Re: [PATCH 2/2] mmc: dw_mmc: add dw_mci_prepare_desc() for both of 32bit and 64bit DMA

[kernel test robot <lkp@intel.com>]

Hi Shawn,

kernel test robot noticed the following build warnings:

[auto build test WARNING on linus/master]
[also build test WARNING on ulf-hansson-mmc-mirror/next v6.18-rc6 next-20251120]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Shawn-Lin/mmc-dw_mmc-add-dw_mci_prepare_desc-for-both-of-32bit-and-64bit-DMA/20251119-163950
base:   linus/master
patch link:    https://lore.kernel.org/r/1763540498-84315-2-git-send-email-shawn.lin%40rock-chips.com
patch subject: [PATCH 2/2] mmc: dw_mmc: add dw_mci_prepare_desc() for both of 32bit and 64bit DMA
config: arm64-randconfig-r121-20251120 (https://download.01.org/0day-ci/archive/20251120/202511202301.b4PYJbNg-lkp@intel.com/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project 0bba1e76581bad04e7d7f09f5115ae5e2989e0d9)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251120/202511202301.b4PYJbNg-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202511202301.b4PYJbNg-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> drivers/mmc/host/dw_mmc.c:609:29: sparse: sparse: incompatible types in conditional expression (different base types):
   drivers/mmc/host/dw_mmc.c:609:29: sparse:    unsigned int *
   drivers/mmc/host/dw_mmc.c:609:29: sparse:    restricted __le32 *

vim +609 drivers/mmc/host/dw_mmc.c

   577	
   578	static inline int dw_mci_prepare_desc(struct dw_mci *host, struct mmc_data *data,
   579					      unsigned int sg_len, bool is_64bit)
   580	{
   581		unsigned int desc_len;
   582		struct idmac_desc *desc_first, *desc_last, *desc;
   583		struct idmac_desc_64addr *desc64_first, *desc64_last, *desc64;
   584		u32 val, des0;
   585		int i;
   586	
   587		if (is_64bit)
   588			desc64_first = desc64_last = desc64 = host->sg_cpu;
   589		else
   590			desc_first = desc_last = desc = host->sg_cpu;
   591	
   592		for (i = 0; i < sg_len; i++) {
   593			unsigned int length = sg_dma_len(&data->sg[i]);
   594	
   595			u64 mem_addr = sg_dma_address(&data->sg[i]);
   596	
   597			for ( ; length ; desc++) {
   598				desc_len = (length <= DW_MCI_DESC_DATA_LENGTH) ?
   599					   length : DW_MCI_DESC_DATA_LENGTH;
   600	
   601				length -= desc_len;
   602	
   603				/*
   604				 * Wait for the former clear OWN bit operation
   605				 * of IDMAC to make sure that this descriptor
   606				 * isn't still owned by IDMAC as IDMAC's write
   607				 * ops and CPU's read ops are asynchronous.
   608				 */
 > 609				if (readl_poll_timeout_atomic(is_64bit ? &desc64->des0 : &desc->des0,
   610							val, IDMAC_OWN_CLR64(val), 10, 100 * USEC_PER_MSEC))
   611					goto err_own_bit;
   612	
   613				des0 = IDMAC_DES0_OWN | IDMAC_DES0_DIC | IDMAC_DES0_CH;
   614				if (is_64bit)
   615					desc64->des0 = des0;
   616				else
   617					desc->des0 = cpu_to_le32(des0);
   618	
   619				/*
   620				 * 1. Set OWN bit and disable interrupts for this descriptor
   621				 * 2. Set Buffer length
   622				 * Set physical address to DMA to/from
   623				 */
   624				if (is_64bit) {
   625					desc64->des0 = IDMAC_DES0_OWN | IDMAC_DES0_DIC | IDMAC_DES0_CH;
   626					IDMAC_64ADDR_SET_BUFFER1_SIZE(desc64, desc_len);
   627					desc64->des4 = mem_addr & 0xffffffff;
   628					desc64->des5 = mem_addr >> 32;
   629				} else {
   630					IDMAC_SET_BUFFER1_SIZE(desc, desc_len);
   631					desc->des2 = cpu_to_le32(mem_addr);
   632				}
   633	
   634				/* Update physical address for the next desc */
   635				mem_addr += desc_len;
   636	
   637				/* Save pointer to the last descriptor */
   638				if (is_64bit)
   639					desc64_last = desc64;
   640				else
   641					desc_last = desc;
   642			}
   643		}
   644	
   645		/* Set the first descriptor and the last descriptor */
   646		if (is_64bit) {
   647			desc64_first->des0 |= IDMAC_DES0_FD;
   648			desc64_last->des0 &= ~(IDMAC_DES0_CH | IDMAC_DES0_DIC);
   649			desc64_last->des0 |= IDMAC_DES0_LD;
   650		} else {
   651			desc_first->des0 |= cpu_to_le32(IDMAC_DES0_FD);
   652			desc_last->des0 &= cpu_to_le32(~(IDMAC_DES0_CH | IDMAC_DES0_DIC));
   653			desc_last->des0 |= cpu_to_le32(IDMAC_DES0_LD);
   654		}
   655	
   656		return 0;
   657	err_own_bit:
   658		/* restore the descriptor chain as it's polluted */
   659		dev_dbg(host->dev, "descriptor is still owned by IDMAC.\n");
   660		memset(host->sg_cpu, 0, DESC_RING_BUF_SZ);
   661		dw_mci_idmac_init(host);
   662		return -EINVAL;
   663	}
   664	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki