[alsa-devel] [PATCH v2 0/3] Switch to ioremap_wc in the SRAM allocator code
Fix alignment faults seen during play-back of files with specific sampling rates such as 44.1K. This is based on the discussion here: http://www.spinics.net/lists/arm-kernel/msg384647.html
Patch 1 is needed as m32r arch does not define ioremap_wc. Patch 2 adds a resource managed helper function for ioremap_wc which is used in patch 3.
Changes since v1: - Fix the compilation error with m32r due to missing ioremap_wc definition. - Fixed minor indentation issues.
Note: Other architectures either have ioremap_wc defined or are including generic "io.h"/"iomap.h". c6x arch is the only one I am not sure of.
Abhilash Kesavan (3): m32r: add definition of ioremap_wc to io.h lib: devres: add a helper function for ioremap_wc misc: sram: switch to ioremap_wc from ioremap
Documentation/driver-model/devres.txt | 1 + arch/m32r/include/asm/io.h | 1 + drivers/misc/sram.c | 17 ++++++++++++++--- include/linux/io.h | 2 ++ lib/devres.c | 28 ++++++++++++++++++++++++++++ 5 files changed, 46 insertions(+), 3 deletions(-)
Before adding a resource managed ioremap_wc function, we need to have ioremap_wc defined for m32r to prevent build errors.
Signed-off-by: Abhilash Kesavan a.kesavan@samsung.com --- arch/m32r/include/asm/io.h | 1 + 1 file changed, 1 insertion(+)
diff --git a/arch/m32r/include/asm/io.h b/arch/m32r/include/asm/io.h index 6e7787f..9cc00db 100644 --- a/arch/m32r/include/asm/io.h +++ b/arch/m32r/include/asm/io.h @@ -67,6 +67,7 @@ static inline void __iomem *ioremap(unsigned long offset, unsigned long size)
extern void iounmap(volatile void __iomem *addr); #define ioremap_nocache(off,size) ioremap(off,size) +#define ioremap_wc ioremap_nocache
/* * IO bus memory addresses are also 1:1 with the physical address
Implement a resource managed writecombine ioremap function.
Signed-off-by: Abhilash Kesavan a.kesavan@samsung.com --- Documentation/driver-model/devres.txt | 1 + include/linux/io.h | 2 ++ lib/devres.c | 28 ++++++++++++++++++++++++++++ 3 files changed, 31 insertions(+)
diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index 6d1e8ee..7fe7fd2 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -276,6 +276,7 @@ IOMAP devm_ioport_unmap() devm_ioremap() devm_ioremap_nocache() + devm_ioremap_wc() devm_ioremap_resource() : checks resource, requests memory region, ioremaps devm_iounmap() pcim_iomap() diff --git a/include/linux/io.h b/include/linux/io.h index fa02e55..42b33f0 100644 --- a/include/linux/io.h +++ b/include/linux/io.h @@ -64,6 +64,8 @@ void __iomem *devm_ioremap(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, + resource_size_t size); void devm_iounmap(struct device *dev, void __iomem *addr); int check_signature(const volatile void __iomem *io_addr, const unsigned char *signature, int length); diff --git a/lib/devres.c b/lib/devres.c index 0f1dd2e..fbe2aac 100644 --- a/lib/devres.c +++ b/lib/devres.c @@ -72,6 +72,34 @@ void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset, EXPORT_SYMBOL(devm_ioremap_nocache);
/** + * devm_ioremap_wc - Managed ioremap_wc() + * @dev: Generic device to remap IO address for + * @offset: BUS offset to map + * @size: Size of map + * + * Managed ioremap_wc(). Map is automatically unmapped on driver detach. + */ +void __iomem *devm_ioremap_wc(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_wc(offset, size); + if (addr) { + *ptr = addr; + devres_add(dev, ptr); + } else + devres_free(ptr); + + return addr; +} +EXPORT_SYMBOL(devm_ioremap_wc); + +/** * devm_iounmap - Managed iounmap() * @dev: Generic device to unmap for * @addr: Address to unmap
Currently, the SRAM allocator returns device memory via ioremap. This causes issues on ARM64 when the internal SoC SRAM allocated by the generic sram driver is used for audio playback. The destination buffer address (which is ioremapped SRAM) is not 64-bit aligned for certain streams (e.g. 44.1k sampling rate). In such cases we get unhandled alignment faults. Use ioremap_wc in place of ioremap which gives us normal non-cacheable memory instead of device memory.
Signed-off-by: Abhilash Kesavan a.kesavan@samsung.com Tested-by: Tony Lindgren tony@atomide.com Tested-by: Heiko Stuebner heiko@sntech.de --- drivers/misc/sram.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c index 21181fa..15b4d4e 100644 --- a/drivers/misc/sram.c +++ b/drivers/misc/sram.c @@ -69,12 +69,23 @@ static int sram_probe(struct platform_device *pdev) INIT_LIST_HEAD(&reserve_list);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - virt_base = devm_ioremap_resource(&pdev->dev, res); - if (IS_ERR(virt_base)) - return PTR_ERR(virt_base); + if (!res) { + dev_err(&pdev->dev, "found no memory resource\n"); + return -EINVAL; + }
size = resource_size(res);
+ if (!devm_request_mem_region(&pdev->dev, + res->start, size, pdev->name)) { + dev_err(&pdev->dev, "could not request region for resource\n"); + return -EBUSY; + } + + virt_base = devm_ioremap_wc(&pdev->dev, res->start, size); + if (IS_ERR(virt_base)) + return PTR_ERR(virt_base); + sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL); if (!sram) return -ENOMEM;
Am Freitag, den 06.02.2015, 19:15 +0530 schrieb Abhilash Kesavan:
Currently, the SRAM allocator returns device memory via ioremap. This causes issues on ARM64 when the internal SoC SRAM allocated by the generic sram driver is used for audio playback. The destination buffer address (which is ioremapped SRAM) is not 64-bit aligned for certain streams (e.g. 44.1k sampling rate). In such cases we get unhandled alignment faults. Use ioremap_wc in place of ioremap which gives us normal non-cacheable memory instead of device memory.
