APPLIED: [Resend][PATCH][SRU][B] UBUNTU: SAUCE: mfd: intel-lpss: add quirk for Dell XPS 13 7390 2-in-1

[Kleber Souza]

On 01.10.19 04:57, AceLan Kao wrote:
> BugLink: https://bugs.launchpad.net/bugs/1845584
> 
> The memory region intel-lpss-pci uses has been declared as
> write-combining
> [    0.001728]   5 base 4000000000 mask 6000000000 write-combining
> This leads to the system hangs up during booting up.
> 
> Tuowen Zhao(ztuowen at gmail.com) provides a diff patch for intel-lpss
> driver to claim to use un-cacheable memory while calling
> __devm_ioremap(), and it works well. But it haven't been accepted by
> maintainer yet.
> 
> To avoid the potential impact on other machines, I add a quirk to list
> the machines which has the write-combining area in MTRR which overlaps
> with the address that intel-lpss uses, only the machines in the list
> pass the DEVM_IOREMAP_UC to __devm_ioremap().
> 
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=203485
> Signed-off-by: AceLan Kao <acelan.kao at canonical.com>

Applied to bionic/master-next branch.

Thanks,
Kleber

> ---
>  drivers/mfd/intel-lpss.c | 20 ++++++++++++++++++--
>  include/linux/io.h       |  2 ++
>  lib/devres.c             | 29 +++++++++++++++++++++++++++++
>  3 files changed, 49 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mfd/intel-lpss.c b/drivers/mfd/intel-lpss.c
> index 2d1b9cc7b384..1f3777a9857e 100644
> --- a/drivers/mfd/intel-lpss.c
> +++ b/drivers/mfd/intel-lpss.c
> @@ -17,6 +17,7 @@
>  #include <linux/clkdev.h>
>  #include <linux/clk-provider.h>
>  #include <linux/debugfs.h>
> +#include <linux/dmi.h>
>  #include <linux/idr.h>
>  #include <linux/ioport.h>
>  #include <linux/kernel.h>
> @@ -130,6 +131,17 @@ static const struct mfd_cell intel_lpss_spi_cell = {
>  static DEFINE_IDA(intel_lpss_devid_ida);
>  static struct dentry *intel_lpss_debugfs;
>  
> +static const struct dmi_system_id mtrr_large_wc_region[] = {
> +	{
> +		.ident = "Dell Computer Corporation",
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "XPS 13 7390 2-in-1"),
> +		},
> +	},
> +	{ }
> +};
> +
>  static int intel_lpss_request_dma_module(const char *name)
>  {
>  	static bool intel_lpss_dma_requested;
> @@ -397,8 +409,12 @@ int intel_lpss_probe(struct device *dev,
>  	if (!lpss)
>  		return -ENOMEM;
>  
> -	lpss->priv = devm_ioremap(dev, info->mem->start + LPSS_PRIV_OFFSET,
> -				  LPSS_PRIV_SIZE);
> +	if (dmi_check_system(mtrr_large_wc_region))
> +		lpss->priv = devm_ioremap_uc(dev, info->mem->start + LPSS_PRIV_OFFSET,
> +					     LPSS_PRIV_SIZE);
> +	else
> +		lpss->priv = devm_ioremap(dev, info->mem->start + LPSS_PRIV_OFFSET,
> +					  LPSS_PRIV_SIZE);
>  	if (!lpss->priv)
>  		return -ENOMEM;
>  
> diff --git a/include/linux/io.h b/include/linux/io.h
> index 32e30e8fb9db..da39ff89df65 100644
> --- a/include/linux/io.h
> +++ b/include/linux/io.h
> @@ -75,6 +75,8 @@ static inline void devm_ioport_unmap(struct device *dev, void __iomem *addr)
>  
>  void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
>  			   resource_size_t size);
> +void __iomem *devm_ioremap_uc(struct device *dev, resource_size_t offset,
> +				   resource_size_t size);
>  void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
>  				   resource_size_t size);
>  void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset,
> diff --git a/lib/devres.c b/lib/devres.c
> index 5f2aedd58bc5..d5286472fcbc 100644
> --- a/lib/devres.c
> +++ b/lib/devres.c
> @@ -43,6 +43,35 @@ void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
>  }
>  EXPORT_SYMBOL(devm_ioremap);
>  
> +/**
> + * devm_ioremap_uc - Managed ioremap_uc()
> + * @dev: Generic device to remap IO address for
> + * @offset: Resource address to map
> + * @size: Size of map
> + *
> + * Managed ioremap_uc().  Map is automatically unmapped on driver detach.
> + */
> +void __iomem *devm_ioremap_uc(struct device *dev, resource_size_t offset,
> +			      resource_size_t size)
> +{
> +	void __iomem **ptr, *addr;
> +
> +	ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
> +	if (!ptr)
> +		return NULL;
> +
> +	addr = ioremap_uc(offset, size);
> +	if (addr) {
> +		*ptr = addr;
> +		devres_add(dev, ptr);
> +	} else
> +		devres_free(ptr);
> +
> +	return addr;
> +}
> +EXPORT_SYMBOL(devm_ioremap_uc);
> +
> +
>  /**
>   * devm_ioremap_nocache - Managed ioremap_nocache()
>   * @dev: Generic device to remap IO address for
>