On Sun, 10 Oct 2021 15:05:13 +0800 Kewei Xu <kewei.xu@xxxxxxxxxxxx> wrote: > When a timeout error occurs in i2c transter, it is usually related > to the i2c/dma IP hardware configuration. Therefore, the purpose of > this patch is to dump the key register values of i2c/dma when a > timeout occurs in i2c for debugging. > > Signed-off-by: Kewei Xu <kewei.xu@xxxxxxxxxxxx> > Reviewed-by: Qii Wang <qii.wang@xxxxxxxxxxxx> I would like to test this patchset on one of supported platforms, an mt6577-powered device. This driver requires a DMA base... > i2c->pdmabase = devm_ioremap_resource(&pdev->dev, res); > if (IS_ERR(i2c->pdmabase)) > return PTR_ERR(i2c->pdmabase); ... however I am not sure what address should I specify in the .dts file. While other i2c busses supported by this driver such as mt6589 [1][2] and mt6797 [3] have designated DMA for I2C, mt6577 seems to lack dedicated DMA engine for I2C [4][5]. Do I need to specify the Generic DMA base address [4] instead? Worth mentioning I brought up this issue in the past [5][6]. [1] ALPS.KK1.MP5.V1.3_EASTAEON89_WET_KK source code (downstream) [2] MT6589 HSPA+ Smartphone Application Processor Datasheet v1.0, page 869 [3] MT6797 LTE-A Smartphone Application Processor Register Table (Part 1) v1.1, page 1796 [4] MT6577 HSPA Smartphone Application Processor Datasheet v0.94, page 547 [5] ALPS.JB.MP.V1.19_MBK77_TB_JB source code (downstream) [6] https://marc.info/?l=devicetree&m=159949247901831&w=2 [7] https://marc.info/?l=linux-i2c&m=159939730714187&w=2
