diff options
| author | Mika Westerberg <mika.westerberg@linux.intel.com> | 2017-10-02 13:38:35 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-10-02 21:24:41 +0300 |
| commit | 8c6bba10fb9262d7b3a11e86a40621d5b37810a6 (patch) | |
| tree | dd1ea0a7e55932118808c6721a6da67adf044aa3 | |
| parent | d1ff70241a275133e1a0258b7c23588b122276c8 (diff) | |
| download | linux-8c6bba10fb9262d7b3a11e86a40621d5b37810a6.tar.xz | |
thunderbolt: Configure interrupt throttling for all interrupts
This will keep the interrupt delivery rate reasonable. The value used
here (128 us) is a recommendation from the hardware people.
This code is based on the work done by Amir Levy and Michael Jamet.
Signed-off-by: Michael Jamet <michael.jamet@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/thunderbolt/nhi.c | 23 | ||||
| -rw-r--r-- | drivers/thunderbolt/nhi_regs.h | 2 |
2 files changed, 22 insertions, 3 deletions
diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c index 05af126a2435..8a7a3d0133f9 100644 --- a/drivers/thunderbolt/nhi.c +++ b/drivers/thunderbolt/nhi.c @@ -651,6 +651,22 @@ static int nhi_suspend_noirq(struct device *dev) return tb_domain_suspend_noirq(tb); } +static void nhi_enable_int_throttling(struct tb_nhi *nhi) +{ + /* Throttling is specified in 256ns increments */ + u32 throttle = DIV_ROUND_UP(128 * NSEC_PER_USEC, 256); + unsigned int i; + + /* + * Configure interrupt throttling for all vectors even if we + * only use few. + */ + for (i = 0; i < MSIX_MAX_VECS; i++) { + u32 reg = REG_INT_THROTTLING_RATE + i * 4; + iowrite32(throttle, nhi->iobase + reg); + } +} + static int nhi_resume_noirq(struct device *dev) { struct pci_dev *pdev = to_pci_dev(dev); @@ -663,6 +679,8 @@ static int nhi_resume_noirq(struct device *dev) */ if (!pci_device_is_present(pdev)) tb->nhi->going_away = true; + else + nhi_enable_int_throttling(tb->nhi); return tb_domain_resume_noirq(tb); } @@ -717,6 +735,8 @@ static int nhi_init_msi(struct tb_nhi *nhi) /* In case someone left them on. */ nhi_disable_interrupts(nhi); + nhi_enable_int_throttling(nhi); + ida_init(&nhi->msix_ida); /* @@ -796,9 +816,6 @@ static int nhi_probe(struct pci_dev *pdev, const struct pci_device_id *id) pci_set_master(pdev); - /* magic value - clock related? */ - iowrite32(3906250 / 10000, nhi->iobase + 0x38c00); - tb = icm_probe(nhi); if (!tb) tb = tb_probe(nhi); diff --git a/drivers/thunderbolt/nhi_regs.h b/drivers/thunderbolt/nhi_regs.h index 09ed574e92ff..46eff69b19ad 100644 --- a/drivers/thunderbolt/nhi_regs.h +++ b/drivers/thunderbolt/nhi_regs.h @@ -95,6 +95,8 @@ struct ring_desc { #define REG_RING_INTERRUPT_BASE 0x38200 #define RING_INTERRUPT_REG_COUNT(nhi) ((31 + 2 * nhi->hop_count) / 32) +#define REG_INT_THROTTLING_RATE 0x38c00 + /* Interrupt Vector Allocation */ #define REG_INT_VEC_ALLOC_BASE 0x38c40 #define REG_INT_VEC_ALLOC_BITS 4 |