Messages in this thread Patch in this message |  | | Subject | Re: [PATCH V4 02/25] mmc: mmci: create generic mmci_dma_setup | From | Ludovic BARRE <> | Date | Wed, 3 Oct 2018 13:44:01 +0200 |
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hi Ulf
On 10/03/2018 11:22 AM, Ulf Hansson wrote: > + Srinivas
for next series, I will add Srinivas
> > [...] > >> #ifdef CONFIG_DMA_ENGINE >> -static void mmci_dma_setup(struct mmci_host *host) >> +static inline void mmci_dma_release(struct mmci_host *host); >> + >> +int mmci_dmae_setup(struct mmci_host *host) >> { >> const char *rxname, *txname; >> >> @@ -464,8 +485,12 @@ static void mmci_dma_setup(struct mmci_host *host) >> host->mmc->max_seg_size = max_seg_size; >> } >> >> - if (host->ops && host->ops->dma_setup) >> - host->ops->dma_setup(host); >> + if (!host->dma_tx_channel || !host->dma_rx_channel) { >> + mmci_dma_release(host); > > This doesn't look right to me. The existing code allows a tx channel > to be used, even if an rx channel could not be setup. It seems > reasonable to still allow that.
ok, I could replace by if (!host->dma_tx_channel && !host->dma_rx_channel)
> >> + return -EINVAL; >> + } >> + >> + return 0; >> } >> >> /* >> @@ -496,7 +521,7 @@ static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data) >> >> static void mmci_dma_data_error(struct mmci_host *host) >> { >> - if (!dma_inprogress(host)) >> + if (!host->use_dma || !dma_inprogress(host)) > > Adding the check for use_dma here seems like an unnecessary check, > unless there is a reason for it due to following changes on top. In > such case, please make it a part of the patch(es) where it's actually > needed.
In Fact, these checks are add to ensure the pio fallback, if only this patch it's taken. In the next commit of serie, these checks are moved to common functions mmci_dma_XX function.
> >> return; >> >> dev_err(mmc_dev(host->mmc), "error during DMA transfer!\n"); >> @@ -514,7 +539,7 @@ static void mmci_dma_finalize(struct mmci_host *host, struct mmc_data *data) >> u32 status; >> int i; >> >> - if (!dma_inprogress(host)) >> + if (!host->use_dma || !dma_inprogress(host)) > > Ditto. > >> return; >> >> /* Wait up to 1ms for the DMA to complete */ >> @@ -546,6 +571,7 @@ static void mmci_dma_finalize(struct mmci_host *host, struct mmc_data *data) >> if (status & MCI_RXDATAAVLBLMASK) { >> dev_err(mmc_dev(host->mmc), "buggy DMA detected. Taking evasive action.\n"); >> mmci_dma_release(host); >> + host->use_dma = false; >> } >> >> host->dma_in_progress = false; >> @@ -640,6 +666,9 @@ static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl) >> int ret; >> struct mmc_data *data = host->data; >> >> + if (!host->use_dma) >> + return -EINVAL; >> + >> ret = mmci_dma_prep_data(host, host->data); >> if (ret) >> return ret; >> @@ -674,6 +703,9 @@ static void mmci_get_next_data(struct mmci_host *host, struct mmc_data *data) >> { >> struct mmci_host_next *next = &host->next_data; >> >> + if (!host->use_dma) >> + return; >> + >> WARN_ON(data->host_cookie && data->host_cookie != next->cookie); >> WARN_ON(!data->host_cookie && (next->dma_desc || next->dma_chan)); >> >> @@ -689,7 +721,7 @@ static void mmci_pre_request(struct mmc_host *mmc, struct mmc_request *mrq) >> struct mmc_data *data = mrq->data; >> struct mmci_host_next *nd = &host->next_data; >> >> - if (!data) >> + if (!host->use_dma || !data) >> return; >> >> BUG_ON(data->host_cookie); >> @@ -707,7 +739,7 @@ static void mmci_post_request(struct mmc_host *mmc, struct mmc_request *mrq, >> struct mmci_host *host = mmc_priv(mmc); >> struct mmc_data *data = mrq->data; >> >> - if (!data || !data->host_cookie) >> + if (!host->use_dma || !data || !data->host_cookie) > > Ditto. > >> return; >> >> mmci_dma_unmap(host, data); >> @@ -735,14 +767,14 @@ static void mmci_post_request(struct mmc_host *mmc, struct mmc_request *mrq, >> } >> } >> >> +static struct mmci_host_ops mmci_variant_ops = { >> + .dma_setup = mmci_dmae_setup, >> +}; >> #else >> /* Blank functions if the DMA engine is not available */ >> 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 void mmci_dma_release(struct mmci_host *host) >> { >> @@ -765,8 +797,14 @@ static inline int mmci_dma_start_data(struct mmci_host *host, unsigned int datac >> #define mmci_pre_request NULL >> #define mmci_post_request NULL >> >> +static struct mmci_host_ops mmci_variant_ops = {}; > > This seems a bit unnecessary. See more about why, below. > >> #endif >> >> +void mmci_variant_init(struct mmci_host *host) > > Looks like you should make mmci_variant_init() internal to mmci.c, > thus covert it to static. > > Moreover, I suggest you define a "static inline void > mmci_variant_init()", when CONFIG_DMA_ENGINE is unset. In that way you > don't need to assign host->ops at all for this case.
OK, no problem
> >> +{ >> + host->ops = &mmci_variant_ops; >> +} >> + >> static void mmci_start_data(struct mmci_host *host, struct mmc_data *data) >> { >> struct variant_data *variant = host->variant; >> diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h >> index 01e6c6b..f7fe80f 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 { >> @@ -323,6 +323,7 @@ struct mmci_host { >> unsigned int size; >> int (*get_rx_fifocnt)(struct mmci_host *h, u32 status, int remain); >> >> + u8 use_dma:1; >> #ifdef CONFIG_DMA_ENGINE >> /* DMA stuff */ >> struct dma_chan *dma_current; >> @@ -336,3 +337,7 @@ struct mmci_host { >> #endif >> }; >> >> +void mmci_variant_init(struct mmci_host *host); >> + >> +int mmci_dmae_setup(struct mmci_host *host); >> + >> diff --git a/drivers/mmc/host/mmci_qcom_dml.c b/drivers/mmc/host/mmci_qcom_dml.c >> index be3fab5..c8d7592 100644 >> --- a/drivers/mmc/host/mmci_qcom_dml.c >> +++ b/drivers/mmc/host/mmci_qcom_dml.c >> @@ -119,19 +119,22 @@ 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; >> int consumer_id, producer_id; >> struct device_node *np = host->mmc->parent->of_node; >> >> + if (mmci_dmae_setup(host)) >> + return -EINVAL; >> + >> consumer_id = of_get_dml_pipe_index(np, "tx"); >> producer_id = of_get_dml_pipe_index(np, "rx"); >> >> if (producer_id < 0 || consumer_id < 0) { >> host->variant->qcom_dml = false; >> - return; >> + return -EINVAL; > > Seems like you need to call a corresponding dma release function here, > before returning the error code. > > Probably an "mmci_dmae_release()" needs to be implemented as a part of > this change - and then also called from here. This is according to > Srinivas recommendations, which means falling back to pio. As a matter > of fact this also needs to be clearly stated in the changelog, as you > are really also improving the behavior for the Qcom variant.
it's in relation with the comment on + if (!host->dma_tx_channel || !host->dma_rx_channel) {
So yes. At first sight Qcom need to have a tx and rx channel, I will add mmci_dmae_release before returning error code.
> > Unfortunate, I am not able to test this as I don't have the HW (which > I thought I had). Perhaps Srinivas can help, once we have something > ready for him to test. > >> } >> >> base = host->base + DML_OFFSET; >> @@ -175,6 +178,8 @@ 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 >
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