| Message ID | 1423049774-16305-1-git-send-email-hofrat@osadl.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, 4 Feb 2015, Nicholas Mc Guire wrote: > The if and the else branch code are identical - so the condition has no > effect on the effective code - this patch removes the condition and the > duplicated code. > > Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> > --- > > This code has been in here since commit 544393fe584d ("sisfb update") so I guess it is > safe to simply remove the duplicated code if nobody noticed for 10 years. > > Note that the code is not really CodingStyle compliant - the lines inserted were formatted > to satisfy the coding style but I'm unsure if it is not better to leave it in the > old format. > > Patch was only compile tested with x86_64_defconfig + > CONFIG_FB_SIS=m, CONFIG_FB_SIS_300=y, CONFIG_FB_SIS_315=y > > Patch is against 3.19.0-rc7 (localversion-next is -next-20150204) > > drivers/video/fbdev/sis/init301.c | 9 ++------- > 1 file changed, 2 insertions(+), 7 deletions(-) > > diff --git a/drivers/video/fbdev/sis/init301.c b/drivers/video/fbdev/sis/init301.c > index 295e0de..9533a8ab 100644 > --- a/drivers/video/fbdev/sis/init301.c > +++ b/drivers/video/fbdev/sis/init301.c > @@ -7971,13 +7971,8 @@ SiS_SetCHTVReg(struct SiS_Private *SiS_Pr, unsigned short ModeNo, unsigned short > } > } else { /* ---- PAL ---- */ > /* We don't play around with FSCI in PAL mode */ > - if(resindex == 0x04) { > - SiS_SetCH70xxANDOR(SiS_Pr,0x20,0x00,0xEF); /* loop filter off */ > - SiS_SetCH70xxANDOR(SiS_Pr,0x21,0x01,0xFE); /* ACIV on */ > - } else { > - SiS_SetCH70xxANDOR(SiS_Pr,0x20,0x00,0xEF); /* loop filter off */ > - SiS_SetCH70xxANDOR(SiS_Pr,0x21,0x01,0xFE); /* ACIV on */ > - } > + SiS_SetCH70xxANDOR(SiS_Pr, 0x20, 0x00, 0xEF); /* loop filter off */ > + SiS_SetCH70xxANDOR(SiS_Pr, 0x21, 0x01, 0xFE); /* ACIV on */ > } > > #endif /* 300 */ The code covering the PAL case had this redundancy when it was introduced in Linux 2.4.19. Lines 7934-7981 consider three variables: PAL, overscan, and resindex. Given the "#ifdef 0" block, couldn't the current six sections collapse into two? One for (!PAL && overscan && resindex==5) and another for the rest? -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Feb 5, 2015 at 9:45 PM, Scot Doyle wrote: > On Wed, 4 Feb 2015, Nicholas Mc Guire wrote: >> The if and the else branch code are identical - so the condition has no >> effect on the effective code - this patch removes the condition and the >> duplicated code. >> >> Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> >> --- >> >> This code has been in here since commit 544393fe584d ("sisfb update") so I guess it is >> safe to simply remove the duplicated code if nobody noticed for 10 years. >> >> Note that the code is not really CodingStyle compliant - the lines inserted were formatted >> to satisfy the coding style but I'm unsure if it is not better to leave it in the >> old format. >> >> Patch was only compile tested with x86_64_defconfig + >> CONFIG_FB_SIS=m, CONFIG_FB_SIS_300=y, CONFIG_FB_SIS_315=y >> >> Patch is against 3.19.0-rc7 (localversion-next is -next-20150204) >> >> drivers/video/fbdev/sis/init301.c | 9 ++------- >> 1 file changed, 2 insertions(+), 7 deletions(-) >> >> diff --git a/drivers/video/fbdev/sis/init301.c b/drivers/video/fbdev/sis/init301.c >> index 295e0de..9533a8ab 100644 >> --- a/drivers/video/fbdev/sis/init301.c >> +++ b/drivers/video/fbdev/sis/init301.c >> @@ -7971,13 +7971,8 @@ SiS_SetCHTVReg(struct SiS_Private *SiS_Pr, unsigned short ModeNo, unsigned short >> } >> } else { /* ---- PAL ---- */ >> /* We don't play around with FSCI in PAL mode */ >> - if(resindex == 0x04) { >> - SiS_SetCH70xxANDOR(SiS_Pr,0x20,0x00,0xEF); /* loop filter off */ >> - SiS_SetCH70xxANDOR(SiS_Pr,0x21,0x01,0xFE); /* ACIV on */ >> - } else { >> - SiS_SetCH70xxANDOR(SiS_Pr,0x20,0x00,0xEF); /* loop filter off */ >> - SiS_SetCH70xxANDOR(SiS_Pr,0x21,0x01,0xFE); /* ACIV on */ >> - } >> + SiS_SetCH70xxANDOR(SiS_Pr, 0x20, 0x00, 0xEF); /* loop filter off */ >> + SiS_SetCH70xxANDOR(SiS_Pr, 0x21, 0x01, 0xFE); /* ACIV on */ >> } >> >> #endif /* 300 */ > > The code covering the PAL case had this redundancy when it was introduced > in Linux 2.4.19. > > Lines 7934-7981 consider three variables: PAL, overscan, and resindex. > Given the "#ifdef 0" block, couldn't the current six sections collapse > into two? One for (!PAL && overscan && resindex==5) and another for the > rest? Are we sure there isn't a typo in one of the duplicate clauses? Or wrong copy-pasting? Generally I am skeptical to "fixing" code without understanding what is behind or testing it, and just cosmetically brush over it. For now at least it is obvious that there is something wrong. In case (although an unlikely one) someone who understands the code and knows this chip comes along, he would quickly spot this. After your "fixups" this will be all forgotten. Additionally it adds to the impression that this code is being maintained, which is wrong. I would understand an argument about annoying compiler warnings and the like, but in that case I would prefer to #if 0 it instead of "prettifying" it. 0.02 Tormod -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 5 Feb 2015, Tormod Volden wrote: > On Thu, Feb 5, 2015 at 9:45 PM, Scot Doyle wrote: > > On Wed, 4 Feb 2015, Nicholas Mc Guire wrote: > >> The if and the else branch code are identical - so the condition has no > >> effect on the effective code - this patch removes the condition and the > >> duplicated code. > >> > >> Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> > >> --- > >> > >> This code has been in here since commit 544393fe584d ("sisfb update") so I guess it is > >> safe to simply remove the duplicated code if nobody noticed for 10 years. > >> > >> Note that the code is not really CodingStyle compliant - the lines inserted were formatted > >> to satisfy the coding style but I'm unsure if it is not better to leave it in the > >> old format. > >> > >> Patch was only compile tested with x86_64_defconfig + > >> CONFIG_FB_SIS=m, CONFIG_FB_SIS_300=y, CONFIG_FB_SIS_315=y > >> > >> Patch is against 3.19.0-rc7 (localversion-next is -next-20150204) > >> > >> drivers/video/fbdev/sis/init301.c | 9 ++------- > >> 1 file changed, 2 insertions(+), 7 deletions(-) > >> > >> diff --git a/drivers/video/fbdev/sis/init301.c b/drivers/video/fbdev/sis/init301.c > >> index 295e0de..9533a8ab 100644 > >> --- a/drivers/video/fbdev/sis/init301.c > >> +++ b/drivers/video/fbdev/sis/init301.c > >> @@ -7971,13 +7971,8 @@ SiS_SetCHTVReg(struct SiS_Private *SiS_Pr, unsigned short ModeNo, unsigned short > >> } > >> } else { /* ---- PAL ---- */ > >> /* We don't play around with FSCI in PAL mode */ > >> - if(resindex == 0x04) { > >> - SiS_SetCH70xxANDOR(SiS_Pr,0x20,0x00,0xEF); /* loop filter off */ > >> - SiS_SetCH70xxANDOR(SiS_Pr,0x21,0x01,0xFE); /* ACIV on */ > >> - } else { > >> - SiS_SetCH70xxANDOR(SiS_Pr,0x20,0x00,0xEF); /* loop filter off */ > >> - SiS_SetCH70xxANDOR(SiS_Pr,0x21,0x01,0xFE); /* ACIV on */ > >> - } > >> + SiS_SetCH70xxANDOR(SiS_Pr, 0x20, 0x00, 0xEF); /* loop filter off */ > >> + SiS_SetCH70xxANDOR(SiS_Pr, 0x21, 0x01, 0xFE); /* ACIV on */ > >> } > >> > >> #endif /* 300 */ > > > > The code covering the PAL case had this redundancy when it was introduced > > in Linux 2.4.19. > > > > Lines 7934-7981 consider three variables: PAL, overscan, and resindex. > > Given the "#ifdef 0" block, couldn't the current six sections collapse > > into two? One for (!PAL && overscan && resindex==5) and another for the > > rest? > > Are we sure there isn't a typo in one of the duplicate clauses? Or > wrong copy-pasting? Generally I am skeptical to "fixing" code without > understanding what is behind or testing it, and just cosmetically > brush over it. For now at least it is obvious