Signed-off-by: Abhilash Kesavan a.kesavan@samsung.com Tested-by: Tony Lindgren tony@atomide.com Tested-by: Heiko Stuebner heiko@sntech.de
Acked-by: Philipp Zabel p.zabel@pengutronix.de
regards Philipp
On Fri, Feb 06, 2015 at 01:45:25PM +0000, Abhilash Kesavan wrote:
Fix alignment faults seen during play-back of files with specific sampling rates such as 44.1K. This is based on the discussion here: http://www.spinics.net/lists/arm-kernel/msg384647.html
Patch 1 is needed as m32r arch does not define ioremap_wc. Patch 2 adds a resource managed helper function for ioremap_wc which is used in patch 3.
Changes since v1:
- Fix the compilation error with m32r due to missing ioremap_wc
definition.
- Fixed minor indentation issues.
Note: Other architectures either have ioremap_wc defined or are including generic "io.h"/"iomap.h". c6x arch is the only one I am not sure of.
Abhilash Kesavan (3): m32r: add definition of ioremap_wc to io.h lib: devres: add a helper function for ioremap_wc misc: sram: switch to ioremap_wc from ioremap
Documentation/driver-model/devres.txt | 1 + arch/m32r/include/asm/io.h | 1 + drivers/misc/sram.c | 17 ++++++++++++++--- include/linux/io.h | 2 ++ lib/devres.c | 28 ++++++++++++++++++++++++++++ 5 files changed, 46 insertions(+), 3 deletions(-)
For the series:
Acked-by: Catalin Marinas catalin.marinas@arm.com
Thanks.
Hi Greg,
On Fri, Feb 6, 2015 at 9:14 PM, Catalin Marinas catalin.marinas@arm.com wrote:
On Fri, Feb 06, 2015 at 01:45:25PM +0000, Abhilash Kesavan wrote:
Fix alignment faults seen during play-back of files with specific sampling rates such as 44.1K. This is based on the discussion here: http://www.spinics.net/lists/arm-kernel/msg384647.html
Patch 1 is needed as m32r arch does not define ioremap_wc. Patch 2 adds a resource managed helper function for ioremap_wc which is used in patch 3.
Changes since v1: - Fix the compilation error with m32r due to missing ioremap_wc definition. - Fixed minor indentation issues.
Note: Other architectures either have ioremap_wc defined or are including generic "io.h"/"iomap.h". c6x arch is the only one I am not sure of.
Abhilash Kesavan (3): m32r: add definition of ioremap_wc to io.h lib: devres: add a helper function for ioremap_wc misc: sram: switch to ioremap_wc from ioremap
Documentation/driver-model/devres.txt | 1 + arch/m32r/include/asm/io.h | 1 + drivers/misc/sram.c | 17 ++++++++++++++--- include/linux/io.h | 2 ++ lib/devres.c | 28 ++++++++++++++++++++++++++++ 5 files changed, 46 insertions(+), 3 deletions(-)
For the series:
Acked-by: Catalin Marinas catalin.marinas@arm.com
These patches still apply cleanly on linux-next and have been ack'ed by Catalin and Philipp. Would you like me to collect the tags and resend the series or can they be applied as is ?
Thanks, Abhilash
Thanks.
-- Catalin _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
On Sun, Mar 01, 2015 at 10:00:37PM +0530, Abhilash Kesavan wrote:
Hi Greg,
On Fri, Feb 6, 2015 at 9:14 PM, Catalin Marinas catalin.marinas@arm.com wrote:
On Fri, Feb 06, 2015 at 01:45:25PM +0000, Abhilash Kesavan wrote:
Fix alignment faults seen during play-back of files with specific sampling rates such as 44.1K. This is based on the discussion here: http://www.spinics.net/lists/arm-kernel/msg384647.html
Patch 1 is needed as m32r arch does not define ioremap_wc. Patch 2 adds a resource managed helper function for ioremap_wc which is used in patch 3.
Changes since v1: - Fix the compilation error with m32r due to missing ioremap_wc definition. - Fixed minor indentation issues.
Note: Other architectures either have ioremap_wc defined or are including generic "io.h"/"iomap.h". c6x arch is the only one I am not sure of.
Abhilash Kesavan (3): m32r: add definition of ioremap_wc to io.h lib: devres: add a helper function for ioremap_wc misc: sram: switch to ioremap_wc from ioremap
Documentation/driver-model/devres.txt | 1 + arch/m32r/include/asm/io.h | 1 + drivers/misc/sram.c | 17 ++++++++++++++--- include/linux/io.h | 2 ++ lib/devres.c | 28 ++++++++++++++++++++++++++++ 5 files changed, 46 insertions(+), 3 deletions(-)
For the series:
Acked-by: Catalin Marinas catalin.marinas@arm.com
These patches still apply cleanly on linux-next and have been ack'ed by Catalin and Philipp. Would you like me to collect the tags and resend the series or can they be applied as is ?
I can take them as-is, thanks.
greg k-h
participants (5)
-
Abhilash Kesavan -
Abhilash Kesavan -
Catalin Marinas -
gregkh＠linuxfoundation.org -
Philipp Zabel