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    SubjectRe: [PATCH 1/4] net/macb: only probe queues once and use stored values
    Hi Nicolas,

    There is a little mistake in this patch, which will prevent the GEM from
    working properly:

    Le 27/03/2015 16:34, Nicolas Ferre a écrit :
    > When merging at91_ether and macb driver during 421d9df0628b (net/macb: merge
    > at91_ether driver into macb driver) the probe function has been split. The code
    > dealing with initialization of queues is now moved in macb_init() which needs
    > information computed in the parent macb_probe() function.
    > So, add the queue_mask information to the private structure and use it when
    > needed in macb_init().
    >
    > Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
    > Cc: Cyrille Pitchen <cyrille.pitchen@atmel.com>
    > Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
    > ---
    > drivers/net/ethernet/cadence/macb.c | 9 ++++-----
    > drivers/net/ethernet/cadence/macb.h | 1 +
    > 2 files changed, 5 insertions(+), 5 deletions(-)
    >
    > diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
    > index a0a04b3638e6..b710768172d9 100644
    > --- a/drivers/net/ethernet/cadence/macb.c
    > +++ b/drivers/net/ethernet/cadence/macb.c
    > @@ -2180,7 +2180,7 @@ static void macb_probe_queues(void __iomem *mem,
    > static int macb_init(struct platform_device *pdev)
    > {
    > struct net_device *dev = platform_get_drvdata(pdev);
    > - unsigned int hw_q, queue_mask, q, num_queues;
    > + unsigned int hw_q, q;
    > struct macb *bp = netdev_priv(dev);
    > struct macb_queue *queue;
    > int err;
    > @@ -2226,10 +2226,8 @@ static int macb_init(struct platform_device *pdev)
    > * register mapping but we don't want to test the queue index then
    > * compute the corresponding register offset at run time.
    > */
    > - macb_probe_queues(bp->regs, &queue_mask, &num_queues);
    > -
    > - for (hw_q = 0, q = 0; hw_q < MACB_MAX_QUEUES; ++hw_q) {
    > - if (!(queue_mask & (1 << hw_q)))
    > + for (hw_q = 0, q = 0; hw_q < bp->num_queues; ++hw_q) {
    > + if (!(bp->queue_mask & (1 << hw_q)))
    > continue;

    The exit condition of the for loop must remain "hw_q < MACB_MAX_QUEUES" and
    should not be replaced by "hw_q < bp->num_queues".
    Indeed there can be only 2 queues, for instance queue0 and queue7. So if you
    change the exit conditon of the loop, queue7 won't be initialized and HRESP
    errors will occur.
    >
    > queue = &bp->queues[q];
    > @@ -2715,6 +2713,7 @@ static int macb_probe(struct platform_device *pdev)
    > bp->dev = dev;
    > bp->regs = mem;
    > bp->num_queues = num_queues;
    > + bp->queue_mask = queue_mask;
    > spin_lock_init(&bp->lock);
    >
    > platform_set_drvdata(pdev, dev);
    > diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
    > index bc6e35c40822..0b6afac91bfe 100644
    > --- a/drivers/net/ethernet/cadence/macb.h
    > +++ b/drivers/net/ethernet/cadence/macb.h
    > @@ -785,6 +785,7 @@ struct macb {
    > size_t rx_buffer_size;
    >
    > unsigned int num_queues;
    > + unsigned int queue_mask;
    > struct macb_queue queues[MACB_MAX_QUEUES];
    >
    > spinlock_t lock;
    >

    Best Regards,

    Cyrille


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