[v2,2/3] mmc: sunxi: Filter out unsupported modes declared in the device tree
diff mbox series

Message ID 20190205154225.14264-3-wens@csie.org
State New, archived
Headers show
Series
  • mmc: sunxi: Fix eMMC usage on H5 boards
Related show

Commit Message

Chen-Yu Tsai Feb. 5, 2019, 3:42 p.m. UTC
The MMC device tree bindings include properties used to signal various
signalling speed modes. Until now the sunxi driver was accepting them
without any further filtering, while the sunxi device trees were not
actually using them.

Since some of the H5 boards can not run at higher speed modes stably,
we are resorting to declaring the higher speed modes per-board.

Regardless, having boards declare modes and blindly following them,
even without proper support in the driver, is generally a bad thing.

Filter out all unsupported modes from the capabilities mask after
the device tree properties have been parsed.

Cc: <stable@vger.kernel.org>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>

---

This should be backported to stable kernels in case people try to run
new device trees (that declare newly supported modes) with old kernels.
---
 drivers/mmc/host/sunxi-mmc.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

Comments

Maxime Ripard Feb. 6, 2019, 12:20 p.m. UTC | #1
On Tue, Feb 05, 2019 at 11:42:24PM +0800, Chen-Yu Tsai wrote:
> The MMC device tree bindings include properties used to signal various
> signalling speed modes. Until now the sunxi driver was accepting them
> without any further filtering, while the sunxi device trees were not
> actually using them.
> 
> Since some of the H5 boards can not run at higher speed modes stably,
> we are resorting to declaring the higher speed modes per-board.
> 
> Regardless, having boards declare modes and blindly following them,
> even without proper support in the driver, is generally a bad thing.
> 
> Filter out all unsupported modes from the capabilities mask after
> the device tree properties have been parsed.
> 
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>

Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>

Maxime
Ulf Hansson Feb. 6, 2019, 3:14 p.m. UTC | #2
On Tue, 5 Feb 2019 at 16:42, Chen-Yu Tsai <wens@csie.org> wrote:
>
> The MMC device tree bindings include properties used to signal various
> signalling speed modes. Until now the sunxi driver was accepting them
> without any further filtering, while the sunxi device trees were not
> actually using them.
>
> Since some of the H5 boards can not run at higher speed modes stably,
> we are resorting to declaring the higher speed modes per-board.
>
> Regardless, having boards declare modes and blindly following them,
> even without proper support in the driver, is generally a bad thing.
>
> Filter out all unsupported modes from the capabilities mask after
> the device tree properties have been parsed.
>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
>

Applied for fixes, thanks!

Kind regards
Uffe


> ---
>
> This should be backported to stable kernels in case people try to run
> new device trees (that declare newly supported modes) with old kernels.
> ---
>  drivers/mmc/host/sunxi-mmc.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
>
> diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c
> index 7415af8c8ff6..70fadc976795 100644
> --- a/drivers/mmc/host/sunxi-mmc.c
> +++ b/drivers/mmc/host/sunxi-mmc.c
> @@ -1415,6 +1415,21 @@ static int sunxi_mmc_probe(struct platform_device *pdev)
>         if (ret)
>                 goto error_free_dma;
>
> +       /*
> +        * If we don't support delay chains in the SoC, we can't use any
> +        * of the higher speed modes. Mask them out in case the device
> +        * tree specifies the properties for them, which gets added to
> +        * the caps by mmc_of_parse() above.
> +        */
> +       if (!(host->cfg->clk_delays || host->use_new_timings)) {
> +               mmc->caps &= ~(MMC_CAP_3_3V_DDR | MMC_CAP_1_8V_DDR |
> +                              MMC_CAP_1_2V_DDR | MMC_CAP_UHS);
> +               mmc->caps2 &= ~MMC_CAP2_HS200;
> +       }
> +
> +       /* TODO: This driver doesn't support HS400 mode yet */
> +       mmc->caps2 &= ~MMC_CAP2_HS400;
> +
>         ret = sunxi_mmc_init_host(host);
>         if (ret)
>                 goto error_free_dma;
> --
> 2.20.1
>

Patch
diff mbox series

diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c
index 7415af8c8ff6..70fadc976795 100644
--- a/drivers/mmc/host/sunxi-mmc.c
+++ b/drivers/mmc/host/sunxi-mmc.c
@@ -1415,6 +1415,21 @@  static int sunxi_mmc_probe(struct platform_device *pdev)
 	if (ret)
 		goto error_free_dma;
 
+	/*
+	 * If we don't support delay chains in the SoC, we can't use any
+	 * of the higher speed modes. Mask them out in case the device
+	 * tree specifies the properties for them, which gets added to
+	 * the caps by mmc_of_parse() above.
+	 */
+	if (!(host->cfg->clk_delays || host->use_new_timings)) {
+		mmc->caps &= ~(MMC_CAP_3_3V_DDR | MMC_CAP_1_8V_DDR |
+			       MMC_CAP_1_2V_DDR | MMC_CAP_UHS);
+		mmc->caps2 &= ~MMC_CAP2_HS200;
+	}
+
+	/* TODO: This driver doesn't support HS400 mode yet */
+	mmc->caps2 &= ~MMC_CAP2_HS400;
+
 	ret = sunxi_mmc_init_host(host);
 	if (ret)
 		goto error_free_dma;