Re: [PATCH V2 03/27] mmc: mmci: convert dma_setup callback to return an int
From: Ulf Hansson <hidden>
Date: 2018-09-24 14:28:51
Also in:
linux-arm-kernel, linux-mmc, lkml
On 21 September 2018 at 11:45, Ludovic Barre [off-list ref] wrote:
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From: Ludovic Barre <redacted> This patch converts dma_setup callback to return an integer This patch is needed to prepare sdmmc variant with internal dma Signed-off-by: Ludovic Barre <redacted> --- drivers/mmc/host/mmci.c | 14 ++++++++++---- drivers/mmc/host/mmci.h | 2 +- drivers/mmc/host/mmci_qcom_dml.c | 6 ++++-- 3 files changed, 15 insertions(+), 7 deletions(-)diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c index cbd67bc..2f845f3 100644 --- a/drivers/mmc/host/mmci.c +++ b/drivers/mmc/host/mmci.c@@ -415,7 +415,7 @@ static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data) * no custom DMA interfaces are supported. */ #ifdef CONFIG_DMA_ENGINE -static void mmci_dma_setup(struct mmci_host *host) +static int mmci_dma_setup(struct mmci_host *host) { const char *rxname, *txname;@@ -466,7 +466,9 @@ static void mmci_dma_setup(struct mmci_host *host) } if (host->ops && host->ops->dma_setup) - host->ops->dma_setup(host); + return host->ops->dma_setup(host); +
Looks like you need to implement a error handling, instead of just returning the error code.
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+ return 0; } /*@@ -741,8 +743,10 @@ static void mmci_post_request(struct mmc_host *mmc, struct mmc_request *mrq, static void mmci_get_next_data(struct mmci_host *host, struct mmc_data *data) { } -static inline void mmci_dma_setup(struct mmci_host *host) + +static inline int mmci_dma_setup(struct mmci_host *host) { + return 0; } static inline void mmci_dma_release(struct mmci_host *host)@@ -1796,7 +1800,9 @@ static int mmci_probe(struct amba_device *dev, amba_rev(dev), (unsigned long long)dev->res.start, dev->irq[0], dev->irq[1]); - mmci_dma_setup(host); + ret = mmci_dma_setup(host); + if (ret) + goto clk_disable; pm_runtime_set_autosuspend_delay(&dev->dev, 50); pm_runtime_use_autosuspend(&dev->dev);diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h index 21aaf9a..06299ac 100644 --- a/drivers/mmc/host/mmci.h +++ b/drivers/mmc/host/mmci.h@@ -273,7 +273,7 @@ struct variant_data { /* mmci variant callbacks */ struct mmci_host_ops { - void (*dma_setup)(struct mmci_host *host); + int (*dma_setup)(struct mmci_host *host); }; struct mmci_host_next {diff --git a/drivers/mmc/host/mmci_qcom_dml.c b/drivers/mmc/host/mmci_qcom_dml.c index be3fab5..1bb59cf 100644 --- a/drivers/mmc/host/mmci_qcom_dml.c +++ b/drivers/mmc/host/mmci_qcom_dml.c@@ -119,7 +119,7 @@ static int of_get_dml_pipe_index(struct device_node *np, const char *name) } /* Initialize the dml hardware connected to SD Card controller */ -static void qcom_dma_setup(struct mmci_host *host) +static int qcom_dma_setup(struct mmci_host *host) { u32 config; void __iomem *base;@@ -131,7 +131,7 @@ static void qcom_dma_setup(struct mmci_host *host) if (producer_id < 0 || consumer_id < 0) { host->variant->qcom_dml = false;
It seems like the existing code is an attempt to fallback to use pio mode. However, I doubt it works as is.
- return; + return -EINVAL;
My point is, if you return an error code here, it means that the error code becomes propagated and ->probe() will fail. Ideally, we should be able fall back to pio mode when dma doesn't work. I have looped in Srinivas who implemented the qcom dml support, let's see if he can explains the intent with the code. I also volunteer to help out running some tests on the 410c platform, however allow me a day or two to do that.
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} base = host->base + DML_OFFSET;@@ -175,6 +175,8 @@ static void qcom_dma_setup(struct mmci_host *host) /* Make sure dml initialization is finished */ mb(); + + return 0; } static struct mmci_host_ops qcom_variant_ops = { --2.7.4
Kind regards Uffe