[v4,4/6] PCI: rcar: Poll more often in rcar_pcie_wait_for_dl()
diff mbox series

Message ID 20180524143624.26718-5-marek.vasut+renesas@gmail.com
State Accepted
Delegated to: Lorenzo Pieralisi
Headers show
Series
  • PCI: rcar: Failpath fixes
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Commit Message

Marek Vasut May 24, 2018, 2:36 p.m. UTC
The data link active signal usually takes ~20 uSec to be asserted,
poll the bit more often to avoid useless delays in this function.
Use udelay() instead of usleep() for such a small delay as suggested
by the timer documentation and because this will be used in atomic
context later on when the suspend/resume patches land.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Phil Edworthy <phil.edworthy@renesas.com>
Cc: Simon Horman <horms+renesas@verge.net.au>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: linux-renesas-soc@vger.kernel.org
---
V2: s/content/context in commit message
V3: Add cpu_relax()
V4: Rebase on top of Lorenzo's pci/rcar, fix up the rebase breakage
    induced by patches therein
---
 drivers/pci/host/pcie-rcar.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Simon Horman May 28, 2018, 8:53 a.m. UTC | #1
On Thu, May 24, 2018 at 04:36:22PM +0200, Marek Vasut wrote:
> The data link active signal usually takes ~20 uSec to be asserted,
> poll the bit more often to avoid useless delays in this function.
> Use udelay() instead of usleep() for such a small delay as suggested
> by the timer documentation and because this will be used in atomic
> context later on when the suspend/resume patches land.
> 
> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
> Cc: Geert Uytterhoeven <geert+renesas@glider.be>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Phil Edworthy <phil.edworthy@renesas.com>
> Cc: Simon Horman <horms+renesas@verge.net.au>
> Cc: Wolfram Sang <wsa@the-dreams.de>
> Cc: linux-renesas-soc@vger.kernel.org

Acked-by: Simon Horman <horms+renesas@verge.net.au>

Patch
diff mbox series

diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c
index d6a7e8482dcf..4843a4dc6059 100644
--- a/drivers/pci/host/pcie-rcar.c
+++ b/drivers/pci/host/pcie-rcar.c
@@ -546,13 +546,14 @@  static int rcar_pcie_wait_for_phyrdy(struct rcar_pcie *pcie)
 
 static int rcar_pcie_wait_for_dl(struct rcar_pcie *pcie)
 {
-	unsigned int timeout = 10;
+	unsigned int timeout = 10000;
 
 	while (timeout--) {
 		if ((rcar_pci_read_reg(pcie, PCIETSTR) & DATA_LINK_ACTIVE))
 			return 0;
 
-		msleep(5);
+		udelay(5);
+		cpu_relax();
 	}
 
 	return -ETIMEDOUT;