Hi,
-----Original Message----- From: Hans Verkuil hverkuil-cisco@xs4all.nl Sent: 2022年4月6日 17:47 To: Sandor Yu sandor.yu@nxp.com; dri-devel@lists.freedesktop.org; linux-kernel@vger.kernel.org; andrzej.hajda@intel.com; narmstrong@baylibre.com; robert.foss@linaro.org; Laurent.pinchart@ideasonboard.com; jonas@kwiboo.se; jernej.skrabec@gmail.com Cc: S.J. Wang shengjiu.wang@nxp.com; cai.huoqing@linux.dev; maxime@cerno.tech; harry.wentland@amd.com; amuel@sholland.org Subject: [EXT] Re: [PATCH v1 1/5] drm: bridge: dw_hdmi: cec: Add cec suspend/resume function
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Hi Sandor,
On 06/04/2022 10:48, Sandor.yu@nxp.com wrote:
From: Sandor Yu Sandor.yu@nxp.com
CEC interrupt status/mask and logical address registers will be reset when device enter suspend. It will cause cec fail to work after device resume. Add CEC suspend/resume functions, save these registers status when suspend and restore them when resume.
Signed-off-by: Sandor Yu Sandor.yu@nxp.com
drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c | 35 +++++++++++++++++++ 1 file changed, 35 insertions(+)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c index c8f44bcb298a..ceb619b32fde 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c @@ -18,6 +18,8 @@
#include "dw-hdmi-cec.h"
+static u8 cec_saved_regs[5];
Ewww, not a global. Just save it in struct dw_hdmi_cec.
enum { HDMI_IH_CEC_STAT0 = 0x0106, HDMI_IH_MUTE_CEC_STAT0 = 0x0186, @@ -306,11 +308,44
@@ static
int dw_hdmi_cec_remove(struct platform_device *pdev) return 0; }
+static int __maybe_unused dw_hdmi_cec_resume(struct device *dev) {
struct dw_hdmi_cec *cec = dev_get_drvdata(dev);/* Restore logical address and interrupt status/mask register */dw_hdmi_write(cec, cec_saved_regs[0], HDMI_CEC_ADDR_L);dw_hdmi_write(cec, cec_saved_regs[1], HDMI_CEC_ADDR_H);No need to store HDMI_CEC_ADDR_L/R, just use cec->addresses.
Agree, I will use it later.
dw_hdmi_write(cec, cec_saved_regs[2], HDMI_CEC_POLARITY);dw_hdmi_write(cec, cec_saved_regs[3], HDMI_CEC_MASK);dw_hdmi_write(cec, cec_saved_regs[4],HDMI_IH_MUTE_CEC_STAT0);
This doesn't call cec->ops->disable/enable. It might be better to just call dw_hdmi_cec_enable() and store the enable state in struct dw_hdmi_cec.
If call cec->ops->disable/enable in suspend/resume, CEC stack will be reset. CEC user such as EARC/ARC, the CEC link is expect keep in active after device resume. So I prefer only save those registers for better user experience.
Regards,
Hans
Thanks Sandor
return 0;+}
+static int __maybe_unused dw_hdmi_cec_suspend(struct device *dev) {
struct dw_hdmi_cec *cec = dev_get_drvdata(dev);/* store logical address and interrupt status/mask register */cec_saved_regs[0] = dw_hdmi_read(cec, HDMI_CEC_ADDR_L);cec_saved_regs[1] = dw_hdmi_read(cec, HDMI_CEC_ADDR_H);cec_saved_regs[2] = dw_hdmi_read(cec, HDMI_CEC_POLARITY);cec_saved_regs[3] = dw_hdmi_read(cec, HDMI_CEC_MASK);cec_saved_regs[4] = dw_hdmi_read(cec,HDMI_IH_MUTE_CEC_STAT0);
return 0;+}
+static const struct dev_pm_ops dw_hdmi_cec_pm = {
SET_SYSTEM_SLEEP_PM_OPS(dw_hdmi_cec_suspend,dw_hdmi_cec_resume)
+};
static struct platform_driver dw_hdmi_cec_driver = { .probe = dw_hdmi_cec_probe, .remove = dw_hdmi_cec_remove, .driver = { .name = "dw-hdmi-cec",
.pm = &dw_hdmi_cec_pm, },}; module_platform_driver(dw_hdmi_cec_driver);