diff options
| author | Ben Hutchings <bhutchings@solarflare.com> | 2011-12-08 19:51:47 (GMT) |
|---|---|---|
| committer | Ben Hutchings <bhutchings@solarflare.com> | 2012-01-27 00:10:50 (GMT) |
| commit | cc180b69c009ec52f67a56d96b9073b9f774b323 (patch) | |
| tree | 2d20225099a9a08d3471aeb3cd8ce4295417e5e6 /drivers/net/ethernet/sfc/efx.c | |
| parent | 6aa9c7f625e8ce07060467051b68fc068118ee64 (diff) | |
| download | linux-fsl-qoriq-cc180b69c009ec52f67a56d96b9073b9f774b323.tar.xz | |
sfc: Correct interrupt timer quantum for Siena (normal and turbo mode)
We currently assume that the timer quantum for Siena is 5 us, the same
as for Falcon. This is not correct; timer ticks are generated on a
rota which takes a minimum of 768 cycles (each event delivery or other
timer change will delay it by 3 cycles). The timer quantum should be
6.144 or 3.072 us depending on whether turbo mode is active.
Replace EFX_IRQ_MOD_RESOLUTION with a timer_quantum_ns field in struct
efx_nic, initialised by the efx_nic_type::probe function.
While we're at it, replace EFX_IRQ_MOD_MAX with a timer_period_max
field in struct efx_nic_type.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Diffstat (limited to 'drivers/net/ethernet/sfc/efx.c')
| -rw-r--r-- | drivers/net/ethernet/sfc/efx.c | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c index de16247..9d4ab5e 100644 --- a/drivers/net/ethernet/sfc/efx.c +++ b/drivers/net/ethernet/sfc/efx.c @@ -1513,13 +1513,13 @@ static void efx_remove_all(struct efx_nic *efx) * **************************************************************************/ -static unsigned int irq_mod_ticks(unsigned int usecs, unsigned int resolution) +static unsigned int irq_mod_ticks(unsigned int usecs, unsigned int quantum_ns) { if (usecs == 0) return 0; - if (usecs < resolution) + if (usecs * 1000 < quantum_ns) return 1; /* never round down to 0 */ - return usecs / resolution; + return usecs * 1000 / quantum_ns; } /* Set interrupt moderation parameters */ @@ -1528,14 +1528,20 @@ int efx_init_irq_moderation(struct efx_nic *efx, unsigned int tx_usecs, bool rx_may_override_tx) { struct efx_channel *channel; - unsigned tx_ticks = irq_mod_ticks(tx_usecs, EFX_IRQ_MOD_RESOLUTION); - unsigned rx_ticks = irq_mod_ticks(rx_usecs, EFX_IRQ_MOD_RESOLUTION); + unsigned int irq_mod_max = DIV_ROUND_UP(efx->type->timer_period_max * + efx->timer_quantum_ns, + 1000); + unsigned int tx_ticks; + unsigned int rx_ticks; EFX_ASSERT_RESET_SERIALISED(efx); - if (tx_ticks > EFX_IRQ_MOD_MAX || rx_ticks > EFX_IRQ_MOD_MAX) + if (tx_usecs > irq_mod_max || rx_usecs > irq_mod_max) return -EINVAL; + tx_ticks = irq_mod_ticks(tx_usecs, efx->timer_quantum_ns); + rx_ticks = irq_mod_ticks(rx_usecs, efx->timer_quantum_ns); + if (tx_ticks != rx_ticks && efx->tx_channel_offset == 0 && !rx_may_override_tx) { netif_err(efx, drv, efx->net_dev, "Channels are shared. " @@ -1558,8 +1564,14 @@ int efx_init_irq_moderation(struct efx_nic *efx, unsigned int tx_usecs, void efx_get_irq_moderation(struct efx_nic *efx, unsigned int *tx_usecs, unsigned int *rx_usecs, bool *rx_adaptive) { + /* We must round up when converting ticks to microseconds + * because we round down when converting the other way. + */ + *rx_adaptive = efx->irq_rx_adaptive; - *rx_usecs = efx->irq_rx_moderation * EFX_IRQ_MOD_RESOLUTION; + *rx_usecs = DIV_ROUND_UP(efx->irq_rx_moderation * + efx->timer_quantum_ns, + 1000); /* If channels are shared between RX and TX, so is IRQ * moderation. Otherwise, IRQ moderation is the same for all @@ -1568,9 +1580,10 @@ void efx_get_irq_moderation(struct efx_nic *efx, unsigned int *tx_usecs, if (efx->tx_channel_offset == 0) *tx_usecs = *rx_usecs; else - *tx_usecs = + *tx_usecs = DIV_ROUND_UP( efx->channel[efx->tx_channel_offset]->irq_moderation * - EFX_IRQ_MOD_RESOLUTION; + efx->timer_quantum_ns, + 1000); } /************************************************************************** |