Hi Russell, Russell King <[email protected]> writes:
> Remove the private DMA API implementation from omap_hsmmc, making it > use entirely the DMA engine API. > > Signed-off-by: Russell King <[email protected]> While testing this, I noticed a minor problem in the case of probe failure (e.g. if dmaengine is not built into the kernel.) The current driver suffers from this same problem but should probably be fixed when converting to dmaengine... [...] > @@ -2048,36 +1919,28 @@ static int __devinit omap_hsmmc_probe(struct > platform_device *pdev) > dev_err(mmc_dev(host->mmc), "cannot get DMA TX channel\n"); > goto err_irq; > } > - host->dma_line_tx = res->start; > + tx_req = res->start; > > res = platform_get_resource_byname(pdev, IORESOURCE_DMA, "rx"); > if (!res) { > dev_err(mmc_dev(host->mmc), "cannot get DMA RX channel\n"); > goto err_irq; > } > - host->dma_line_rx = res->start; > + rx_req = res->start; > > - { > - dma_cap_mask_t mask; > - unsigned sig; > - extern bool omap_dma_filter_fn(struct dma_chan *chan, void > *param); > - > - dma_cap_zero(mask); > - dma_cap_set(DMA_SLAVE, mask); > -#if 1 > - sig = host->dma_line_rx; > - host->rx_chan = dma_request_channel(mask, omap_dma_filter_fn, > &sig); > - if (!host->rx_chan) { > - dev_warn(mmc_dev(host->mmc), "unable to obtain RX DMA > engine channel %u\n", sig); > - } > -#endif > -#if 1 > - sig = host->dma_line_tx; > - host->tx_chan = dma_request_channel(mask, omap_dma_filter_fn, > &sig); > - if (!host->tx_chan) { > - dev_warn(mmc_dev(host->mmc), "unable to obtain TX DMA > engine channel %u\n", sig); > - } > -#endif > + dma_cap_zero(mask); > + dma_cap_set(DMA_SLAVE, mask); > + > + host->rx_chan = dma_request_channel(mask, omap_dma_filter_fn, &rx_req); > + if (!host->rx_chan) { > + dev_err(mmc_dev(host->mmc), "unable to obtain RX DMA engine > channel %u\n", rx_req); > + goto err_irq; > + } > + > + host->tx_chan = dma_request_channel(mask, omap_dma_filter_fn, &tx_req); > + if (!host->tx_chan) { > + dev_err(mmc_dev(host->mmc), "unable to obtain TX DMA engine > channel %u\n", tx_req); > + goto err_irq; > } If either of these fails, ret is zero so even though this results in a failed probe, the return value (ret) is zero meaning the driver still gets bound to the device. The patch below fixes this and applies on your 'for-next' branch. Or, feel free to fold this into the original if you prefer. Kevin >From af7537997b46ee3991985fecd4b4a302bdc0df31 Mon Sep 17 00:00:00 2001 From: Kevin Hilman <[email protected]> Date: Tue, 10 Jul 2012 14:30:18 -0700 Subject: [PATCH] mmc: omap_hsmmc: ensure probe returns error if DMA channel request fails If dma_request_channel() fails (e.g. because DMA engine is not built into the kernel), the return value from probe is zero causing the driver to be bound to the device even though probe failed. To fix, ensure that probe returns an error value when a DMA channel request fail. Cc: Russell King <[email protected]> Signed-off-by: Kevin Hilman <[email protected]> --- drivers/mmc/host/omap_hsmmc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c index 2338703..ddcecf8 100644 --- a/drivers/mmc/host/omap_hsmmc.c +++ b/drivers/mmc/host/omap_hsmmc.c @@ -1924,12 +1924,14 @@ static int __devinit omap_hsmmc_probe(struct platform_device *pdev) host->rx_chan = dma_request_channel(mask, omap_dma_filter_fn, &rx_req); if (!host->rx_chan) { dev_err(mmc_dev(host->mmc), "unable to obtain RX DMA engine channel %u\n", rx_req); + ret = -ENXIO; goto err_irq; } host->tx_chan = dma_request_channel(mask, omap_dma_filter_fn, &tx_req); if (!host->tx_chan) { dev_err(mmc_dev(host->mmc), "unable to obtain TX DMA engine channel %u\n", tx_req); + ret -ENXIO; goto err_irq; } -- 1.7.9.2 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
