From mboxrd@z Thu Jan 1 00:00:00 1970 From: walter harms Date: Wed, 30 Jan 2013 08:21:28 +0000 Subject: Re: coccinelle and bitmask arithmetic Message-Id: <5108D808.6010405@bfs.de> List-Id: References: <20130127194039.GA18787@elgon.mountain> <1359317078.14406.12.camel@joe-AO722> <20130127201947.GO16282@mwanda> <9561.1359474916@turing-police.cc.vt.edu> <1359475998.4196.26.camel@joe-AO722> <1359482637.15135.7.camel@joe-AO722> In-Reply-To: <1359482637.15135.7.camel@joe-AO722> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: cocci@systeme.lip6.fr 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 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 > >