that there is something > wrong. In case (although an unlikely one) someone who understands the > code and knows this chip comes along, he would quickly spot this. > After your "fixups" this will be all forgotten. Additionally it adds > to the impression that this code is being maintained, which is wrong. > > I would understand an argument about annoying compiler warnings and > the like, but in that case I would prefer to #if 0 it instead of > "prettifying" it. > > 0.02 > Tormod Yes, I also wondered how this code came to be. The general intention of the code seems clear from the code comments and the diff between 2.4.18 and 2.4.19. The redundancy pointed out in the patch existed in the !PAL case, and became obvious when copied and reduced to the PAL case. Thanks for pointing out that it hasn't been maintained, I missed that. -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Tormod Volden wrote: > On Thu, Feb 5, 2015 at 9:45 PM, Scot Doyle wrote: >> On Wed, 4 Feb 2015, Nicholas Mc Guire wrote: >>> The if and the else branch code are identical - so the condition has no >>> effect on the effective code - this patch removes the condition and the >>> duplicated code. >>> >>> Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> >>> --- >>> >>> This code has been in here since commit 544393fe584d ("sisfb update") so I guess it is >>> safe to simply remove the duplicated code if nobody noticed for 10 years. >>> >>> Note that the code is not really CodingStyle compliant - the lines inserted were formatted >>> to satisfy the coding style but I'm unsure if it is not better to leave it in the >>> old format. >>> >>> Patch was only compile tested with x86_64_defconfig + >>> CONFIG_FB_SIS=m, CONFIG_FB_SIS_300=y, CONFIG_FB_SIS_315=y >>> >>> Patch is against 3.19.0-rc7 (localversion-next is -next-20150204) >>> >>> drivers/video/fbdev/sis/init301.c | 9 ++------- >>> 1 file changed, 2 insertions(+), 7 deletions(-) >>> >>> diff --git a/drivers/video/fbdev/sis/init301.c b/drivers/video/fbdev/sis/init301.c >>> index 295e0de..9533a8ab 100644 >>> --- a/drivers/video/fbdev/sis/init301.c >>> +++ b/drivers/video/fbdev/sis/init301.c >>> @@ -7971,13 +7971,8 @@ SiS_SetCHTVReg(struct SiS_Private *SiS_Pr, unsigned short ModeNo, unsigned short >>> } >>> } else { /* ---- PAL ---- */ >>> /* We don't play around with FSCI in PAL mode */ >>> - if(resindex == 0x04) { >>> - SiS_SetCH70xxANDOR(SiS_Pr,0x20,0x00,0xEF); /* loop filter off */ >>> - SiS_SetCH70xxANDOR(SiS_Pr,0x21,0x01,0xFE); /* ACIV on */ >>> - } else { >>> - SiS_SetCH70xxANDOR(SiS_Pr,0x20,0x00,0xEF); /* loop filter off */ >>> - SiS_SetCH70xxANDOR(SiS_Pr,0x21,0x01,0xFE); /* ACIV on */ >>> - } >>> + SiS_SetCH70xxANDOR(SiS_Pr, 0x20, 0x00, 0xEF); /* loop filter off */ >>> + SiS_SetCH70xxANDOR(SiS_Pr, 0x21, 0x01, 0xFE); /* ACIV on */ >>> } >>> >>> #endif /* 300 */ >> The code covering the PAL case had this redundancy when it was introduced >> in Linux 2.4.19. >> >> Lines 7934-7981 consider three variables: PAL, overscan, and resindex. >> Given the "#ifdef 0" block, couldn't the current six sections collapse >> into two? One for (!PAL && overscan && resindex==5) and another for the >> rest? > > Are we sure there isn't a typo in one of the duplicate clauses? Or > wrong copy-pasting? Generally I am skeptical to "fixing" code without > understanding what is behind or testing it, and just cosmetically > brush over it. For now at least it is obvious that there is something > wrong. In case (although an unlikely one) someone who understands the > code and knows this chip comes along, he would quickly spot this. > After your "fixups" this will be all forgotten. Additionally it adds > to the impression that this code is being maintained, which is wrong. > > I would understand an argument about annoying compiler warnings and > the like, but in that case I would prefer to #if 0 it instead of > "prettifying" it. > > 0.02 > Tormod > The