter_name,"%s (%s)", name, dev_name(gendev));
  1167  
  1168  lp->dma_size = (NUM_RX_DESC + NUM_TX_DESC) * sizeof(struct 
de4x5_desc);
  1169  #if defined(__alpha__) || defined(__powerpc__) || defined(CONFIG_SPARC) 
|| defined(DE4X5_DO_MEMCPY)
  1170  lp->dma_size += RX_BUFF_SZ * NUM_RX_DESC + DE4X5_ALIGN;
  1171  #endif
  1172  lp->rx_ring = dma_alloc_coherent(gendev, lp->dma_size,
  1173   &lp->dma_rings, GFP_ATOMIC);
  1174  if (lp->rx_ring == NULL) {
  1175  return -ENOMEM;
  1176  }
  1177  
  1178  lp->tx_ring = lp->rx_ring + NUM_RX_DESC;
  1179  
  1180  /*
  1181  ** Set up the RX descriptor ring (Intels)
  1182  ** Allocate contiguous receive buffers, long word aligned 
(Alphas)
  1183  */
  1184  #if !defined(__alpha__) && !defined(__powerpc__) && 
!defined(CONFIG_SPARC) && !defined(DE4X5_DO_MEMCPY)
  1185  for (i=0; irx_ring[i].status = 0;
  1187  lp->rx_ring[i].des1 = cpu_to_le32(RX_BUFF_SZ);
  1188  lp->rx_ring[i].buf = 0;
  1189  lp->rx_ring[i].next = 0;
  1190  lp->rx_skb[i] = (struct sk_buff

[PATCH] dec: tulip: de4x5: Replace mdelay with usleep_range in de4x5_hw_init

[Jia-Ju Bai]

de4x5_hw_init() is never called in atomic context.

de4x5_hw_init() is only called by de4x5_pci_probe(), which is only 
set as ".probe" in struct pci_driver.

Despite never getting called from atomic context, de4x5_hw_init() 
calls mdelay() to busily wait.
This is not necessary and can be replaced with usleep_range() to 
avoid busy waiting.

This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.

Signed-off-by: Jia-Ju Bai 
---
 drivers/net/ethernet/dec/tulip/de4x5.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/dec/tulip/de4x5.c 
b/drivers/net/ethernet/dec/tulip/de4x5.c
index 0affee9..3fb0119 100644
--- a/drivers/net/ethernet/dec/tulip/de4x5.c
+++ b/drivers/net/ethernet/dec/tulip/de4x5.c
@@ -1107,7 +1107,7 @@ static int (*dc_infoblock[])(struct net_device *dev, 
u_char, u_char *) = {
pdev = to_pci_dev (gendev);
pci_write_config_byte(pdev, PCI_CFDA_PSM, WAKEUP);
 }
-mdelay(10);
+usleep(1, 11000);
 
 RESET_DE4X5;
 
-- 
1.9.1