From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcin Slusarz Subject: Re: [PATCH] drm/nouveau/bios: fix DCB v1.5 parsing Date: Sat, 17 Nov 2012 21:33:15 +0100 Message-ID: <20121117203315.GA23587@joi.lan> References: <20121115210914.GA6970@joi.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nouveau-bounces+gcfxn-nouveau=m.gmane.org-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org Errors-To: nouveau-bounces+gcfxn-nouveau=m.gmane.org-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org To: Dave Airlie Cc: nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org List-Id: nouveau.vger.kernel.org On Fri, Nov 16, 2012 at 09:36:56PM +1000, Dave Airlie wrote: > On Fri, Nov 16, 2012 at 7:09 AM, Marcin Slusarz > wrote: > > memcmp->nv_strncmp conversion should have inverted the return value. > > > > Signed-off-by: Marcin Slusarz > > --- > > See http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=blob;f=drivers/gpu/drm/nouveau/nouveau_bios.c;h=a0a3fe3c016be86665db1369c44bef832f829a1a;hb=a0d271cbfed1dd50278c6b06bead3d00ba0a88f9#l5652 (3.6) > > and http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=blob;f=drivers/gpu/drm/nouveau/core/include/core/object.h;h=818feabbf4a0969f090f897852fe4476a422b1b6;hb=77b67063bb6bce6d475e910d3b886a606d0d91f7#l179 (nv_strncmp definition) > > Christ fix that nv_strncmp to act like the C one, or give it a very > different name! Please don't kill the messenger. --- From: Marcin Slusarz Subject: [PATCH v2] drm/nouveau/bios: fix DCB v1.5 parsing memcmp->nv_strncmp conversion, in addition to name change, should have inverted the return value. But nv_strncmp does not act like strncmp - it does not check for string terminator, returns true/false instead of -1/0/1 and has different parameters order. Let's rename it to nv_memcmp and let it act like memcmp. Signed-off-by: Marcin Slusarz --- drivers/gpu/drm/nouveau/core/include/core/object.h | 14 +++++++++----- drivers/gpu/drm/nouveau/core/subdev/bios/dcb.c | 2 +- 2 files changed, 10 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/nouveau/core/include/core/object.h b/drivers/gpu/drm/nouveau/core/include/core/object.h index 818feab..486f1a9 100644 --- a/drivers/gpu/drm/nouveau/core/include/core/object.h +++ b/drivers/gpu/drm/nouveau/core/include/core/object.h @@ -175,14 +175,18 @@ nv_mo32(void *obj, u32 addr, u32 mask, u32 data) return temp; } -static inline bool -nv_strncmp(void *obj, u32 addr, u32 len, const char *str) +static inline int +nv_memcmp(void *obj, u32 addr, const char *str, u32 len) { + unsigned char c1, c2; + while (len--) { - if (nv_ro08(obj, addr++) != *(str++)) - return false; + c1 = nv_ro08(obj, addr++); + c2 = *(str++); + if (c1 != c2) + return c1 - c2; } - return true; + return 0; } #endif diff --git a/drivers/gpu/drm/nouveau/core/subdev/bios/dcb.c b/drivers/gpu/drm/nouveau/core/subdev/bios/dcb.c index 7d75038..c511971 100644 --- a/drivers/gpu/drm/nouveau/core/subdev/bios/dcb.c +++ b/drivers/gpu/drm/nouveau/core/subdev/bios/dcb.c @@ -64,7 +64,7 @@ dcb_table(struct nouveau_bios *bios, u8 *ver, u8 *hdr, u8 *cnt, u8 *len) } } else if (*ver >= 0x15) { - if (!nv_strncmp(bios, dcb - 7, 7, "DEV_REC")) { + if (!nv_memcmp(bios, dcb - 7, "DEV_REC", 7)) { u16 i2c = nv_ro16(bios, dcb + 2); *hdr = 4; *cnt = (i2c - dcb) / 10; -- 1.7.12