code is partly unfinished due to a lack of hardware to test this with. SiS announced SiS+Chrontel 7019 combos at some point but I have never seen one. The code was written based on the Chrontel datasheets, which weren't clear to some extent, and there wasn't ever any test hardware. I don't recall this one exactly, but identical if-else statements mean that one alternative is (assumingly) correct, while the other is uncertain and/or untested. I left such redunant if-statements in the code to remember the conditions and the fact that there is a second alternative. Considering the long time I'd say it's safe to simplify this. A word on other changes I monitored recently: Please bear in mind that with video hardware reading and writing registers is not simple like reading and writing to memory. Sometimes reading causes an effect in the hardware as well (latches, etc), so removing seemingly redundant GetReg/SetReg sequences might actually have an effect. Regards Thomas - -- Thomas Winischhofer thomas AT winischhofer DOT net -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (Darwin) iD8DBQFU1GaUzydIRAktyUcRAuQlAJ9NL3moUDf0yUMbE9qi4L26hT69NwCcDOk2 GyZjN8fic9bITTtdK9OG0R8= =s9pA -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 05 Feb 2015, Tormod Volden wrote: > On Thu, Feb 5, 2015 at 9:45 PM, Scot Doyle wrote: > > On Wed, 4 Feb 2015, Nicholas Mc Guire wrote: > >> The if and the else branch code are identical - so the condition has no > >> effect on the effective code - this patch removes the condition and the > >> duplicated code. > >> > >> Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> > >> --- > >> > >> This code has been in here since commit 544393fe584d ("sisfb update") so I guess it is > >> safe to simply remove the duplicated code if nobody noticed for 10 years. > >> > >> Note that the code is not really CodingStyle compliant - the lines inserted were formatted > >> to satisfy the coding style but I'm unsure if it is not better to leave it in the > >> old format. > >> > >> Patch was only compile tested with x86_64_defconfig + > >> CONFIG_FB_SIS=m, CONFIG_FB_SIS_300=y, CONFIG_FB_SIS_315=y > >> > >> Patch is against 3.19.0-rc7 (localversion-next is -next-20150204) > >> > >> drivers/video/fbdev/sis/init301.c | 9 ++------- > >> 1 file changed, 2 insertions(+), 7 deletions(-) > >> > >> diff --git a/drivers/video/fbdev/sis/init301.c b/drivers/video/fbdev/sis/init301.c > >> index 295e0de..9533a8ab 100644 > >> --- a/drivers/video/fbdev/sis/init301.c > >> +++ b/drivers/video/fbdev/sis/init301.c > >> @@ -7971,13 +7971,8 @@ SiS_SetCHTVReg(struct SiS_Private *SiS_Pr, unsigned short ModeNo, unsigned short > >> } > >> } else { /* ---- PAL ---- */ > >> /* We don't play around with FSCI in PAL mode */ > >> - if(resindex == 0x04) { > >> - SiS_SetCH70xxANDOR(SiS_Pr,0x20,0x00,0xEF); /* loop filter off */ > >> - SiS_SetCH70xxANDOR(SiS_Pr,0x21,0x01,0xFE); /* ACIV on */ > >> - } else { > >> - SiS_SetCH70xxANDOR(SiS_Pr,0x20,0x00,0xEF); /* loop filter off */ > >> - SiS_SetCH70xxANDOR(SiS_Pr,0x21,0x01,0xFE); /* ACIV on */ > >> - } > >> + SiS_SetCH70xxANDOR(SiS_Pr, 0x20, 0x00, 0xEF); /* loop filter off */ > >> + SiS_SetCH70xxANDOR(SiS_Pr, 0x21, 0x01, 0xFE); /* ACIV on */ > >> } > >> > >> #endif /* 300 */ > > > > The code covering the PAL case had this redundancy when it was introduced > > in Linux 2.4.19. > > > > Lines 7934-7981 consider three variables: PAL, overscan, and resindex. > > Given the "#ifdef 0" block, couldn't the current six sections collapse > > into two? One for (!PAL && overscan && resindex==5) and another for the > > rest? > > Are we sure there isn't a typo in one of the duplicate clauses? Or > wrong copy-pasting? Generally I am skeptical to "fixing" code without > understanding what is behind or testing it, and just cosmetically > brush over it. For now at least it is obvious that there is something > wrong. In case (although an unlikely