Messages in this thread Patch in this message | | | From | Liu Xiang <> | Subject | [PATCH] net: davicom: dm9000: Avoid spinlock recursion during dm9000_timeout routine | Date | Wed, 31 May 2017 23:06:42 +0800 |
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On the DM9000B, dm9000_phy_write() is called after the main spinlock is held, during the dm9000_timeout() routine. Spinlock recursion occurs because the main spinlock is requested again in dm9000_phy_write(). So spinlock should be avoided in dm9000_phy_write() during the dm9000_timeout() routine.
Signed-off-by: Liu Xiang <liu.xiang6@zte.com.cn> --- drivers/net/ethernet/davicom/dm9000.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-)
diff --git a/drivers/net/ethernet/davicom/dm9000.c b/drivers/net/ethernet/davicom/dm9000.c index 008dc81..afe33de 100644 --- a/drivers/net/ethernet/davicom/dm9000.c +++ b/drivers/net/ethernet/davicom/dm9000.c @@ -337,11 +337,11 @@ static void dm9000_msleep(struct board_info *db, unsigned int ms) unsigned long reg_save; dm9000_dbg(db, 5, "phy_write[%02x] = %04x\n", reg, value); - if (!db->in_timeout) + if (!db->in_timeout) { mutex_lock(&db->addr_lock); - spin_lock_irqsave(&db->lock, flags); - + spin_lock_irqsave(&db->lock, flags); + } /* Save previous register address */ reg_save = readb(db->io_addr); @@ -356,11 +356,13 @@ static void dm9000_msleep(struct board_info *db, unsigned int ms) iow(db, DM9000_EPCR, EPCR_EPOS | EPCR_ERPRW); writeb(reg_save, db->io_addr); - spin_unlock_irqrestore(&db->lock, flags); + if (!db->in_timeout) + spin_unlock_irqrestore(&db->lock, flags); dm9000_msleep(db, 1); /* Wait write complete */ - spin_lock_irqsave(&db->lock, flags); + if (!db->in_timeout) + spin_lock_irqsave(&db->lock, flags); reg_save = readb(db->io_addr); iow(db, DM9000_EPCR, 0x0); /* Clear phyxcer write command */ @@ -368,9 +370,11 @@ static void dm9000_msleep(struct board_info *db, unsigned int ms) /* restore the previous address */ writeb(reg_save, db->io_addr); - spin_unlock_irqrestore(&db->lock, flags); - if (!db->in_timeout) + if (!db->in_timeout) { + spin_unlock_irqrestore(&db->lock, flags); + mutex_unlock(&db->addr_lock); + } } /* dm9000_set_io -- 1.9.1
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