Messages in this thread | | | Date | Wed, 30 Jan 2013 09:21:28 +0100 | From | walter harms <> | Subject | Re: coccinelle and bitmask arithmetic |
| |
Am 29.01.2013 19:03, schrieb Joe Perches: > On Tue, 2013-01-29 at 18:49 +0100, Julia Lawall wrote: >> How about the following (from today's linux-next). They appear to be >> trying to do the same calculation, once with + and once with |. > > (cc'ing the original developer and Russell King) > > Likely the it8152_pci_platform_notify uses should use + > >> arch/arm/common/it8152.c >> >> int dma_set_coherent_mask(struct device *dev, u64 mask) >> { >> if (mask >= PHYS_OFFSET + SZ_64M - 1) >> return 0; >> >> return -EIO; >> } >>
Great hit Joe :)
Sometimes i am really surprised what code can be found in the kernal and it is still working. Having no clue of the code i suspect somebody tries to check is mask outside the range it should read PHYS_OFFSET |( SZ_64M - 1) maybe someone should tell them that 1+1=10 while 1|1=1 It does not seem to matter here (or ... ?)
really perplexed,
wh
>> static int it8152_pci_platform_notify(struct device *dev) >> { >> if (dev->bus == &pci_bus_type) { >> if (dev->dma_mask) >> *dev->dma_mask = (SZ_64M - 1) | PHYS_OFFSET; >> dev->coherent_dma_mask = (SZ_64M - 1) | PHYS_OFFSET; >> dmabounce_register_dev(dev, 2048, 4096, it8152_needs_bounce); >> } >> return 0; >> } > > > -- > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > >
| |