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    SubjectRe: [PATCH 1/3] irqchip/gic-v3: Fix GICR_CTLR.RWP polling
    On Tue, Mar 15, 2022 at 04:50:32PM +0000, Marc Zyngier wrote:
    > It turns out that our polling of RWP is totally wrong when checking
    > for it in the redistributors, as we test the *distributor* bit index,
    > whereas it is a different bit number in the RDs... Oopsie boo.
    >
    > This is embarassing. Not only because it is wrong, but also because
    > it took *8 years* to notice the blunder...
    >
    > Just fix the damn thing.
    >
    > Fixes: 021f653791ad ("irqchip: gic-v3: Initial support for GICv3")
    > Signed-off-by: Marc Zyngier <maz@kernel.org>
    > Cc: stable@vger.kernel.org
    > ---
    > drivers/irqchip/irq-gic-v3.c | 8 ++++----
    > 1 file changed, 4 insertions(+), 4 deletions(-)

    Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

    > diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
    > index 5e935d97207d..736163d36b13 100644
    > --- a/drivers/irqchip/irq-gic-v3.c
    > +++ b/drivers/irqchip/irq-gic-v3.c
    > @@ -206,11 +206,11 @@ static inline void __iomem *gic_dist_base(struct irq_data *d)
    > }
    > }
    >
    > -static void gic_do_wait_for_rwp(void __iomem *base)
    > +static void gic_do_wait_for_rwp(void __iomem *base, u32 bit)
    > {
    > u32 count = 1000000; /* 1s! */
    >
    > - while (readl_relaxed(base + GICD_CTLR) & GICD_CTLR_RWP) {
    > + while (readl_relaxed(base + GICD_CTLR) & bit) {
    > count--;
    > if (!count) {
    > pr_err_ratelimited("RWP timeout, gone fishing\n");
    > @@ -224,13 +224,13 @@ static void gic_do_wait_for_rwp(void __iomem *base)
    > /* Wait for completion of a distributor change */
    > static void gic_dist_wait_for_rwp(void)
    > {
    > - gic_do_wait_for_rwp(gic_data.dist_base);
    > + gic_do_wait_for_rwp(gic_data.dist_base, GICD_CTLR_RWP);
    > }
    >
    > /* Wait for completion of a redistributor change */
    > static void gic_redist_wait_for_rwp(void)
    > {
    > - gic_do_wait_for_rwp(gic_data_rdist_rd_base());
    > + gic_do_wait_for_rwp(gic_data_rdist_rd_base(), GICR_CTLR_RWP);
    > }
    >
    > #ifdef CONFIG_ARM64
    > --
    > 2.34.1
    >

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