From 85451a951b9511605475fadcc0a8d3aeccefded8 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Fri, 20 Mar 2009 13:27:13 +0000 Subject: [PATCH] sfc: Optimise falcon_writel_page_locked() for page > 0 The bug this function works around only applies to the first set of page-mapped registers; other pages can be written without locking. Signed-off-by: Ben Hutchings Signed-off-by: David S. Miller --- drivers/net/sfc/falcon_io.h | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/net/sfc/falcon_io.h b/drivers/net/sfc/falcon_io.h index c16da3149fa9..8883092dae97 100644 --- a/drivers/net/sfc/falcon_io.h +++ b/drivers/net/sfc/falcon_io.h @@ -238,18 +238,21 @@ static inline void falcon_writel_page(struct efx_nic *efx, efx_dword_t *value, /* Write dword to Falcon page-mapped register with an extra lock. * * As for falcon_writel_page(), but for a register that suffers from - * SFC bug 3181. Take out a lock so the BIU collector cannot be - * confused. */ + * SFC bug 3181. If writing to page 0, take out a lock so the BIU + * collector cannot be confused. + */ static inline void falcon_writel_page_locked(struct efx_nic *efx, efx_dword_t *value, unsigned int reg, unsigned int page) { - unsigned long flags; + unsigned long flags = 0; - spin_lock_irqsave(&efx->biu_lock, flags); + if (page == 0) + spin_lock_irqsave(&efx->biu_lock, flags); falcon_writel(efx, value, FALCON_PAGED_REG(page, reg)); - spin_unlock_irqrestore(&efx->biu_lock, flags); + if (page == 0) + spin_unlock_irqrestore(&efx->biu_lock, flags); } #endif /* EFX_FALCON_IO_H */