one) someone who understands the > code and knows this chip comes along, he would quickly spot this. > After your "fixups" this will be all forgotten. Additionally it adds > to the impression that this code is being maintained, which is wrong. > > I would understand an argument about annoying compiler warnings and > the like, but in that case I would prefer to #if 0 it instead of > "prettifying" it. > Its actually a static code checker that is fussing at this. The #if 0 case is on my list as well - but thats a different scanner - and thus goes into a separate patch. I agree that it could be a hidden bug - but given that its this way for 10 years I doubt this. thx! hofrat -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, 06 Feb 2015, Thomas Winischhofer wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Tormod Volden wrote: > > On Thu, Feb 5, 2015 at 9:45 PM, Scot Doyle wrote: > >> On Wed, 4 Feb 2015, Nicholas Mc Guire wrote: > >>> The if and the else branch code are identical - so the condition has no > >>> effect on the effective code - this patch removes the condition and the > >>> duplicated code. > >>> > >>> Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> > >>> --- > >>> > >>> This code has been in here since commit 544393fe584d ("sisfb update") so I guess it is > >>> safe to simply remove the duplicated code if nobody noticed for 10 years. > >>> > >>> Note that the code is not really CodingStyle compliant - the lines inserted were formatted > >>> to satisfy the coding style but I'm unsure if it is not better to leave it in the > >>> old format. > >>> > >>> Patch was only compile tested with x86_64_defconfig + > >>> CONFIG_FB_SIS=m, CONFIG_FB_SIS_300=y, CONFIG_FB_SIS_315=y > >>> > >>> Patch is against 3.19.0-rc7 (localversion-next is -next-20150204) > >>> > >>> drivers/video/fbdev/sis/init301.c | 9 ++------- > >>> 1 file changed, 2 insertions(+), 7 deletions(-) > >>> > >>> diff --git a/drivers/video/fbdev/sis/init301.c b/drivers/video/fbdev/sis/init301.c > >>> index 295e0de..9533a8ab 100644 > >>> --- a/drivers/video/fbdev/sis/init301.c > >>> +++ b/drivers/video/fbdev/sis/init301.c > >>> @@ -7971,13 +7971,8 @@ SiS_SetCHTVReg(struct SiS_Private *SiS_Pr, unsigned short ModeNo, unsigned short > >>> } > >>> } else { /* ---- PAL ---- */ > >>> /* We don't play around with FSCI in PAL mode */ > >>> - if(resindex == 0x04) { > >>> - SiS_SetCH70xxANDOR(SiS_Pr,0x20,0x00,0xEF); /* loop filter off */ > >>> - SiS_SetCH70xxANDOR(SiS_Pr,0x21,0x01,0xFE); /* ACIV on */ > >>> - } else { > >>> - SiS_SetCH70xxANDOR(SiS_Pr,0x20,0x00,0xEF); /* loop filter off */ > >>> - SiS_SetCH70xxANDOR(SiS_Pr,0x21,0x01,0xFE); /* ACIV on */ > >>> - } > >>> + SiS_SetCH70xxANDOR(SiS_Pr, 0x20, 0x00, 0xEF); /* loop filter off */ > >>> + SiS_SetCH70xxANDOR(SiS_Pr, 0x21, 0x01, 0xFE); /* ACIV on */ > >>> } > >>> > >>> #endif /* 300 */ > >> The code covering the PAL case had this redundancy when it was introduced > >> in Linux 2.4.19. > >> > >> Lines 7934-7981 consider three variables: PAL, overscan, and resindex. > >> Given the "#ifdef 0" block, couldn't the current six sections collapse > >> into two? One for (!PAL && overscan && resindex==5) and another for the > >> rest? > > > > Are we sure there isn't a typo in one of the duplicate clauses? Or > > wrong copy-pasting? Generally I am skeptical to "fixing" code without > > understanding what is behind or testing it, and just cosmetically > > brush over it. For now at least it is obvious that there is something > > wrong. In case (although an unlikely one) someone who understands the > > code and knows this chip comes along, he would quickly spot this. > > After your "fixups" this will be all forgotten. Additionally it adds > > to the impression that this code is being maintained, which is wrong. > > > > I would understand an argument about annoying compiler warnings and > > the like, but in that case I would prefer to #if 0 