| Message ID | 1449842554-29898-1-git-send-email-boris.brezillon@free-electrons.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
+ Dinh (who made commit 2a0a288ec258) Also added back the Fixes tag. On Fri, 11 Dec 2015 15:02:34 +0100 Boris Brezillon <boris.brezillon@free-electrons.com> wrote: > Unregister the NAND device from the NAND subsystem when removing a denali > NAND controller, otherwise the MTD attached to the NAND device is still > exposed by the MTD layer, and accesses to this device will likely crash > the system. > > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Fixes: 2a0a288ec258 ("mtd: denali: split the generic driver and PCI layer") > --- > Changes since v4: > - remove Cc stable and fixes tags > - calculate the dma buffer size before calling nand_release() > > drivers/mtd/nand/denali.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c > index 67eb2be..fdfea05 100644 > --- a/drivers/mtd/nand/denali.c > +++ b/drivers/mtd/nand/denali.c > @@ -1622,9 +1622,11 @@ EXPORT_SYMBOL(denali_init); > /* driver exit point */ > void denali_remove(struct denali_nand_info *denali) > { > + int bufsize = denali->mtd.writesize + denali->mtd.oobsize; > + > + nand_release(&denali->mtd); > denali_irq_cleanup(denali->irq, denali); > - dma_unmap_single(denali->dev, denali->buf.dma_buf, > - denali->mtd.writesize + denali->mtd.oobsize, > + dma_unmap_single(denali->dev, denali->buf.dma_buf, bufsize, > DMA_BIDIRECTIONAL); > } > EXPORT_SYMBOL(denali_remove);
Hi Boris, On Fri, Dec 11, 2015 at 9:10 AM, Boris Brezillon <boris.brezillon@free-electrons.com> wrote: > + Dinh (who made commit 2a0a288ec258) > > Also added back the Fixes tag. > > On Fri, 11 Dec 2015 15:02:34 +0100 > Boris Brezillon <boris.brezillon@free-electrons.com> wrote: > >> Unregister the NAND device from the NAND subsystem when removing a denali >> NAND controller, otherwise the MTD attached to the NAND device is still >> exposed by the MTD layer, and accesses to this device will likely crash >> the system. >> >> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> > > Fixes: 2a0a288ec258 ("mtd: denali: split the generic driver and PCI layer") > >> --- >> Changes since v4: >> - remove Cc stable and fixes tags >> - calculate the dma buffer size before calling nand_release() >> >> drivers/mtd/nand/denali.c | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c >> index 67eb2be..fdfea05 100644 >> --- a/drivers/mtd/nand/denali.c >> +++ b/drivers/mtd/nand/denali.c >> @@ -1622,9 +1622,11 @@ EXPORT_SYMBOL(denali_init); >> /* driver exit point */ >> void denali_remove(struct denali_nand_info *denali) >> { >> + int bufsize = denali->mtd.writesize + denali->mtd.oobsize; >> + >> + nand_release(&denali->mtd); >> denali_irq_cleanup(denali->irq, denali); >> - dma_unmap_single(denali->dev, denali->buf.dma_buf, >> - denali->mtd.writesize + denali->mtd.oobsize, >> + dma_unmap_single(denali->dev, denali->buf.dma_buf, bufsize, >> DMA_BIDIRECTIONAL); Not sure what is the need to add bufsize here, but the commit message doesn't reflect the change. Dinh -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Dinh, On Fri, 11 Dec 2015 10:50:21 -0600 Dinh Nguyen <dinh.linux@gmail.com> wrote: > Hi Boris, > > On Fri, Dec 11, 2015 at 9:10 AM, Boris Brezillon > <boris.brezillon@free-electrons.com> wrote: > > + Dinh (who made commit 2a0a288ec258) > > > > Also added back the Fixes tag. > > > > On Fri, 11 Dec 2015 15:02:34 +0100 > > Boris Brezillon <boris.brezillon@free-electrons.com> wrote: > > > >> Unregister the NAND device from the NAND subsystem when removing a denali > >> NAND controller, otherwise the MTD attached to the NAND device is still > >> exposed by the MTD layer, and accesses to this device will likely crash > >> the system. > >> > >> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> > > > > Fixes: 2a0a288ec258 ("mtd: denali: split the generic driver and PCI layer") > > > >> --- > >> Changes since v4: > >> - remove Cc stable and fixes tags > >> - calculate the dma buffer size before calling nand_release() > >> > >> drivers/mtd/nand/denali.c | 6 ++++-- > >> 1 file changed, 4 insertions(+), 2 deletions(-) > >> > >> diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c > >> index 67eb2be..fdfea05 100644 > >> --- a/drivers/mtd/nand/denali.c > >> +++ b/drivers/mtd/nand/denali.c > >> @@ -1622,9 +1622,11 @@ EXPORT_SYMBOL(denali_init); > >> /* driver exit point */ > >> void denali_remove(struct denali_nand_info *denali) > >> { > >> + int bufsize = denali->mtd.writesize + denali->mtd.oobsize; > >> + > >> + nand_release(&denali->mtd); > >> denali_irq_cleanup(denali->irq, denali); > >> - dma_unmap_single(denali->dev, denali->buf.dma_buf, > >> - denali->mtd.writesize + denali->mtd.oobsize, > >> + dma_unmap_single(denali->dev, denali->buf.dma_buf, bufsize, > >> DMA_BIDIRECTIONAL); > > Not