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* re: stmmac: add descriptors function for GMAC 4.xx
@ 2016-04-04 20:46 Dan Carpenter
  2016-04-05  9:24 ` Alexandre Torgue
  0 siblings, 1 reply; 2+ messages in thread
From: Dan Carpenter @ 2016-04-04 20:46 UTC (permalink / raw)
  To: kernel-janitors

Hello Alexandre TORGUE,

The patch 753a71090f33: "stmmac: add descriptors function for GMAC
4.xx" from Apr 1, 2016, leads to the following static checker warning:

	drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c:261 dwmac4_rd_prepare_tx_desc()
	warn: odd binop '0x4000 & 0x3fff'

drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
   251  static void dwmac4_rd_prepare_tx_desc(struct dma_desc *p, int is_fs, int len,
   252                                        bool csum_flag, int mode, bool tx_own,
   253                                        bool ls)
   254  {
   255          unsigned int tdes3 = p->des3;
   256  
   257          if (unlikely(len > BUF_SIZE_16KiB)) {
   258                  p->des2 |= (((len - BUF_SIZE_16KiB) <<
   259                               TDES2_BUFFER2_SIZE_MASK_SHIFT)
   260                              & TDES2_BUFFER2_SIZE_MASK)
   261                              | (BUF_SIZE_16KiB & TDES2_BUFFER1_SIZE_MASK);
                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Should this be "len & TDES2_BUFFER1_SIZE_MASK" or are you rounding down
the length deliberately?

   262          } else {
   263                  p->des2 |= (len & TDES2_BUFFER1_SIZE_MASK);
   264          }
   265  
   266          if (is_fs)
   267                  tdes3 |= TDES3_FIRST_DESCRIPTOR;
   268          else
   269                  tdes3 &= ~TDES3_FIRST_DESCRIPTOR;
   270  

regards,
dan carpenter

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: stmmac: add descriptors function for GMAC 4.xx
  2016-04-04 20:46 stmmac: add descriptors function for GMAC 4.xx Dan Carpenter
@ 2016-04-05  9:24 ` Alexandre Torgue
  0 siblings, 0 replies; 2+ messages in thread
From: Alexandre Torgue @ 2016-04-05  9:24 UTC (permalink / raw)
  To: kernel-janitors

Hello Dan,

On 04/04/2016 10:46 PM, Dan Carpenter wrote:
> Hello Alexandre TORGUE,
>
> The patch 753a71090f33: "stmmac: add descriptors function for GMAC
> 4.xx" from Apr 1, 2016, leads to the following static checker warning:
>
> 	drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c:261 dwmac4_rd_prepare_tx_desc()
> 	warn: odd binop '0x4000 & 0x3fff'
>
> drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
>     251  static void dwmac4_rd_prepare_tx_desc(struct dma_desc *p, int is_fs, int len,
>     252                                        bool csum_flag, int mode, bool tx_own,
>     253                                        bool ls)
>     254  {
>     255          unsigned int tdes3 = p->des3;
>     256
>     257          if (unlikely(len > BUF_SIZE_16KiB)) {
>     258                  p->des2 |= (((len - BUF_SIZE_16KiB) <<
>     259                               TDES2_BUFFER2_SIZE_MASK_SHIFT)
>     260                              & TDES2_BUFFER2_SIZE_MASK)
>     261                              | (BUF_SIZE_16KiB & TDES2_BUFFER1_SIZE_MASK);
>                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> Should this be "len & TDES2_BUFFER1_SIZE_MASK" or are you rounding down
> the length deliberately?

It is a mistake. Could be "len & TDES2_BUFFER1_SIZE_MASK" or 
"(BUF_SIZE_16KiB - 1) & TDES2_BUFFER1_SIZE_MASK".
I will send a fix.

Thanks.

regards,

Alex

>
>     262          } else {
>     263                  p->des2 |= (len & TDES2_BUFFER1_SIZE_MASK);
>     264          }
>     265
>     266          if (is_fs)
>     267                  tdes3 |= TDES3_FIRST_DESCRIPTOR;
>     268          else
>     269                  tdes3 &= ~TDES3_FIRST_DESCRIPTOR;
>     270
>
> regards,
> dan carpenter
>



^ permalink raw reply	[flat|nested] 2+ messages in thread

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2016-04-04 20:46 stmmac: add descriptors function for GMAC 4.xx Dan Carpenter
2016-04-05  9:24 ` Alexandre Torgue

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