| Message ID | 503A852B.8010902@yahoo.es (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Hein, Thanks for your investigation about the MCI issue with AVR chips. Le 08/26/2012 10:20 PM, Hein Tibosch a écrit : > After the latest changes to atmel-mci, it could not be used with > DMA on the AVR32 platform. This patch will allow to use DMA again > and it will avoid access to MCI register ATMCI_DMA. > I think you should add more details about the issue: Even if the IP version is lower than v3xx and doesn't have the DMA configuration register, DMA transfers can be used with a different controller than the Atmel AHB DMA one. For instance, some AVR chips use the Synopsys DesignWare AHB DMA controller. > Signed-off-by: Hein Tibosch <hein_tibosch@yahoo.es> > Some comments below... > --- > drivers/mmc/host/atmel-mci.c | 21 +++++++++------------ > 1 files changed, 9 insertions(+), 12 deletions(-) > > diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c > index f2c115e..66e9fdc 100644 > --- a/drivers/mmc/host/atmel-mci.c > +++ b/drivers/mmc/host/atmel-mci.c > @@ -71,7 +71,7 @@ enum atmci_pdc_buf { > }; > > struct atmel_mci_caps { > - bool has_dma; > + bool has_dma_conf_reg; > bool has_pdc; > bool has_cfg_reg; > bool has_cstor_reg; > @@ -411,7 +411,7 @@ static int atmci_regs_show(struct seq_file *s, void *v) > atmci_show_status_reg(s, "SR", buf[ATMCI_SR / 4]); > atmci_show_status_reg(s, "IMR", buf[ATMCI_IMR / 4]); > > - if (host->caps.has_dma) { > + if (host->caps.has_dma_conf_reg) { > u32 val; > > val = buf[ATMCI_DMA / 4]; > @@ -767,7 +767,7 @@ static void atmci_dma_complete(void *arg) > > dev_vdbg(&host->pdev->dev, "DMA complete\n"); > > - if (host->caps.has_dma) > + if (host->caps.has_dma_conf_reg) > /* Disable DMA hardware handshaking on MCI */ > atmci_writel(host, ATMCI_DMA, atmci_readl(host, ATMCI_DMA) & ~ATMCI_DMAEN); > > @@ -954,7 +954,9 @@ atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data) > maxburst = atmci_convert_chksize(host->dma_conf.dst_maxburst); > } > > - atmci_writel(host, ATMCI_DMA, ATMCI_DMA_CHKSIZE(maxburst) | ATMCI_DMAEN); > + if (host->caps.has_dma_conf_reg) > + atmci_writel(host, ATMCI_DMA, ATMCI_DMA_CHKSIZE(maxburst) | > + ATMCI_DMAEN); > > sglen = dma_map_sg(chan->device->dev, data->sg, > data->sg_len, direction); > @@ -2202,7 +2204,7 @@ static void __init atmci_get_cap(struct atmel_mci *host) > dev_info(&host->pdev->dev, > "version: 0x%x\n", version); > > - host->caps.has_dma = 0; > + host->caps.has_dma_conf_reg = 0; > host->caps.has_pdc = 1; > host->caps.has_cfg_reg = 0; > host->caps.has_cstor_reg = 0; > @@ -2219,12 +2221,7 @@ static void __init atmci_get_cap(struct atmel_mci *host) > host->caps.has_odd_clk_div = 1; > case 0x400: > case 0x300: > -#ifdef CONFIG_AT_HDMAC > - host->caps.has_dma = 1; > -#else > - dev_info(&host->pdev->dev, > - "has dma capability but dma engine is not selected, then use pio\n"); > -#endif > + host->caps.has_dma_conf_reg = 1; > host->caps.has_pdc = 0; > host->caps.has_cfg_reg = 1; > host->caps.has_cstor_reg = 1; > @@ -2298,7 +2295,7 @@ static int __init atmci_probe(struct platform_device *pdev) > > /* Get MCI capabilities and set operations according to it */ > atmci_get_cap(host); > - if (host->caps.has_dma && atmci_configure_dma(host)) { > + if (atmci_configure_dma(host)) { > host->prepare_data = &atmci_prepare_data_dma; > host->submit_data = &atmci_submit_data_dma; > host->stop_transfer = &atmci_stop_transfer_dma; > I have tested this patch on at91sam9m10g45, at91sam9g10 and at91sam9261. For chips without MCI support for Atmel AHB DMA, removing the host->caps.has_dma test involves to use pdata->dma_slave with more caution to avoid some NULL pointer dereferences @@ -2168,16 +2168,21 @@ static bool atmci_configure_dma(struct atmel_mci *host) return false; pdata = host->pdev->dev.platform_data; + if (!pdata) + return false; - if (pdata && find_slave_dev(pdata->dma_slave)) { + if (pdata->dma_slave && find_slave_dev(pdata->dma_slave)) { dma_cap_mask_t mask; Regards Ludovic
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c index f2c115e..66e9fdc 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -71,7 +71,7 @@ enum atmci_pdc_buf { }; struct atmel_mci_caps { - bool has_dma; + bool has_dma_conf_reg; bool has_pdc; bool has_cfg_reg; bool has_cstor_reg; @@ -411,7 +411,7 @@ static int atmci_regs_show(struct seq_file *s, void *v) atmci_show_status_reg(s, "SR", buf[ATMCI_SR / 4]); atmci_show_status_reg(s, "IMR", buf[ATMCI_IMR / 4]); - if (host->caps.has_dma) { + if (host->caps.has_dma_conf_reg) { u32 val; val = buf[ATMCI_DMA / 4]; @@ -767,7 +767,7 @@ static void atmci_dma_complete(void *arg) dev_vdbg(&host->pdev->dev, "DMA complete\n"); - if (host->caps.has_dma) + if (host->caps.has_dma_conf_reg) /* Disable DMA hardware handshaking on MCI */ atmci_writel(host, ATMCI_DMA, atmci_readl(host, ATMCI_DMA) & ~ATMCI_DMAEN); @@ -954,7 +954,9 @@ atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data) maxburst = atmci_convert_chksize(host->dma_conf.dst_maxburst); } - atmci_writel(host, ATMCI_DMA, ATMCI_DMA_CHKSIZE(maxburst) | ATMCI_DMAEN); + if (host->caps.has_dma_conf_reg) + atmci_writel(host, ATMCI_DMA, ATMCI_DMA_CHKSIZE(maxburst) | + ATMCI_DMAEN); sglen = dma_map_sg(chan->device->dev, data->sg, data->sg_len, direction); @@ -2202,7 +2204,7 @@ static void __init atmci_get_cap(struct atmel_mci *host) dev_info(&host->pdev->dev, "version: 0x%x\n", version); - host->caps.has_dma = 0; + host->caps.has_dma_conf_reg = 0; host->caps.has_pdc = 1; host->caps.has_cfg_reg = 0; host->caps.has_cstor_reg = 0; @@ -2219,12 +2221,7 @@ static void __init atmci_get_cap(struct atmel_mci *host) host->caps.has_odd_clk_div = 1; case 0x400: case 0x300: -#ifdef CONFIG_AT_HDMAC - host->caps.has_dma = 1; -#else - dev_info(&host->pdev->dev, - "has dma capability but dma engine is not selected, then use pio\n"); -#endif + host->caps.has_dma_conf_reg = 1; host->caps.has_pdc = 0; host->caps.has_cfg_reg = 1; host->caps.has_cstor_reg = 1; @@ -2298,7 +2295,7 @@ static int __init atmci_probe(struct platform_device *pdev) /* Get MCI capabilities and set operations according to it */ atmci_get_cap(host); - if (host->caps.has_dma && atmci_configure_dma(host)) { + if (atmci_configure_dma(host)) { host->prepare_data = &atmci_prepare_data_dma; host->submit_data = &atmci_submit_data_dma; host->stop_transfer = &atmci_stop_transfer_dma;
After the latest changes to atmel-mci, it could not be used with DMA on the AVR32 platform. This patch will allow to use DMA again and it will avoid access to MCI register ATMCI_DMA. Signed-off-by: Hein Tibosch <hein_tibosch@yahoo.es> --- drivers/mmc/host/atmel-mci.c | 21 +++++++++------------ 1 files changed, 9 insertions(+), 12 deletions(-)