From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.free-electrons.com ([62.4.15.54]) by bombadil.infradead.org with esmtp (Exim 4.89 #1 (Red Hat Linux)) id 1eZPGK-0004fl-6x for linux-mtd@lists.infradead.org; Wed, 10 Jan 2018 22:54:26 +0000 Date: Wed, 10 Jan 2018 23:54:01 +0100 From: Boris Brezillon To: Han Xu Cc: Frank Li , "linux-mtd@lists.infradead.org" , "cyrille.pitchen@wedev4u.fr" , Fabio Estevam , David Wolfe , Fabio Estevam Subject: Re: [PATCH] mtd: fsl-quadspi: Distinguish the mtd device names Message-ID: <20180110235401.724d6665@bbrezillon> In-Reply-To: <20180110231719.72767797@bbrezillon> References: <1515181560-1410-1-git-send-email-festevam@gmail.com> <20180110231719.72767797@bbrezillon> 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, 10 Jan 2018 23:17:19 +0100 Boris Brezillon wrote: > On Mon, 8 Jan 2018 17:13:17 +0000 > Han Xu wrote: > > > ________________________________________ > > From: Fabio Estevam > > Sent: Friday, January 5, 2018 1:46 PM > > To: Han Xu > > Cc: cyrille.pitchen@wedev4u.fr; David Wolfe; Frank Li; linux-mtd@lists.infradead.org; Fabio Estevam > > Subject: [PATCH] mtd: fsl-quadspi: Distinguish the mtd device names > > > > From: Fabio Estevam > > > > Currently on a imx6sx-sdb board, which has two SPI NOR chips connected > > to QSPI2 the following output from /proc/mtd is seen: > > > > # cat /proc/mtd > > dev: size erasesize name > > mtd0: 01000000 00010000 "21e4000.qspi" > > mtd1: 01000000 00010000 "21e4000.qspi" > > > > Attempts to partition them on the kernel command line result in both > > chips with identical (and identically named) partitions, which is > > an inconvenient behavior. > > > > Assign a different mtd->name for each mtd device to avoid this problem. > > > > After this change the output from /proc/mtd becomes: > > > > # cat /proc/mtd > > dev: size erasesize name > > mtd0: 01000000 00010000 "fsl-quadspi.0" > > mtd1: 01000000 00010000 "fsl-quadspi.1" > > What happens if you end up having 2 qspi IPs in the same SoC? IMHO, > it's more future proof to have something like > ".qspi:" or ".qspi:". > > > > > Reported-by: David Wolfe > > Signed-off-by: Fabio Estevam > > --- > > drivers/mtd/spi-nor/fsl-quadspi.c | 10 +++++++++- > > 1 file changed, 9 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c > > index f17d224..7712c63 100644 > > --- a/drivers/mtd/spi-nor/fsl-quadspi.c > > +++ b/drivers/mtd/spi-nor/fsl-quadspi.c > > @@ -967,7 +967,7 @@ static int fsl_qspi_probe(struct platform_device *pdev) > > struct resource *res; > > struct spi_nor *nor; > > struct mtd_info *mtd; > > - int ret, i = 0; > > + int ret, i = 0, mtd_index = 0; > > It's not the MTD index if you have other MTD devices. How about > spiflash_idx? > > > > > q = devm_kzalloc(dev, sizeof(*q), GFP_KERNEL); > > if (!q) > > @@ -1047,6 +1047,13 @@ static int fsl_qspi_probe(struct platform_device *pdev) > > nor = &q->nor[i]; > > mtd = &nor->mtd; > > > > + mtd->name = devm_kasprintf(dev, GFP_KERNEL, "fsl-quadspi.%d", > > + mtd_index); > > With the alternative naming scheme suggested above, it gives: > > mtd->name = devm_kasprintf(dev, GFP_KERNEL, "%s:%d" > dev_name(&pdev->dev), > mtd_index); > > > + if (!mtd->name) { > > + ret = -ENOMEM; > > + goto mutex_failed; > > + } > > + > > nor->dev = dev; > > spi_nor_set_flash_node(nor, np); One, last thing: there's a generic mechanism using the value of the 'label' property for mtd->name, which is particularly useful if one wants to assign user-friendly names to his flashes. This is done in spi_nor_set_flash_node() (more precisely in mtd_set_of_node() which is called by spi_nor_set_flash_node()), but it only works if mtd->name is NULL. So I recommend move the mtd->name assignment here, and making it conditional: if (!mtd->name) { mtd->name = devm_kasprintf(...); ... } > > nor->priv = q; > > @@ -1098,6 +1105,7 @@ static int fsl_qspi_probe(struct platform_device *pdev) > > nor->page_size = q->devtype_data->txfifo; > > > > i++; > > + mtd_index++; > > } > > > > /* finish the rest init. */ > > -- > > 2.7.4 > > > > Acked-by: Han Xu > > > > ______________________________________________________ > > Linux MTD discussion mailing list > > http://lists.infradead.org/mailman/listinfo/linux-mtd/ > > > ______________________________________________________ > Linux MTD discussion mailing list > http://lists.infradead.org/mailman/listinfo/linux-mtd/