| Message ID | 1389024157-19279-1-git-send-email-denis@eukrea.com |
|---|---|
| State | Changes Requested |
| Headers | show |
On Mon, Jan 06, 2014 at 05:02:36PM +0100, Denis Carikli wrote: > The linux/mtd/mtd.h header has a comment in the > mtd_info struct definition that says that > having a writesize of 0 is illegal. > > When nand_flash_detect_onfi is called (in the case > of an ONFI flash), it will call the function > pointed by read_buf in order to get some parameters > of the flash chip, including its writesize. Note that (for fixing buswidth issues when using x16 vs. x8) nand_flash_detect_onfi() no longer uses read_buf(). So this shouldn't actually be an issue any more, I don't think. But we still might want to set some value, due to the strange implementation of read_buf() in this driver. > Before decoding the writesize value that was retrived > with that read, the mxc_nand's mtd_info struct had > a writesize set to zero. > > Cc: David Woodhouse <dwmw2@infradead.org> > Cc: linux-mtd@lists.infradead.org > Cc: Sascha Hauer <s.hauer@pengutronix.de> > Cc: Eric Bénard <eric@eukrea.com> > Signed-off-by: Denis Carikli <denis@eukrea.com> > --- > ChangeLog v2->v3: > New patch in this serie. > --- > drivers/mtd/nand/mxc_nand.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c > index 567a5e5..d4d8d66 100644 > --- a/drivers/mtd/nand/mxc_nand.c > +++ b/drivers/mtd/nand/mxc_nand.c > @@ -1415,6 +1415,9 @@ static int mxcnd_probe(struct platform_device *pdev) > mtd->dev.parent = &pdev->dev; > mtd->name = DRIVER_NAME; > > + /* Enforce a minimum writesize */ > + mtd->writesize = 512; > + Is this "initial" writesize just needed for the bounds checking in read_buf() (and write_buf())? Then wouldn't it make sense to match the buffer size allocated initially? See: /* allocate a temporary buffer for the nand_scan_ident() */ host->data_buf = devm_kzalloc(&pdev->dev, PAGE_SIZE, GFP_KERNEL); Also, I don't think you actually need the bounds checks in read_buf()/write_buf(), although I guess there's no real harm... > /* 50 us command delay time */ > this->chip_delay = 5; > Brian
diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c index 567a5e5..d4d8d66 100644 --- a/drivers/mtd/nand/mxc_nand.c +++ b/drivers/mtd/nand/mxc_nand.c @@ -1415,6 +1415,9 @@ static int mxcnd_probe(struct platform_device *pdev) mtd->dev.parent = &pdev->dev; mtd->name = DRIVER_NAME; + /* Enforce a minimum writesize */ + mtd->writesize = 512; + /* 50 us command delay time */ this->chip_delay = 5;
The linux/mtd/mtd.h header has a comment in the mtd_info struct definition that says that having a writesize of 0 is illegal. When nand_flash_detect_onfi is called (in the case of an ONFI flash), it will call the function pointed by read_buf in order to get some parameters of the flash chip, including its writesize. Before decoding the writesize value that was retrived with that read, the mxc_nand's mtd_info struct had a writesize set to zero. Cc: David Woodhouse <dwmw2@infradead.org> Cc: linux-mtd@lists.infradead.org Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Eric Bénard <eric@eukrea.com> Signed-off-by: Denis Carikli <denis@eukrea.com> --- ChangeLog v2->v3: New patch in this serie. --- drivers/mtd/nand/mxc_nand.c | 3 +++ 1 file changed, 3 insertions(+)