it instead of > > "prettifying" it. > > > > 0.02 > > Tormod > > > > The code is partly unfinished due to a lack of hardware to test this > with. SiS announced SiS+Chrontel 7019 combos at some point but I have > never seen one. The code was written based on the Chrontel datasheets, > which weren't clear to some extent, and there wasn't ever any test > hardware. I don't recall this one exactly, but identical if-else > statements mean that one alternative is (assumingly) correct, while the > other is uncertain and/or untested. I left such redunant if-statements > in the code to remember the conditions and the fact that there is a > second alternative. > > Considering the long time I'd say it's safe to simplify this. > > A word on other changes I monitored recently: Please bear in mind that > with video hardware reading and writing registers is not simple like > reading and writing to memory. Sometimes reading causes an effect in the > hardware as well (latches, etc), so removing seemingly redundant > GetReg/SetReg sequences might actually have an effect. > thanks for that note - will add that to my checklist of sideffects for future patches. thx! hofrat -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Nicholas Mc Guire wrote: > On Fri, 06 Feb 2015, Thomas Winischhofer wrote: > >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA1 >> >> Tormod Volden wrote: >>> On Thu, Feb 5, 2015 at 9:45 PM, Scot Doyle wrote: >>>> On Wed, 4 Feb 2015, Nicholas Mc Guire wrote: >>>>> The if and the else branch code are identical - so the condition has no >>>>> effect on the effective code - this patch removes the condition and the >>>>> duplicated code. >>>>> >>>>> Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> >>>>> --- >>>>> >>>>> This code has been in here since commit 544393fe584d ("sisfb update") so I guess it is >>>>> safe to simply remove the duplicated code if nobody noticed for 10 years. >>>>> >>>>> Note that the code is not really CodingStyle compliant - the lines inserted were formatted >>>>> to satisfy the coding style but I'm unsure if it is not better to leave it in the >>>>> old format. >>>>> >>>>> Patch was only compile tested with x86_64_defconfig + >>>>> CONFIG_FB_SIS=m, CONFIG_FB_SIS_300=y, CONFIG_FB_SIS_315=y >>>>> >>>>> Patch is against 3.19.0-rc7 (localversion-next is -next-20150204) >>>>> >>>>> drivers/video/fbdev/sis/init301.c | 9 ++------- >>>>> 1 file changed, 2 insertions(+), 7 deletions(-) >>>>> >>>>> diff --git a/drivers/video/fbdev/sis/init301.c b/drivers/video/fbdev/sis/init301.c >>>>> index 295e0de..9533a8ab 100644 >>>>> --- a/drivers/video/fbdev/sis/init301.c >>>>> +++ b/drivers/video/fbdev/sis/init301.c >>>>> @@ -7971,13 +7971,8 @@ SiS_SetCHTVReg(struct SiS_Private *SiS_Pr, unsigned short ModeNo, unsigned short >>>>> } >>>>> } else { /* ---- PAL ---- */ >>>>> /* We don't play around with FSCI in PAL mode */ >>>>> - if(resindex == 0x04) { >>>>> - SiS_SetCH70xxANDOR(SiS_Pr,0x20,0x00,0xEF); /* loop filter off */ >>>>> - SiS_SetCH70xxANDOR(SiS_Pr,0x21,0x01,0xFE); /* ACIV on */ >>>>> - } else { >>>>> - SiS_SetCH70xxANDOR(SiS_Pr,0x20,0x00,0xEF); /* loop filter off */ >>>>> - SiS_SetCH70xxANDOR(SiS_Pr,0x21,0x01,0xFE); /* ACIV on */ >>>>> - } >>>>> + SiS_SetCH70xxANDOR(SiS_Pr, 0x20, 0x00, 0xEF); /* loop filter off */ >>>>> + SiS_SetCH70xxANDOR(SiS_Pr, 0x21, 0x01, 0xFE); /* ACIV on */ >>>>> } >>>>> >>>>> #endif /* 300 */ >>>> The code covering the PAL case had this redundancy when it was introduced >>>> in Linux 2.4.19. >>>> >>>> Lines 7934-7981 consider three variables: PAL, overscan, and resindex. >>>> Given the "#ifdef 0" block, couldn't the current six sections collapse >>>> into two? One for (!PAL && overscan && resindex==5) and another for the >>>> rest? >>> Are we sure there isn't a typo in one of the duplicate clauses? Or >>> wrong copy-pasting? Generally I am skeptical to "fixing" code without >>> understanding what is