Re: [PATCH 1/1] dmaengine: fsl-dma: fix DMA error when enabling sg if 'DONE' bit is set

From: kernel test robot
Date: Thu Sep 21 2023 - 13:02:50 EST


Hi Frank,

kernel test robot noticed the following build warnings:

[auto build test WARNING on linus/master]
[also build test WARNING on v6.6-rc2 next-20230921]
[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/Frank-Li/dmaengine-fsl-dma-fix-DMA-error-when-enabling-sg-if-DONE-bit-is-set/20230921-043838
base: linus/master
patch link: https://lore.kernel.org/r/20230920203741.3184727-1-Frank.Li%40nxp.com
patch subject: [PATCH 1/1] dmaengine: fsl-dma: fix DMA error when enabling sg if 'DONE' bit is set
config: i386-randconfig-062-20230921 (https://download.01.org/0day-ci/archive/20230921/202309211717.aYksVles-lkp@xxxxxxxxx/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230921/202309211717.aYksVles-lkp@xxxxxxxxx/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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202309211717.aYksVles-lkp@xxxxxxxxx/

sparse warnings: (new ones prefixed by >>)
drivers/dma/fsl-edma-common.c:76:15: sparse: sparse: cast removes address space '__iomem' of expression
drivers/dma/fsl-edma-common.c:93:9: sparse: sparse: cast removes address space '__iomem' of expression
drivers/dma/fsl-edma-common.c:96:17: sparse: sparse: cast removes address space '__iomem' of expression
drivers/dma/fsl-edma-common.c:98:15: sparse: sparse: cast removes address space '__iomem' of expression
drivers/dma/fsl-edma-common.c:100:9: sparse: sparse: cast removes address space '__iomem' of expression
drivers/dma/fsl-edma-common.c:125:19: sparse: sparse: cast removes address space '__iomem' of expression
drivers/dma/fsl-edma-common.c:131:17: sparse: sparse: cast removes address space '__iomem' of expression
drivers/dma/fsl-edma-common.c:134:9: sparse: sparse: cast removes address space '__iomem' of expression
>> drivers/dma/fsl-edma-common.c:463:21: sparse: sparse: restricted __le16 degrades to integer
drivers/dma/fsl-edma-common.c:465:21: sparse: sparse: restricted __le16 degrades to integer
drivers/dma/fsl-edma-common.c:466:17: sparse: sparse: cast removes address space '__iomem' of expression
drivers/dma/fsl-edma-common.c:466:17: sparse: sparse: cast removes address space '__iomem' of expression

vim +463 drivers/dma/fsl-edma-common.c

422
423 static void fsl_edma_set_tcd_regs(struct fsl_edma_chan *fsl_chan,
424 struct fsl_edma_hw_tcd *tcd)
425 {
426 u16 csr = 0;
427
428 /*
429 * TCD parameters are stored in struct fsl_edma_hw_tcd in little
430 * endian format. However, we need to load the TCD registers in
431 * big- or little-endian obeying the eDMA engine model endian,
432 * and this is performed from specific edma_write functions
433 */
434 edma_write_tcdreg(fsl_chan, 0, csr);
435
436 edma_write_tcdreg(fsl_chan, tcd->saddr, saddr);
437 edma_write_tcdreg(fsl_chan, tcd->daddr, daddr);
438
439 edma_write_tcdreg(fsl_chan, tcd->attr, attr);
440 edma_write_tcdreg(fsl_chan, tcd->soff, soff);
441
442 edma_write_tcdreg(fsl_chan, tcd->nbytes, nbytes);
443 edma_write_tcdreg(fsl_chan, tcd->slast, slast);
444
445 edma_write_tcdreg(fsl_chan, tcd->citer, citer);
446 edma_write_tcdreg(fsl_chan, tcd->biter, biter);
447 edma_write_tcdreg(fsl_chan, tcd->doff, doff);
448
449 edma_write_tcdreg(fsl_chan, tcd->dlast_sga, dlast_sga);
450
451 if (fsl_chan->is_sw) {
452 csr = le16_to_cpu(tcd->csr);
453 csr |= EDMA_TCD_CSR_START;
454 tcd->csr = cpu_to_le16(csr);
455 }
456
457 /*
458 * Must clear CHn_CSR[DONE] bit before enable TCDn_CSR[ESG] at EDMAv3
459 * eDMAv4 have not such requirement.
460 * Change MLINK need clear CHn_CSR[DONE] for both eDMAv3 and eDMAv4.
461 */
462 if (((fsl_edma_drvflags(fsl_chan) & FSL_EDMA_DRV_CLEAR_DONE_E_SG) &&
> 463 (tcd->csr & EDMA_TCD_CSR_E_SG)) ||
464 ((fsl_edma_drvflags(fsl_chan) & FSL_EDMA_DRV_CLEAR_DONE_E_LINK) &&
465 (tcd->csr & EDMA_TCD_CSR_E_LINK)))
466 edma_writel_chreg(fsl_chan, edma_readl_chreg(fsl_chan, ch_csr), ch_csr);
467
468
469 edma_write_tcdreg(fsl_chan, tcd->csr, csr);
470 }
471

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