On Mon, 2021-10-11 at 18:38 +0300, Boris Lysov wrote: > 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 Hi, This patch only applies to APDMA(application processor DMA) and does not use GDMA(Generic DMA).In addition, the file i2c-mt65xx.c only supports APDMA mode by default. If APDMA address is not configured in dts, i2c transmission will be fail.thx~
