| Message ID | 20200526155103.12514-2-ludovic.barre@st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mmc: mmci_sdmmc: fix dma api warnings | expand |
On Tue, 26 May 2020 at 17:51, Ludovic Barre <ludovic.barre@st.com> wrote: > > Turning on CONFIG_DMA_API_DEBUG_SG results in the following warning: > WARNING: CPU: 1 PID: 20 at kernel/dma/debug.c:500 add_dma_entry+0x16c/0x17c > DMA-API: exceeded 7 overlapping mappings of cacheline 0x031d2645 > Modules linked in: > CPU: 1 PID: 20 Comm: kworker/1:1 Not tainted 5.5.0-rc2-00021-gdeda30999c2b-dirty #49 > Hardware name: STM32 (Device Tree Support) > Workqueue: events_freezable mmc_rescan > [<c03138c0>] (unwind_backtrace) from [<c030d760>] (show_stack+0x10/0x14) > [<c030d760>] (show_stack) from [<c0f2eb28>] (dump_stack+0xc0/0xd4) > [<c0f2eb28>] (dump_stack) from [<c034a14c>] (__warn+0xd0/0xf8) > [<c034a14c>] (__warn) from [<c034a530>] (warn_slowpath_fmt+0x94/0xb8) > [<c034a530>] (warn_slowpath_fmt) from [<c03bca0c>] (add_dma_entry+0x16c/0x17c) > [<c03bca0c>] (add_dma_entry) from [<c03bdf54>] (debug_dma_map_sg+0xe4/0x3d4) > [<c03bdf54>] (debug_dma_map_sg) from [<c0d09244>] (sdmmc_idma_prep_data+0x94/0xf8) > [<c0d09244>] (sdmmc_idma_prep_data) from [<c0d05a2c>] (mmci_prep_data+0x2c/0xb0) > [<c0d05a2c>] (mmci_prep_data) from [<c0d073ec>] (mmci_start_data+0x134/0x2f0) > [<c0d073ec>] (mmci_start_data) from [<c0d078d0>] (mmci_request+0xe8/0x154) > [<c0d078d0>] (mmci_request) from [<c0cecb44>] (mmc_start_request+0x94/0xbc) > > DMA api debug brings to light leaking dma-mappings, dma_map_sg and > dma_unmap_sg are not correctly balanced. > > If a request is prepared, the dma_map/unmap are done in asynchronous > call pre_req (prep_data) and post_req (unprep_data). In this case > the dma-mapping is right balanced. > > But if the request was not prepared, the data->host_cookie is > define to zero and the dma_map/unmap must be done in the request. > The dma_map is called by mmci_dma_start (prep_data), but there is > no dma_unmap in this case. > > This patch adds dma_unmap_sg when the dma is finalized and > the data cookie is zero (request not prepared). > > Signed-off-by: Ludovic Barre <ludovic.barre@st.com> Applied for next by adding a fixes tag and a stable tag, thanks! Fixes: 46b723dd867d ("mmc: mmci: add stm32 sdmmc variant") Kind regards Uffe > --- > drivers/mmc/host/mmci_stm32_sdmmc.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/mmc/host/mmci_stm32_sdmmc.c b/drivers/mmc/host/mmci_stm32_sdmmc.c > index 14f99d8aa3f0..2965b1c062e1 100644 > --- a/drivers/mmc/host/mmci_stm32_sdmmc.c > +++ b/drivers/mmc/host/mmci_stm32_sdmmc.c > @@ -188,6 +188,9 @@ static int sdmmc_idma_start(struct mmci_host *host, unsigned int *datactrl) > static void sdmmc_idma_finalize(struct mmci_host *host, struct mmc_data *data) > { > writel_relaxed(0, host->base + MMCI_STM32_IDMACTRLR); > + > + if (!data->host_cookie) > + sdmmc_idma_unprep_data(host, data, 0); > } > > static void mmci_sdmmc_set_clkreg(struct mmci_host *host, unsigned int desired) > -- > 2.17.1 >
diff --git a/drivers/mmc/host/mmci_stm32_sdmmc.c b/drivers/mmc/host/mmci_stm32_sdmmc.c index 14f99d8aa3f0..2965b1c062e1 100644 --- a/drivers/mmc/host/mmci_stm32_sdmmc.c +++ b/drivers/mmc/host/mmci_stm32_sdmmc.c @@ -188,6 +188,9 @@ static int sdmmc_idma_start(struct mmci_host *host, unsigned int *datactrl) static void sdmmc_idma_finalize(struct mmci_host *host, struct mmc_data *data) { writel_relaxed(0, host->base + MMCI_STM32_IDMACTRLR); + + if (!data->host_cookie) + sdmmc_idma_unprep_data(host, data, 0); } static void mmci_sdmmc_set_clkreg(struct mmci_host *host, unsigned int desired)
Turning on CONFIG_DMA_API_DEBUG_SG results in the following warning: WARNING: CPU: 1 PID: 20 at kernel/dma/debug.c:500 add_dma_entry+0x16c/0x17c DMA-API: exceeded 7 overlapping mappings of cacheline 0x031d2645 Modules linked in: CPU: 1 PID: 20 Comm: kworker/1:1 Not tainted 5.5.0-rc2-00021-gdeda30999c2b-dirty #49 Hardware name: STM32 (Device Tree Support) Workqueue: events_freezable mmc_rescan [<c03138c0>] (unwind_backtrace) from [<c030d760>] (show_stack+0x10/0x14) [<c030d760>] (show_stack) from [<c0f2eb28>] (dump_stack+0xc0/0xd4) [<c0f2eb28>] (dump_stack) from [<c034a14c>] (__warn+0xd0/0xf8) [<c034a14c>] (__warn) from [<c034a530>] (warn_slowpath_fmt+0x94/0xb8) [<c034a530>] (warn_slowpath_fmt) from [<c03bca0c>] (add_dma_entry+0x16c/0x17c) [<c03bca0c>] (add_dma_entry) from [<c03bdf54>] (debug_dma_map_sg+0xe4/0x3d4) [<c03bdf54>] (debug_dma_map_sg) from [<c0d09244>] (sdmmc_idma_prep_data+0x94/0xf8) [<c0d09244>] (sdmmc_idma_prep_data) from [<c0d05a2c>] (mmci_prep_data+0x2c/0xb0) [<c0d05a2c>] (mmci_prep_data) from [<c0d073ec>] (mmci_start_data+0x134/0x2f0) [<c0d073ec>] (mmci_start_data) from [<c0d078d0>] (mmci_request+0xe8/0x154) [<c0d078d0>] (mmci_request) from [<c0cecb44>] (mmc_start_request+0x94/0xbc) DMA api debug brings to light leaking dma-mappings, dma_map_sg and dma_unmap_sg are not correctly balanced. If a request is prepared, the dma_map/unmap are done in asynchronous call pre_req (prep_data) and post_req (unprep_data). In this case the dma-mapping is right balanced. But if the request was not prepared, the data->host_cookie is define to zero and the dma_map/unmap must be done in the request. The dma_map is called by mmci_dma_start (prep_data), but there is no dma_unmap in this case. This patch adds dma_unmap_sg when the dma is finalized and the data cookie is zero (request not prepared). Signed-off-by: Ludovic Barre <ludovic.barre@st.com> --- drivers/mmc/host/mmci_stm32_sdmmc.c | 3 +++ 1 file changed, 3 insertions(+)