behind or testing it, and just cosmetically >>> brush over it. For now at least it is obvious that there is something >>> wrong. In case (although an unlikely one) someone who understands the >>> code and knows this chip comes along, he would quickly spot this. >>> After your "fixups" this will be all forgotten. Additionally it adds >>> to the impression that this code is being maintained, which is wrong. >>> >>> I would understand an argument about annoying compiler warnings and >>> the like, but in that case I would prefer to #if 0 it instead of >>> "prettifying" it. >>> >>> 0.02 >>> Tormod >>> >> The code is partly unfinished due to a lack of hardware to test this >> with. SiS announced SiS+Chrontel 7019 combos at some point but I have >> never seen one. The code was written based on the Chrontel datasheets, >> which weren't clear to some extent, and there wasn't ever any test >> hardware. I don't recall this one exactly, but identical if-else >> statements mean that one alternative is (assumingly) correct, while the >> other is uncertain and/or untested. I left such redunant if-statements >> in the code to remember the conditions and the fact that there is a >> second alternative. >> >> Considering the long time I'd say it's safe to simplify this. >> >> A word on other changes I monitored recently: Please bear in mind that >> with video hardware reading and writing registers is not simple like >> reading and writing to memory. Sometimes reading causes an effect in the >> hardware as well (latches, etc), so removing seemingly redundant >> GetReg/SetReg sequences might actually have an effect. >> > thanks for that note - will add that to my checklist of sideffects > for future patches. > > thx! > hofrat > PS: Correction: This code is for the SiS+Chrontel 7005 (not 7019) case, and there actually WAS hardware. Therefore I also probably tested this, or this is the remains of a test, and as a consequence it is safe to simplify/remove. - -- Thomas Winischhofer thomas AT winischhofer DOT net -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (Darwin) iD8DBQFU1NCFzydIRAktyUcRAkN4AJ9CqUVCbEKyUkSOPvCkRWzKDeaPPQCfdQ4e ffzCiVCH5Ul7kAXiL/K0RDU= =tt8c -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" 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/video/fbdev/sis/init301.c b/drivers/video/fbdev/sis/init301.c index 295e0de..9533a8ab 100644 --- a/drivers/video/fbdev/sis/init301.c +++ b/drivers/video/fbdev/sis/init301.c @@ -7971,13 +7971,8 @@ SiS_SetCHTVReg(struct SiS_Private *SiS_Pr, unsigned short ModeNo, unsigned short } } else { /* ---- PAL ---- */ /* We don't play around with FSCI in PAL mode */ - if(resindex == 0x04) { - SiS_SetCH70xxANDOR(SiS_Pr,0x20,0x00,0xEF); /* loop filter off */ - SiS_SetCH70xxANDOR(SiS_Pr,0x21,0x01,0xFE); /* ACIV on */ - } else { - SiS_SetCH70xxANDOR(SiS_Pr,0x20,0x00,0xEF); /* loop filter off */ - SiS_SetCH70xxANDOR(SiS_Pr,0x21,0x01,0xFE); /* ACIV on */ - } + SiS_SetCH70xxANDOR(SiS_Pr, 0x20, 0x00, 0xEF); /* loop filter off */ + SiS_SetCH70xxANDOR(SiS_Pr, 0x21, 0x01, 0xFE); /* ACIV on */ } #endif /* 300 */
The if and the else branch code are identical - so the condition has no effect on the effective code - this patch removes the condition and the duplicated code. Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> --- This code has been in here since commit 544393fe584d ("sisfb update") so I guess it is safe to simply remove the duplicated code if nobody noticed for 10 years. Note that the code is not really CodingStyle compliant - the lines inserted were formatted to satisfy the coding style but I'm unsure if it is not better to leave it in the old format. Patch was only compile tested with x86_64_defconfig + CONFIG_FB_SIS=m, CONFIG_FB_SIS_300=y, CONFIG_FB_SIS_315=y Patch is against 3.19.0-rc7 (localversion-next is -next-20150204) drivers/video/fbdev/sis/init301.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-)