sparse reports: drivers/gpu/drm/omapdrm/omap_dmm_tiler.c:122:16: warning: incorrect type in argument 1 (different address spaces) drivers/gpu/drm/omapdrm/omap_dmm_tiler.c:122:16: expected void const volatile [noderef] __iomem *addr drivers/gpu/drm/omapdrm/omap_dmm_tiler.c:122:16: got unsigned int [usertype] *wa_dma_data drivers/gpu/drm/omapdrm/omap_dmm_tiler.c:130:9: warning: incorrect type in argument 2 (different address spaces) drivers/gpu/drm/omapdrm/omap_dmm_tiler.c:130:9: expected void volatile [noderef] __iomem *addr drivers/gpu/drm/omapdrm/omap_dmm_tiler.c:130:9: got unsigned int [usertype] *wa_dma_data drivers/gpu/drm/omapdrm/omap_dmm_tiler.c:414:9: warning: incorrect type in argument 1 (different address spaces) drivers/gpu/drm/omapdrm/omap_dmm_tiler.c:414:9: expected void const volatile [noderef] __iomem *addr drivers/gpu/drm/omapdrm/omap_dmm_tiler.c:414:9: got unsigned int *
These come from pieces of code which do essentially: p = dma_alloc_coherent() dma_transfer_to_p() readl(p) writel(x, p) dma_transfer_from_p() I think we would do just fine without readl() and writel(), accessing the memory without any extras, but ensuring that the necessary barriers are in place. But this code is for a legacy platform, has been working for ages, and it's doing work-arounds for hardware issues, and those hardware issues are very difficult to trigger... So I would just rather leave the code be as it is now. However, the warnings are not nice. Hide the warnings by a (__iomem void *) typecast. Signed-off-by: Tomi Valkeinen <tomi.valkei...@ideasonboard.com> Reported-by: kernel test robot <l...@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202407311737.vsj0sr1w-...@intel.com/ Cc: Ville Syrjälä <ville.syrj...@linux.intel.com> --- drivers/gpu/drm/omapdrm/omap_dmm_tiler.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c b/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c index 1aca3060333e..fcd600024136 100644 --- a/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c +++ b/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c @@ -119,7 +119,7 @@ static u32 dmm_read_wa(struct dmm *dmm, u32 reg) * earlier than the DMA finished writing the value to memory. */ rmb(); - return readl(dmm->wa_dma_data); + return readl((__iomem void *)dmm->wa_dma_data); } static void dmm_write_wa(struct dmm *dmm, u32 val, u32 reg) @@ -127,7 +127,7 @@ static void dmm_write_wa(struct dmm *dmm, u32 val, u32 reg) dma_addr_t src, dst; int r; - writel(val, dmm->wa_dma_data); + writel(val, (__iomem void *)dmm->wa_dma_data); /* * As per i878 workaround, the DMA is used to access the DMM registers. * Make sure that the writel is not moved by the compiler or the CPU, so @@ -411,7 +411,7 @@ static int dmm_txn_commit(struct dmm_txn *txn, bool wait) */ /* read back to ensure the data is in RAM */ - readl(&txn->last_pat->next_pa); + readl((__iomem void *)&txn->last_pat->next_pa); /* write to PAT_DESCR to clear out any pending transaction */ dmm_write(dmm, 0x0, reg[PAT_DESCR][engine->id]); -- 2.43.0
