From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.bootlin.com ([62.4.15.54]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fdEnp-0007an-Vs for linux-mtd@lists.infradead.org; Wed, 11 Jul 2018 13:05:19 +0000 Date: Wed, 11 Jul 2018 15:04:49 +0200 From: Boris Brezillon To: Arnd Bergmann Cc: Miquel Raynal , David Woodhouse , Brian Norris , Marek Vasut , Richard Weinberger , Abhishek Sahu , Archit Taneja , Masahiro Yamada , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] nand: ranw: qcom_nand: stop using phys_to_dma() Message-ID: <20180711150449.4152333c@bbrezillon> In-Reply-To: <20180711122709.358159-1-arnd@arndb.de> References: <20180711122709.358159-1-arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 11 Jul 2018 14:26:58 +0200 Arnd Bergmann wrote: > Compile-testing this driver on x86 caused a link error: > > ERROR: "__phys_to_dma" [drivers/mtd/nand/raw/qcom_nandc.ko] undefined! > > The problem here is that the driver attempts to convert the physical > address into the DMA controller as a dma_addr_t and calls phys_to_dma() > to do the conversion. > > However, there is no generic way to convert a phys_addr_t into a dma_addr_t > for anything other than RAM (which should use the dma-mapping API instead). > The only correct use of phys_to_dma() instead is inside of the dma-mapping > implementation. Should we use dma_map_resource() to do the phys_addr_t to dma_addr_t conversion? > > In all other drivers that deal with DMA FIFO addresses, we just pass the > physical address directly and have the DMA controller deal with that > if necessary, so let's do the same thing here. > > Fixes: c76b78d8ec05 ("mtd: nand: Qualcomm NAND controller driver") > Signed-off-by: Arnd Bergmann > --- > drivers/mtd/nand/raw/qcom_nandc.c | 7 ++----- > 1 file changed, 2 insertions(+), 5 deletions(-) > > diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c > index 994f980c6d86..f047e2819041 100644 > --- a/drivers/mtd/nand/raw/qcom_nandc.c > +++ b/drivers/mtd/nand/raw/qcom_nandc.c > @@ -338,7 +338,6 @@ struct nandc_regs { > * @dev: parent device > * @base: MMIO base > * @base_phys: physical base address of controller registers > - * @base_dma: dma base address of controller registers > * @core_clk: controller clock > * @aon_clk: another controller clock > * > @@ -372,7 +371,6 @@ struct qcom_nand_controller { > > void __iomem *base; > phys_addr_t base_phys; > - dma_addr_t base_dma; > > struct clk *core_clk; > struct clk *aon_clk; > @@ -935,11 +933,11 @@ static int prep_adm_dma_desc(struct qcom_nand_controller *nandc, bool read, > slave_conf.device_fc = flow_control; > if (read) { > slave_conf.src_maxburst = 16; > - slave_conf.src_addr = nandc->base_dma + reg_off; > + slave_conf.src_addr = (dma_addr_t)nandc->base_phys + reg_off; > slave_conf.slave_id = nandc->data_crci; > } else { > slave_conf.dst_maxburst = 16; > - slave_conf.dst_addr = nandc->base_dma + reg_off; > + slave_conf.dst_addr = (dma_addr_t)nandc->base_phys + reg_off; > slave_conf.slave_id = nandc->cmd_crci; > } > > @@ -2963,7 +2961,6 @@ static int qcom_nandc_probe(struct platform_device *pdev) > return PTR_ERR(nandc->base); > > nandc->base_phys = res->start; > - nandc->base_dma = phys_to_dma(dev, (phys_addr_t)res->start); > > nandc->core_clk = devm_clk_get(dev, "core"); > if (IS_ERR(nandc->core_clk))