Hi,
On Tue, Feb 07 2012, r66093@xxxxxxxxxxxxx wrote:
> From: Jerry Huang <Chang-Ming.Huang@xxxxxxxxxxxxx>
>
> SD card read was failing (data crc error)on some cards at
> maximum possible frequency on P1010(CCB frequency set to 400MHz).
> Some clock deviations are also observed at this frequency.
> Hence reduced the mmc clock freq.
>
> Signed-off-by: Priyanka Jain <Priyanka.Jain@xxxxxxxxxxxxx>
> Singed-off-by: Jerry Huang <Chang-Ming.Huang@xxxxxxxxxxxxx>
> CC: Chris Ball <cjb@xxxxxxxxxx>
> Acked-by: Anton Vorontsov <cbouatmailru@xxxxxxxxx>
> ---
> changes for v2:
> - change the property to compatible for quirks
> changes for v3:
> - fix one compile error
> changes for v4:
> - use hooks to suspend/resume the special platform
> changes for v5:
> - add the Acked-by
> changes for v6:
> - move the workaround codes to special platform from header file
>
> drivers/mmc/host/sdhci-of-esdhc.c | 18 +++++++++++++++++-
> drivers/mmc/host/sdhci-pltfm.c | 3 +++
> include/linux/mmc/sdhci.h | 3 +++
> 3 files changed, 23 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
> index 2ef52f4..a79e6e8 100644
> --- a/drivers/mmc/host/sdhci-of-esdhc.c
> +++ b/drivers/mmc/host/sdhci-of-esdhc.c
> @@ -114,6 +114,22 @@ static unsigned int esdhc_of_get_min_clock(struct sdhci_host *host)
> return pltfm_host->clock / 256 / 16;
> }
>
> +static void esdhc_of_set_clock(struct sdhci_host *host, unsigned int clock)
> +{
> + if (clock == 0) {
> + host->clock = clock;
> + return;
> + }
> +
> + if (host->quirks2 & SDHCI_QUIRK2_RELAX_FREQ) {
> + if (clock > 20000000)
> + clock -= 5000000;
> + if (clock > 40000000)
> + clock -= 5000000;
> + }
> + esdhc_set_clock(host, clock);
> +}
> +
> #ifdef CONFIG_PM
> static u32 esdhc_proctl;
> static void esdhc_of_suspend(struct sdhci_host *host)
> @@ -135,7 +151,7 @@ static struct sdhci_ops sdhci_esdhc_ops = {
> .write_l = sdhci_be32bs_writel,
> .write_w = esdhc_writew,
> .write_b = esdhc_writeb,
> - .set_clock = esdhc_set_clock,
> + .set_clock = esdhc_of_set_clock,
> .enable_dma = esdhc_of_enable_dma,
> .get_max_clock = esdhc_of_get_max_clock,
> .get_min_clock = esdhc_of_get_min_clock,
> diff --git a/drivers/mmc/host/sdhci-pltfm.c b/drivers/mmc/host/sdhci-pltfm.c
> index c5c2a48..0705838 100644
> --- a/drivers/mmc/host/sdhci-pltfm.c
> +++ b/drivers/mmc/host/sdhci-pltfm.c
> @@ -79,6 +79,9 @@ void sdhci_get_of_property(struct platform_device *pdev)
> of_device_is_compatible(np, "fsl,mpc8536-esdhc"))
> host->quirks |= SDHCI_QUIRK_BROKEN_TIMEOUT_VAL;
>
> + if (of_device_is_compatible(np, "fsl,p1010-esdhc"))
> + host->quirks2 |= SDHCI_QUIRK2_RELAX_FREQ;
> +
> clk = of_get_property(np, "clock-frequency", &size);
> if (clk && size == sizeof(*clk) && *clk)
> pltfm_host->clock = be32_to_cpup(clk);
> diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
> index c750f85..2418c91 100644
> --- a/include/linux/mmc/sdhci.h
> +++ b/include/linux/mmc/sdhci.h
> @@ -90,6 +90,9 @@ struct sdhci_host {
>
> unsigned int quirks2; /* More deviations from spec. */
>
> +/* Controller operates the cards at reduced frequency */
> +#define SDHCI_QUIRK2_RELAX_FREQ (1<<0)
> +
> int irq; /* Device IRQ */
> void __iomem *ioaddr; /* Mapped address */
This looks identical to the previous patch version to me? You're still
defining a new quirk in include/linux/mmc/sdhci.h, which is what I don't
want you to do for a driver-local quirk.
Thanks,
- Chris.
--
Chris Ball <cjb@xxxxxxxxxx> <http://printf.net/>
One Laptop Per Child
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