Hi, On Sun, Oct 14, 2018 at 7:04 PM Aaro Koskinen <aaro.koskinen@xxxxxx> wrote: > > Hi, > > There is something wrong with jz4740-mmc in current mainline kernel > (tested v4.18 and 4.19-rc, the MMC support for CI20 does not exist > prior those), as the DMA support does not work properly if I disable > kernel pre-emption. The console gets flooded with: > > [ 16.461094] jz4740-mmc 13450000.mmc: [jz4740_mmc_prepare_dma_data] invalid cookie: data->host_cookie 567 host->next_data.cookie 568 > [ 16.473120] jz4740-mmc 13450000.mmc: [jz4740_mmc_prepare_dma_data] invalid cookie: data->host_cookie 568 host->next_data.cookie 569 > [ 16.485144] jz4740-mmc 13450000.mmc: [jz4740_mmc_prepare_dma_data] invalid cookie: data->host_cookie 569 host->next_data.cookie 570 > [ 16.497170] jz4740-mmc 13450000.mmc: [jz4740_mmc_prepare_dma_data] invalid cookie: data->host_cookie 570 host->next_data.cookie 571 > [ 16.509194] jz4740-mmc 13450000.mmc: [jz4740_mmc_prepare_dma_data] invalid cookie: data->host_cookie 571 host->next_data.cookie 572 > [ 16.532421] jz4740-mmc 13450000.mmc: [jz4740_mmc_prepare_dma_data] invalid cookie: data->host_cookie 572 host->next_data.cookie 573 > [ 16.544594] jz4740-mmc 13450000.mmc: [jz4740_mmc_prepare_dma_data] invalid cookie: data->host_cookie 573 host->next_data.cookie 574 > [ 16.556621] jz4740-mmc 13450000.mmc: [jz4740_mmc_prepare_dma_data] invalid cookie: data->host_cookie 574 host->next_data.cookie 575 > [ 16.568638] jz4740-mmc 13450000.mmc: [jz4740_mmc_prepare_dma_data] invalid cookie: data->host_cookie 575 host->next_data.cookie 576 > [ 16.601092] jz4740-mmc 13450000.mmc: [jz4740_mmc_prepare_dma_data] invalid cookie: data->host_cookie 582 host->next_data.cookie 583 > > etc. ad inf. > > This should be easily reproducible on CI20 board with ci20_defconfig > and setting CONFIG_PREEMPT_NONE=y. Since CONFIG_PREEMPT has been 'y' since at least commit 0752f92934292 could you confirm that the original mmc driver (kernel from imgtech people) did work ok with PREEMPT_NONE (sorry I did not do my homework) ? Thanks > A.