| Message ID | 1443223157-10039-1-git-send-email-mrochs@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
On 26/09/15 09:19, Matthew R. Ochs wrote: > From: Manoj Kumar <manoj@linux.vnet.ibm.com> > > The operator used to double the delay is incorrect and > does not result in delay doubling. > > To fix, use a left shift instead of the XOR operator. > > Reported-by: Tomas Henzl <thenzl@redhat.com> > Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> > Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> > Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 "Matthew R. Ochs" <mrochs@linux.vnet.ibm.com> writes: > From: Manoj Kumar <manoj@linux.vnet.ibm.com> > > The operator used to double the delay is incorrect and > does not result in delay doubling. > > To fix, use a left shift instead of the XOR operator. > I can see that the patch is correct, but this commit message is a bit confusing. What delay? In what circumstances are you doubling it? Why? Regards, Daniel > Reported-by: Tomas Henzl <thenzl@redhat.com> > Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> > Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> > Reviewed-by: Brian King <brking@linux.vnet.ibm.com> > --- > drivers/scsi/cxlflash/main.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c > index ab11ee6..be78906 100644 > --- a/drivers/scsi/cxlflash/main.c > +++ b/drivers/scsi/cxlflash/main.c > @@ -303,7 +303,7 @@ write_rrin: > if (rrin != 0x1) > break; > /* Double delay each time */ > - udelay(2 ^ nretry); > + udelay(2 << nretry); > } while (nretry++ < MC_ROOM_RETRY_CNT); > } > > -- > 2.1.0 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: GPGTools - https://gpgtools.org iQIcBAEBCgAGBQJWCewRAAoJEPC3R3P2I92F7xQQAKxvcnUpB/xLeq6CyB3LwsB/ cqFMP7OwDRfmQZG5ld5uqfXsjCCW4c0BaVknMgpD5gAdHbrwbc5gFgYuC0kIDUrH aEwTyXwaH7+o82agjxf7TRrsh2NtLzdSB6NN1UNL73aPVXJFKWITajIKUAnYF5d1 AvB3yb4KtX0qklo205igVceuLbBBaXY6Lz3V58XDSG2JAtVlVkamJK7M8zySrNTY Y627zTVkbopOGaBMLmu0q92dWDk2saU2wqKolo+pRy1NpOmY2XOU9hSRqCqAhnS4 xOWj7Bdrh1HdnQX26EC+f485nOijf0zddpJ6LsgPWMElJ04N4siQwmrwG55FbOs4 QDFKPdsVdZ8qmVueGCLRdTsMNAxcobi44P1/QXxGTmsn9xqyQBgZUzbd5oRUVswI md21qir3xjRN7g4R78084I88dM1yrHpJ6NuHDxFeXbtrw8087lKgU05Ys6m+ebuC 7nPnYRJ54frAi6a7mmBq+Xc4IbVnaGl9IZi1gujM2mkTaAk7/wl7oRMYyUTKlblp BeoQN0cdG1fChP1yLHzZV6G1JXwSw7nP6otf7YfUIrmjbzeZ5zWovSqJjnvNYBCT zgW681gIF3GwaN9z9I+XY9BO1P6EkYp+dgAQM7PqdR00GjFjTJO0yn8WHh113lmE L2sC0Nezuq8V4/qtspmh =Km/z -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> On Sep 28, 2015, at 8:40 PM, Daniel Axtens <dja@axtens.net> wrote: > > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA512 > > "Matthew R. Ochs" <mrochs@linux.vnet.ibm.com> writes: > >> From: Manoj Kumar <manoj@linux.vnet.ibm.com> >> >> The operator used to double the delay is incorrect and >> does not result in delay doubling. >> >> To fix, use a left shift instead of the XOR operator. >> > I can see that the patch is correct, but this commit message is a bit > confusing. What delay? In what circumstances are you doubling it? Why? This is the response delay while resetting the master context. The reset is performed by writing a bit and then waiting for it to clear. While waiting for it to clear, the code relaxes the delta between MMIO reads. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
"Matthew R. Ochs" <mrochs@linux.vnet.ibm.com> writes: >> On Sep 28, 2015, at 8:40 PM, Daniel Axtens <dja@axtens.net> wrote: >> >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA512 >> >> "Matthew R. Ochs" <mrochs@linux.vnet.ibm.com> writes: >> >>> From: Manoj Kumar <manoj@linux.vnet.ibm.com> >>> >>> The operator used to double the delay is incorrect and >>> does not result in delay doubling. >>> >>> To fix, use a left shift instead of the XOR operator. >>> >> I can see that the patch is correct, but this commit message is a bit >> confusing. What delay? In what circumstances are you doubling it? Why? > > This is the response delay while resetting the master context. The reset > is performed by writing a bit and then waiting for it to clear. While waiting > for it to clear, the code relaxes the delta between MMIO reads. OK. If you do a v5, please include this in the commit message. Regards, Daniel -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" 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/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c index ab11ee6..be78906 100644 --- a/drivers/scsi/cxlflash/main.c +++ b/drivers/scsi/cxlflash/main.c @@ -303,7 +303,7 @@ write_rrin: if (rrin != 0x1) break; /* Double delay each time */ - udelay(2 ^ nretry); + udelay(2 << nretry); } while (nretry++ < MC_ROOM_RETRY_CNT); }