| Message ID | 20180522122420.24002-1-marek.vasut+renesas@gmail.com |
|---|---|
| State | Accepted |
| Delegated to: | Lorenzo Pieralisi |
| Headers | show |
| Series | [V3] PCI: rcar: Poll more often in rcar_pcie_wait_for_dl() | expand |
On Tue, May 22, 2018 at 02:24:20PM +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: 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 Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
On Tue, May 22, 2018 at 02:24:20PM +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: 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() > --- > drivers/pci/host/pcie-rcar.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) Applied to pci/rcar for v4.18, thanks. Lorenzo > diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c > index 5c365f743df5..3aa6fe5f2d64 100644 > --- a/drivers/pci/host/pcie-rcar.c > +++ b/drivers/pci/host/pcie-rcar.c > @@ -529,13 +529,14 @@ static void phy_write_reg(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; > -- > 2.16.2 >
diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c index 5c365f743df5..3aa6fe5f2d64 100644 --- a/drivers/pci/host/pcie-rcar.c +++ b/drivers/pci/host/pcie-rcar.c @@ -529,13 +529,14 @@ static void phy_write_reg(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;
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: 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() --- drivers/pci/host/pcie-rcar.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)