| Message ID | 1316516929-26694-1-git-send-email-girish.shivananjappa@linaro.org |
|---|---|
| State | New |
| Headers | show |
Hi, On Tue, Sep 20 2011, Girish K S wrote: > In the earlier code the cylinder, sector and head are assigned > independently. Current patch generates the cylinder number > with the values of sector and head. > This patch only makes they cylinder value to be dependent on > the sector and head. > > Signed-off-by: Girish K S <girish.shivananjappa@linaro.org> > --- > drivers/mmc/card/block.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c > index 1ff5486..bebb13b 100644 > --- a/drivers/mmc/card/block.c > +++ b/drivers/mmc/card/block.c > @@ -226,9 +226,10 @@ static int mmc_blk_release(struct gendisk *disk, fmode_t mode) > static int > mmc_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) > { > - geo->cylinders = get_capacity(bdev->bd_disk) / (4 * 16); > geo->heads = 4; > geo->sectors = 16; > + geo->cylinders = get_capacity(bdev->bd_disk) / > + (geo->heads * geo->sectors); > return 0; > } Thanks, pushed to mmc-next for 3.2 with a reworded commit message: Author: Girish K S <girish.shivananjappa@linaro.org> Date: Tue Sep 20 16:38:49 2011 +0530 mmc: card: Remove duplicated constants Reuse heads/sectors instead of duplicating them in the cylinders calculation. Signed-off-by: Girish K S <girish.shivananjappa@linaro.org> Signed-off-by: Chris Ball <cjb@laptop.org> - Chris.
Hello, On Wed, Sep 21, 2011 at 02:52:08PM -0400, Chris Ball wrote: > Hi, > > On Tue, Sep 20 2011, Girish K S wrote: > > In the earlier code the cylinder, sector and head are assigned > > independently. Current patch generates the cylinder number > > with the values of sector and head. > > This patch only makes they cylinder value to be dependent on > > the sector and head. > > > > Signed-off-by: Girish K S <girish.shivananjappa@linaro.org> > > --- > > drivers/mmc/card/block.c | 3 ++- > > 1 files changed, 2 insertions(+), 1 deletions(-) > > > > diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c > > index 1ff5486..bebb13b 100644 > > --- a/drivers/mmc/card/block.c > > +++ b/drivers/mmc/card/block.c > > @@ -226,9 +226,10 @@ static int mmc_blk_release(struct gendisk *disk, fmode_t mode) > > static int > > mmc_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) > > { > > - geo->cylinders = get_capacity(bdev->bd_disk) / (4 * 16); > > geo->heads = 4; > > geo->sectors = 16; > > + geo->cylinders = get_capacity(bdev->bd_disk) / > > + (geo->heads * geo->sectors); > > return 0; > > } > > Thanks, pushed to mmc-next for 3.2 with a reworded commit message: This (i.e. ee9e0e0 (mmc: card: Remove duplicated constants) in next) makes gcc emit a reference to __aeabi_uldivmod in one of my nightly builds which isn't defined. The final linking stage fails with: LD .tmp_vmlinux1 drivers/built-in.o: In function `mmc_blk_getgeo': clkdev.c:(.text+0xd1528): undefined reference to `__aeabi_uldivmod' make[2]: *** [.tmp_vmlinux1] Error 1 make[1]: *** [sub-make] Error 2 make: *** [all] Error 2 (I don't know why clkdev.c is referenced here. I'm not using ccache.) It seems gcc isn't smart enough to notice that it can just use the same generated code ... Having said that AFAIK the code used before wasn't ok, too. (I.e. an u64 division that was just noticed to be a shift by luck.) Best regards Uwe
Hi, On Mon, Sep 26 2011, Uwe Kleine-König wrote: >> Thanks, pushed to mmc-next for 3.2 with a reworded commit message: > This (i.e. ee9e0e0 (mmc: card: Remove duplicated constants) in next) > makes gcc emit a reference to __aeabi_uldivmod in one of my nightly > builds which isn't defined. > > The final linking stage fails with: > > LD .tmp_vmlinux1 > drivers/built-in.o: In function `mmc_blk_getgeo': > clkdev.c:(.text+0xd1528): undefined reference to `__aeabi_uldivmod' > make[2]: *** [.tmp_vmlinux1] Error 1 > make[1]: *** [sub-make] Error 2 > make: *** [all] Error 2 Interesting, thanks. It builds fine here on my (gcc-4.6) ARM toolchains. Looking online, I think you're hitting an old gcc-4.3 bug? - Chris.
On Mon, Sep 26, 2011 at 08:41:13AM -0400, Chris Ball wrote: > Hi, > > On Mon, Sep 26 2011, Uwe Kleine-König wrote: > >> Thanks, pushed to mmc-next for 3.2 with a reworded commit message: > > This (i.e. ee9e0e0 (mmc: card: Remove duplicated constants) in next) > > makes gcc emit a reference to __aeabi_uldivmod in one of my nightly > > builds which isn't defined. > > > > The final linking stage fails with: > > > > LD .tmp_vmlinux1 > > drivers/built-in.o: In function `mmc_blk_getgeo': > > clkdev.c:(.text+0xd1528): undefined reference to `__aeabi_uldivmod' > > make[2]: *** [.tmp_vmlinux1] Error 1 > > make[1]: *** [sub-make] Error 2 > > make: *** [all] Error 2 > > Interesting, thanks. It builds fine here on my (gcc-4.6) ARM toolchains. > Looking online, I think you're hitting an old gcc-4.3 bug? Yeah, this is gcc 4.3.2. Is it too old to be supported? Do you think of http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48783? Then no, that is not the problem. The function is actually used: 00000028 <mmc_blk_getgeo>: 28: e3a03004 mov r3, #4 2c: e3a02010 mov r2, #16 30: e92d4010 push {r4, lr} 34: e1a04001 mov r4, r1 38: e5c13000 strb r3, [r1] 3c: e5c12001 strb r2, [r1, #1] 40: e590c050 ldr ip, [r0, #80] ; 0x50 44: e3a02040 mov r2, #64 ; 0x40 48: e3a03000 mov r3, #0 4c: e1cc04d8 ldrd r0, [ip, #72] ; 0x48 50: ebfffffe bl 0 <__aeabi_uldivmod> 54: e1c400b2 strh r0, [r4, #2] 58: e3a00000 mov r0, #0 5c: e8bd8010 pop {r4, pc} I thought that the problem is more: > The kernel doesn't support 64-bit by 64-bit division at all then? Nope. 64-bit by 64-bit divides are grossly inefficient and should be avoided. (taken from http://www.spinics.net/lists/arm/msg13532.html) Best regards Uwe
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index 1ff5486..bebb13b 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -226,9 +226,10 @@ static int mmc_blk_release(struct gendisk *disk, fmode_t mode) static int mmc_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) { - geo->cylinders = get_capacity(bdev->bd_disk) / (4 * 16); geo->heads = 4; geo->sectors = 16; + geo->cylinders = get_capacity(bdev->bd_disk) / + (geo->heads * geo->sectors); return 0; }
In the earlier code the cylinder, sector and head are assigned independently. Current patch generates the cylinder number with the values of sector and head. This patch only makes they cylinder value to be dependent on the sector and head. Signed-off-by: Girish K S <girish.shivananjappa@linaro.org> --- drivers/mmc/card/block.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)