ahci: retry enabling AHCI a few times before spitting out WARN_ON() (15fe982e) · Commits · 戴 / test

Some chips need AHCI_EN set more than once to actually set it. Try a few times before giving up and spitting out WARN_ON(). Signed-off-by:

Tejun Heo <htejun@gmail.com> Cc: Peer Chen <pchen@nvidia.com> Cc: Volker Armin Hemmann <volker.armin.hemmann@tu-clausthal.de> Signed-off-by:

drivers/ata/ahci.c

+13 −2

Original line number	Diff line number	Diff line
		@@ -556,16 +556,27 @@ static inline void __iomem ahci_port_base(struct ata_port ap)

		static void ahci_enable_ahci(void __iomem *mmio)
		{
		int i;
		u32 tmp;

		/* turn on AHCI_EN */
		tmp = readl(mmio + HOST_CTL);
		if (!(tmp & HOST_AHCI_EN)) {
		if (tmp & HOST_AHCI_EN)
		return;

		/* Some controllers need AHCI_EN to be written multiple times.
		* Try a few times before giving up.
		*/
		for (i = 0; i < 5; i++) {
		tmp \|= HOST_AHCI_EN;
		writel(tmp, mmio + HOST_CTL);
		tmp = readl(mmio + HOST_CTL); /* flush && sanity check */
		WARN_ON(!(tmp & HOST_AHCI_EN));
		if (tmp & HOST_AHCI_EN)
		return;
		msleep(10);
		}

		WARN_ON(1);
		}

		/**