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 <bhutchings@solarflare.com>
---
drivers/net/sfc/falcon_io.h | 13 ++++++++-----
1 files changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/net/sfc/falcon_io.h b/drivers/net/sfc/falcon_io.h
index c16da31..8883092 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 */
--
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.
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