| Message ID | 1471020992-22402-1-git-send-email-david.m.ertman@intel.com |
|---|---|
| State | Accepted |
| Delegated to: | Jeff Kirsher |
| Headers | show |
> -----Original Message----- > From: Intel-wired-lan [mailto:intel-wired-lan-bounces@lists.osuosl.org] On > Behalf Of Dave Ertman > Sent: Friday, August 12, 2016 9:57 AM > To: intel-wired-lan@lists.osuosl.org > Subject: [Intel-wired-lan] [PATCH] i40e: check for and deal with non- > contiguous TCs > > The i40e driver was causing a kernel panic when non-contiguous Traffic > Classes, or Traffic Classes not starting with TC0, were configured on a link > partner switch. > i40e does not support non-contiguous TCs. > > To fix this, the patch changes the logic when determining the total number of > TCs enabled. Before, this would use the highest TC number enabled and > assume that all TCs below it were also enabled. Now, we create a bitmask of > enabled TCs and scan it to determine not only the number of TCs, but also if > the set of enabled TCs starts at zero and is contiguous. If not, then DCB is > disabled by only returning one TC. > > Signed-off-by: Dave Ertman <david.m.ertman@intel.com> > --- > drivers/net/ethernet/intel/i40e/i40e_main.c | 35 > ++++++++++++++++++++--------- > 1 file changed, 25 insertions(+), 10 deletions(-) Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c index 81c99e1..c6ac7a6 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -4554,23 +4554,38 @@ static u8 i40e_get_iscsi_tc_map(struct i40e_pf *pf) **/ static u8 i40e_dcb_get_num_tc(struct i40e_dcbx_config *dcbcfg) { + int i, tc_unused = 0; u8 num_tc = 0; - int i; + u8 ret = 0; /* Scan the ETS Config Priority Table to find * traffic class enabled for a given priority - * and use the traffic class index to get the - * number of traffic classes enabled + * and create a bitmask of enabled TCs */ - for (i = 0; i < I40E_MAX_USER_PRIORITY; i++) { - if (dcbcfg->etscfg.prioritytable[i] > num_tc) - num_tc = dcbcfg->etscfg.prioritytable[i]; - } + for (i = 0; i < I40E_MAX_USER_PRIORITY; i++) + num_tc |= BIT(dcbcfg->etscfg.prioritytable[i]); - /* Traffic class index starts from zero so - * increment to return the actual count + /* Now scan the bitmask to check for + * contiguous TCs starting with TC0 */ - return num_tc + 1; + for (i = 0; i < I40E_MAX_TRAFFIC_CLASS; i++) { + if (num_tc & BIT(i)) { + if (!tc_unused) { + ret++; + } else { + pr_err("Non-contiguous TC - Disabling DCB\n"); + return 1; + } + } else { + tc_unused = 1; + } + } + + /* There is always at least TC0 */ + if (!ret) + ret = 1; + + return ret; } /**
The i40e driver was causing a kernel panic when non-contiguous Traffic Classes, or Traffic Classes not starting with TC0, were configured on a link partner switch. i40e does not support non-contiguous TCs. To fix this, the patch changes the logic when determining the total number of TCs enabled. Before, this would use the highest TC number enabled and assume that all TCs below it were also enabled. Now, we create a bitmask of enabled TCs and scan it to determine not only the number of TCs, but also if the set of enabled TCs starts at zero and is contiguous. If not, then DCB is disabled by only returning one TC. Signed-off-by: Dave Ertman <david.m.ertman@intel.com> --- drivers/net/ethernet/intel/i40e/i40e_main.c | 35 ++++++++++++++++++++--------- 1 file changed, 25 insertions(+), 10 deletions(-)