sure what is the need to add bufsize here, but the commit message > doesn't reflect the change. You were not in Cc of the first version (my fault), but Brian pointed that the mtd fields could be in an unknown state after the nand_release() call (this is currently not the case, but it change in the future). The idea is to pre-compute the DMA buffer size before releasing the mtd/nand device to prevent any future issues. I don't think it is worth mentioning this in the commit message, because these are just implementation details, but I can add the following comment before the bufsize declaration: /* * Pre-compute DMA buffer size to avoid any problems in case * nand_release() ever changes in a way that mtd->writesize and * mtd->oobsize are not reliable after this call. */ What do you think? Best Regards, Boris > > Dinh
On Fri, Dec 11, 2015 at 11:08 AM, Boris Brezillon <boris.brezillon@free-electrons.com> wrote: > Hi Dinh, > > On Fri, 11 Dec 2015 10:50:21 -0600 > Dinh Nguyen <dinh.linux@gmail.com> wrote: > >> Hi Boris, >> >> On Fri, Dec 11, 2015 at 9:10 AM, Boris Brezillon >> <boris.brezillon@free-electrons.com> wrote: >> > + Dinh (who made commit 2a0a288ec258) >> > >> > Also added back the Fixes tag. >> > >> > On Fri, 11 Dec 2015 15:02:34 +0100 >> > Boris Brezillon <boris.brezillon@free-electrons.com> wrote: >> > >> >> Unregister the NAND device from the NAND subsystem when removing a denali >> >> NAND controller, otherwise the MTD attached to the NAND device is still >> >> exposed by the MTD layer, and accesses to this device will likely crash >> >> the system. >> >> >> >> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> >> > >> > Fixes: 2a0a288ec258 ("mtd: denali: split the generic driver and PCI layer") >> > >> >> --- >> >> Changes since v4: >> >> - remove Cc stable and fixes tags >> >> - calculate the dma buffer size before calling nand_release() >> >> >> >> drivers/mtd/nand/denali.c | 6 ++++-- >> >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> >> >> diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c >> >> index 67eb2be..fdfea05 100644 >> >> --- a/drivers/mtd/nand/denali.c >> >> +++ b/drivers/mtd/nand/denali.c >> >> @@ -1622,9 +1622,11 @@ EXPORT_SYMBOL(denali_init); >> >> /* driver exit point */ >> >> void denali_remove(struct denali_nand_info *denali) >> >> { >> >> + int bufsize = denali->mtd.writesize + denali->mtd.oobsize; >> >> + >> >> + nand_release(&denali->mtd); >> >> denali_irq_cleanup(denali->irq, denali); >> >> - dma_unmap_single(denali->dev, denali->buf.dma_buf, >> >> - denali->mtd.writesize + denali->mtd.oobsize, >> >> + dma_unmap_single(denali->dev, denali->buf.dma_buf, bufsize, >> >> DMA_BIDIRECTIONAL); >> >> Not sure what is the need to add bufsize here, but the commit message >> doesn't reflect the change. > > You were not in Cc of the first version (my fault), but Brian pointed > that the mtd fields could be in an unknown state after the > nand_release() call (this is currently not the case, but it change in > the future). The idea is to pre-compute the DMA buffer size before > releasing the mtd/nand device to prevent any future issues. > > I don't think it is worth mentioning this in the commit message, > because these are just implementation details, but I can add the > following comment before the bufsize declaration: > > /* > * Pre-compute DMA buffer size to avoid any problems in case > * nand_release() ever changes in a way that mtd->writesize and > * mtd->oobsize are not reliable after this call. > */ > > What do you think? > Ah, perfect! With the updated comment, Acked-by: Dinh Nguyen <dinguyen@opensource.altera.com> Thanks, Dinh -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c index 67eb2be..fdfea05 100644 --- a/drivers/mtd/nand/denali.c +++ b/drivers/mtd/nand/denali.c @@ -1622,9 +1622,11 @@ EXPORT_SYMBOL(denali_init); /* driver exit point */ void denali_remove(struct denali_nand_info *denali) { + int bufsize = denali->mtd.writesize + denali->mtd.oobsize; + + nand_release(&denali->mtd); denali_irq_cleanup(denali->irq, denali); - dma_unmap_single(denali->dev, denali->buf.dma_buf, - denali->mtd.writesize + denali->mtd.oobsize, + dma_unmap_single(denali->dev, denali->buf.dma_buf, bufsize, DMA_BIDIRECTIONAL); } EXPORT_SYMBOL(denali_remove);
Unregister the NAND device from the NAND subsystem when removing a denali NAND controller, otherwise the MTD attached to the NAND device is still exposed by the MTD layer, and accesses to this device will likely crash the system. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> --- Changes since v4: - remove Cc stable and fixes tags - calculate the dma buffer size before calling nand_release() drivers/mtd/nand/denali.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)